.—_ —_—— ‘ —_—— fix TAXONOMEC AND LIMNOLOGECAL SI'UD'Y OF THE ALQAE {N LAKE LANSING fimis 6o: fhe 099m cf M. i. MICHIGAN. STATE UNIVERSITY Dennis Cob-inn Jackson ' ms THESIS J WW W W W \\3\\129336°°° LIBRARY Michigan State University L\ ABSTRACT A TAXONOMIC AND LIMNOLOGICAL STUDY OF THE ALGAE IN LAKE LANSING. by Dennis C. Jackson This study was designed to determine: (1) the general algal florisfic composition of the lake and to record the types of habitats where particular algal populations existed. (2) the monthiyand.seasonal (winter, spring and early summer) successions in the phytoplankton on quantitative and qualitative basis. (3) the monthly and seasonal successional (winter. spring, and early'summer) changes. which may occur in the process of Aufwuchs colonization on artificial substrates. Five permanent and eight incidental stations were established. At each of the five permanent stations plankton samples were collected and studied. All visible algae were collected from stones, rocks. etc., frem the incidentally sampled stations. Collections for the quantitative aspects of the study were made with a Kemmerer Sampler. concentrated with a Foerst Electric Centrifuge, and counted with a Palmer Counting Slide in conjuction with a Hhipple reticule plankton counting eyepiece. 'me Major Findings A total of 312 algal taxa are peported and all but 6 were collected in the course of this investigation.. There are 13 new records of which seven are new to Michigan and six new to North America. Fourteen are not identified to species and possibly represent previously undescribed taxa. The limnetic community is composed of organisms classified as l 2 Dennis C. Jackson euplanktonic. but also intermingled with these are organisms diaplaced from the littoral and_§ufwuchs communities.‘ The total number of phytoplankton fluctuated throughout the year, exhibiting a small mid- winter pulse and a large spring maximum. These fluCtuations are an expression of the total effect of the individual fluctuations of the organisms which compose the community. In the order of numerical abundance the algal divisions which contributed the largest quantity of organisms, to this phytOplankton were: the Chrysophyta, Cyanophyta, Chlorophyta and Pyrrhophyta. The littoral region is the most heterogeneous environment in the Lake and supports the largest number of taxa (237). These taxa belong to either the community of the plankton or to the Aufwuchs. Over 505% of the taxa occurring in the plankton are exclusiveky found in this region, and.the major portion of these are Desmids and other Chlorophyta. The Aufwuchs community can be classified according to the substrate upon which they develop,i.e., organic and inorganic. The community on stones is primarily composed of diatoms whereas the communities on the higher aquatic plants are usually dominated by filamentous green and blue-green algae. The Anfwuchs development and the complex succession of taxa on artificial substrates is related to a number of variables, such as space and the organisms present in the region. The rate of accumulation of this community is similar to that of the plankton community with a small midewinter pulse and a spring maximum. The major constituents of the Aufwuchs community are the diatoms and along with these basic constituents are a number of planktonic forms which become caught and tangled with the attached forms. The vertical distribution of the Aufwuchs is different not.only in.community composition but in 3 Dennis C. Jackson quantity as well. Whereas one might expect that the upper level would likely have a greater quantity of Aufwuchs due to light intensity, this usually is not the case. The investigation revealed that the regions of a lake are normally inhabited by associations of species in recognizable communities. These communities, however. are not rigidly delimited, nor are their compositions static and fixed. They are entities which in response to their environment are dynamic in composition time and space. A TAXOWIC AND LIMNOLOGICAL STUDY OF THE ALGAE IN LAKE LANSING By Dennis Cobian Jackson A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Botany and Plant Pathology 1963 - :37 (a l o 3 2! a/e l V)? ACKNOWLEDGst It is said that you give but little when you give of your possestions. It is when you give of yourself that you truly give. For this reason I wish to sincerely thank the following persons: Dr. G. W. Prescott, under whose guidance this study was done, for his friendship, assistance and generous, helpful advice throughout this investigation: Dr. Sebastian A. Guarrera, for his many helpful suggestions in the study of the Aufwuchs community; Dr. Jadwiga Sieminska, for her generous help in the translation of foreign publications used during the course of this investigation; all three, for being themselves, an inspiration to any phycologist. Thanks are due Dr. Henry Imshaug and Dr. John Cantlon, for their helpful suggestions and corrections in the writing of this thesis. Dr. John Beaman, Dr. Robert Bell, Dr. Everett Beneke, Dr. Hilbert Wade, and Dr. Loran Anderson, willingly read and corrected the final manuscript. I also wish to thank Mr. Herbert Graffius, Mrs. Elaine Hurst, Mr. David Kidd, Mr. John Schindler, Mr. H. human Davies, and Dr. Nural Islam for their encouragement. Last and certainly not least I wish to thank nnr wife Evelyn, for her numerous helps and encouragement . Dedicated To My Mother and Father iii use 91-: __00N_T_EN_ as Page I- INTRODUCTION 00.000.000.00...0.00.0.0...OOOIOOOOOOOOOOOOOOO. l A. Histony Of the Investigation OOOOOOOOOOOOOOO0.00.00.00. l B. Scope of the Study (Statement Problem) ................ 2 II“ lELAKE 00.00.00.000...0.0.0.0....C...............OOOOOOOQ 1‘ A. Location and.Immediate Surroundings ................... 4::- B. General PhYSica-l CharaCteristics .OOOOOOOOOOCOOOOOOOOOO C. General Chemical Characteristics ...................... \n D. Position and Description of the Stations .............. 6 III; METHODS AND MATERIALS 00.000000000000000.00000000000000000 10 A. Biological Techniques ................................. 10 Euplankton Qualitative ........................... lO EMplankton Quantitative ........................... ll Tychoplankton Qualitative ......................... 16 Aufwuchs Qualitative .............................. 17 B. Physical and Chemical Techniques .. 21 iv Iv. DATAANDMEASURMEN'B O...0.00.00...OOOOOOOOOOOOIOOOOOOCOO. A. Algae: Qualitative OOOOOOOOOOO...OOOOOOOOOOOOOOOOOOC... B. Mlmktm: Quantitative OOOOOOIOOOOOOOOOO...0000...... C. Aufwuchs: Qualitative and Quantitative ................ D. PWSical md aims-cal- OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO v- DIstSION OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO A. General ............................................... B. Algal Communities limnetic .......................................... Conclusions ................................... Littoral .......................................... Conclusions ................................... Aufwuchs on artificial substrates ................. conCluSions OOOOOOOOOOO0.0000000000000000000000 VI- SUWARY .00...OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO0.0.000... VII— SYSTEMATIC LIST 93 ALGAEyj LAKE LMEING VIII- PLATE .0...00.0.0.0...OOOOOOOOOOOOOO0.0.00.0...000...... Ix- BIBLImeYOCOOOOOOOOOOOO0.000000000COOOOCOOO0.0.0.000... Page 22 32 51 66 71 74 7h 102 104 108 171 210 r* us IS (g E?! GRAPH Page 1. 2. 7. 8. Percentage of each algal division occurring in three habitats.23 Average seasonal variation of the total phytoplankton ........24 Seasonal variation in the phytoplankton at station I .........25 Seasonal variation in the phytoplankton according to algal division ...............................................26 Seasonal variation in the phytoplankton at station III .......27 Seasonal variation in the phytoplakton according to algal division ...............................................28 Monthly variation of phytOplankton comparison between station II and III ...........................................29 Average quantity of Aufwuchs developed on artificial substrates .0OOOOOCOOOOOOCOOOOOOOO...0.0.0.000...OOOOOOOOOOOOOE LIST 9: TABLES TABLE Page I- Qualitative analysis of the algae in Lake Lansing .......... 33 11- Quantitative analysis of phytoplankton Station I ........... 51 III- Quantitative analysis of phytoplankton Station III ......... 58 IV; Quantitative analysis of phytoplankton Station II .......... 64 V- Qualitative analysis of AufWuchs on artificial substrates .. 67 F Bacteriological and chemical analysis made by the Michigan Department of Health .............................. 72 VII- Chemical analysis of surface waters of Lake Lansing ........ 73 A TAXONOMIC AND LIMNOLOGICAL STUDY OF THE ALGAE IN LAKE LANSING I . INTRODUCTION A. Histogy of the Investigation Lake lensing. although small, has played an important role as a recreational site for the surrounding communities. For over a hundred years its shores have been visited by bathers, fishermen, boat enthusi- asts. and biological classes collecting algae, higher aquatic plants and zoological specimens. In spite of the fact that many university classes have frequently visited the lake it has never been investigated as a biological entity. Furthermore very little has been done on the lake with reference to its limnological characteristics. The first known study was a survey by R. C. Ball and party. in 1938, undertaken for the Institute of Fisheries Research, a division of the Michigan Department of Conservation. In addition there was a threeamonth study of the phyto- plankton published by Tucker in 1957 and a recent report by Michigan Associates in 1960. The Ball survey included some chemical analyses and descriptions of some biological. and physical characteristics (nature of the bottom deposits etc.). The former, however, were mostly concerned with the higher aquatic vegetation and fish populations of the lake, hence the algae were but lightly treated. The Tucker publication. dealt with a number of Michigan lakes and was concerned with the relationship of phytoplankton periodicity to the nature of the physico—chemical environment. 1 The Michigan Associates' report concerns itself with the control of the nuisance weeds and makes no mention of algae. All of the reports have been of great value in supplying information toward an understanding of the existing conditions of the lake. The present investigation was undertaken to contribute to our inadequate knowledge of Lake Lansing algae, and to analyze the various community compositions (euplankton, tychoplankton, aufwuchs). The study was done under the quidance of Dr. G. W. Prescott. The field investiga- tion was carried out over a period of two years (September 1959 to June 1960, and September 1960 to June 1961), with the collections being made at weekly intervals, as regularly as possible. B. Scope of £22 Stugy Statement of the Problem This investigation had the following three primary objectives: 1- To determine the general algal floristic composition of the lake, and to record the types of habitats where particular algal populations existed. 2— To determine the monthly and seasonal successions in phytoplankton on a quantitative and qualitative basis.* 3- To determine the monthly and seasonal successional changes which might occur in the process of Aufwuchs colonization on artificial substrates . * * The investigation with reference to these two objectives was carried out from Oct.28, 1960 to June 11, 1961. Lama QQAiQIMQ SEUKWS REMARLY SAM PLED I- PLANKTON, OPEN WATER 0" .1600' n- PLANKTON, OPEN WATER 9,955; m-PLANKTON, OPEN WATER 9 A- Aurwucus. ARTIFICIAL SUBSTRATES \ B' AUFWUCHS, ARTIFICIAL SUBSTRATES C' SHORE AREA D'SHORE AREA INCIDENTALLY SAMPLED ®® @ (9 LAKE LANSING (5) © 6) AREA 452.5 ACRES INGHAM COUNTY T.4N..R.IW..$EC.2,3.IOJI Redrawn from a map supplied by the Institute for Fisheries Research Michigan Conservation Department. II. _T_‘_H_E_ LAKE A. Location and Immediate Surroundings Lake Lansing, formerly known as Pine Lake, is located approximate- Ly three and one-half miles northeast of the city of East Lansing and immediately north of the town of Haslett. It lies in Meridian township in the county of Ingham (TNN, R1W} Sects. 2.3.10 and 11). Because it is the largest body of water in that immediate area, the lake has played an important part in the recreational activities of the surrounding commu— nities. Its shore area is one of extensive resort development, with the accompanying number of septic tanks which empty into the lake. Rapidly aging, the lake contains a prolific abundance of floating, emergent, and submergent aquatic vegetation. Because of this the value of the lake as a recreational site has decreased and accordingly the residents of the area have undertaken a campaign to remove or control the nuisance vegetation. Both chemical and physical treatments have been applied;these it is certain will change the biotic composition of the lake. B. General Physical Characteristics The lake occupies an area of “52.5 acres, with the long axis of the lake running northwest-southeast for a distance of slightly more than one mile. The maximum width of the lake is about 5,000 feet, this being along an axis running east and west in the northern half; The depth of the lake, at the thme of this investigation, gradually increased from its shallow margin to a maximum depth of 37 feet. However, with a recent dredging in certain areas, this gradual slope has been changed to a sharp drop. There are two centers of relatively great depth. One occurs at the northwestern sector at 37 feet, the other is slightly west of the median line, at the southern tip, at a depth of approximately 27 feet. The average depth of the lake is 8.5 feet. (See map on page 3 for all locations.) The lake is a seepage one and apparently is spring- fed. There are no major streams which empty into it. There are two small inlets one at the southern tip the other at the north eastern sector, both of which are intermittent. The outlet is a small stream at the northwest; a dam is also located here. This dam.raises the level of the lake three feet. A thermocline occurs between 18 and 28 feet (Ball 1938), and was present until late August according to Tucker (1957). The bottom materials in general are composed of highly organic peat and marl. The shoal area is mostly fibrous peat while the deeper water is mostly pulpy peat. The depth of the peat and marl is variable but may be as much as ten feet or more (Michigan Associates 1960). Sand also occurs, mostly in scattered areas along the northern end of the lake.1 C. General Chemical Characteristics It is well known that organisms differ in respect to their nutrient requirements. Hence variations in the chemical composition of water help to determine the composition of the aquatic biota. In this study it was necessary to obtain analyses of water in an effort to understand rela— tionships between the algal flora and limnological features. 1The information regarding the physical characteristics of the lake, were obtained from Ball (1938), Tucker (1957), and Michigan Associates-(1960), also from calculations made from maps. The lake is a hardwater, alkaline lake, having a pH which ranges from 7.0 to 8.4 . In general it could be said that the pH tends to be more nearly neutral (7.0) along the swampy margins, and to be more alkaline (8.h) toward the center of the lake. Total hardness ranges from 152 to 164 ppm; alkalinity from 152 to 174 ppm; iron from .04 to .05 ppm; phosphates were in amounts lower than could be recorded on the instrument available to this investigator but in recordable amounts when tested by other workers (Tucker and Michigan Associates); nitrites from 0.004 to 0.007 ppm and nitrates from 0.135 to 0.27 ppm.2 (See table VII on page '73.) There is a high concentration of nutrients in the polluted areas where septic tanks empty into the lake. The differences between chemistry of the waters of these regions, in the marginal swampy regions, and in the open water of the lake, most assuredly are related to the dynamics of the community. Michigan Associates (1960), have made both chemical and biological analyses of the lake water, and the results are shown on table VI on page 72. D. Position and Description 93.392 Stations Regularly Sampled Stations The established or selected stations, I, II, III, A, B, C, and D, were visited regularly. They were marked either by permanent floats in the open water, or sited by land markers on the shore. (See map on page 3 .) Station I_is in the open water of the southern half of the lake, marked by permanent floats, approximately 900 feet from the west shore and about 700 feet from the east shore. The water at this point is 2The figures given above are solely in reference to the samples studied over the specific time indicated on table VII, page . between 15 and 20 feet deep, with no visible aquatic vegetation growing in the immediate area. The bottom material is of sand and some fibrous organic peat. Station I; is also in the open water but in the northeastern portion of the lake. It is approximately 800 feet from the north shore and directly south of the County Park. The water in this area is shallow being a little over six feet in depth. The bottom material is sand and supports a sparse submerged vegetation composed mainly of species of Potamogeton and Myriophyllum. Station III is another open water station, marked by permanent floats. It is about 900 feet east of the west shore, in the northwestern portion of the lake. The water in this area is between 20 and 25 feet deep, and there are no aquatic plants. Station‘§_ is located at the exact site of station I. This station is the site of placement of artificial substrates used in the study of Aufwuchs colonization. Station.§_ is located at the exact site of station III. This station is the site of placement of a second series of artificial substrates used in the study of Aufwuchs colonization. Station Q. is near the north shore, at the County Park. The water is shallow, the depth gradually increasing from 0 to 5 feet. The bottom material is sand, and on the beach there is practically no vegetation. East of station C is an area of aquatic vegetation, composed mainly of Potamogeton crispus, P. pectinatus, P. Richardsonii, Alisma plantago- gguatica, Ceratophyllum demersum, Myriophyllum gp., Scirpus validus and ‘ghggg sp. In this sector of the shore there is an intermittent spring which empties into the lake. West of station C the aquatic vegetation is sparse, being mostly Scigpu . Station Q_ is located near the west shore, directly south of the amusement park. The lake bottom slopes gradually from 0 to 5 feet. Recently the lake has been dredged in this area altering this depth. The bottom material is marl and the aquatic vegetation consists mainly of ghggglgp., several species of Potamogeton and Myrigphyllum. Septic tanks directly empty into the lake at this station. This is a site where residents have attempted to eradicate the nuisance vegetation, as previously mentioned. Incidentally Sampled Stations Stations 1 through 8 are those which were not visited regularly throughout the year. As incidental collecting areas, they provided a variety of habitats located at points around the lake which differed from those of the open water. Stations 1 and g are in swampy areas directly south of station D. The lake bottom slopes gradually in this area, from its bog-like margin. The bottom material is composed of fibrous peat. The higher aquatic vegetation is very dense, composed mostly of Typha latifolia, ygphgr'gggggg, Potamogeton Richardsonii and Myriophyllum sp. Station 3_ is located at the inlet at the southern tip of the lake in a swampy area similar to that of stations 1 and 2, but the aquatic vegetation is more extensive. Typhg latifolia, Nuphar advena, and Pontederia cordata are the most abundant species. Station 3 is along the east Shore at the southern portion of the lake. The aquatic vegetation in this area is not as great as that found at stations 1 through 3 but the region has a wide bog-like margin in ' which are found I£i§_§p. and Sarracenia.pugpurea. Nuphar advena is common along the shore. The bottom material is fibrous peat. Station 5 is in a small cove along the eastern shore. The water is shallow gradually increasing in depth from 0 to 4 feet. The bottom material is of sand and peat, and the aquatic vegetation is mostly Potamogeton americana, Nuphar advena, Pontederia cordata, Myriophyllum g2. , and S_cirpus validus. Station 6_ is located at Sunset Cove, east of Station C. The water is very shallow, from 0 to 4 feet deep. The bottom material changes from silty sand, to peat, to marl southward along the shore. The aquatic vegetation is not great in quantity but that which is present is mostly'ghggg §E°v Potamoggton pectinatus, E. Richardsonii, P. crigpus, P. americana and Myriophyllum sp. Station 2 is along the north shore to the west of station C. The bottem material is sand to the east, toward station C, and marl toward the west along the shore. There are a few septic tanks which empty into the lake near this station, and the lake shore is stony. The aquatic vegetation is sparse, mainly Scirpus validus. Station 8 is located at the outlet of the lake in the north—west sector. The water is approximately 6 feet deep, dropping rather rapidly from the Shore. The bottom material is fibrous peat and the vegetation is mostly submerged species of Potamogeton. III. METHODS AND MATERIALS The stations, just discussed and located on the map of Lake Lansing, met the requirements of the primary objectives of this investigation. They varied in condition or position from deep, open water to shallow open water, and from swampy areas with dense vegetation to clear areas with sparse vegetation. Collections were made at weekly intervals, depending upon the objectives related to the particular station. Weather conditions determined the regularity of the collections. The study was conducted over a period of two years, 1959 to 1960 and 1960 to 1961, excluding the summer months of July and August. The methods and materials used to obtain the biological, chemical, and physical data were deter— mined after a preliminary survey of the lake, and or were adapted from those recommended by Welch in "Limnological Methods", and in Standard Methods of Water Analysis 1960. A. Biological Techniques Euplankton Qualitative Euplankton qualitative samples were obtained from stations I, II, III, C and D, with incidental samples taken from the open water areas adjacent to stations 1 through 7. All samples were taken from the upper two feet of water. Two collecting methods were employed: (1) a No. 25 silk bolting cloth net, towed behind a boat, or cast out by hand; and (2) a Kemmerer Sampler (1200 cc capacity). (See quantitative euplankton techniques.) All samples were appropriately labeled, the labels indicating the area from which the sample was taken, with a code determined as follows: 10 11 If the plankton net had been towed from station I to station II, a distance approximately 3,200 feet, the label was written I - II. If the net had been towed from station D to station I, and then towed further in the direction of station II, for a distance of 1,600 feet, the label would read, D - I — IA, the total distance covered. (See map on page 3 .) Over 100 euplankton qualitative samples were made from Lake Lansing during the entire period of the study. After examination the samples were numbered and preserved in either 6—3—1, a solution consisting of water, alcohol and formalin, or Lactofenol Cuprico de Amann, for later reexam- ination. Microscopic mounts were made from each collection until no additional species were found. Camera lucida drawings were made, and measurements recorded, for all algal taxa. Euplankton Quantitative The procedures used for the quantitative determination of phyto- plankton, consisted of: (1) collecting the sample; (2) concentration and preservation of the sample; and (3) examination, enumeration and calcula- tion of the number of organisms per liter. The samples were collected from October, 1960 to June 1961 at the time intervals indicated on graphs 2, 3, 5, and 7. All the samples were taken at stations I and III, which are at opposite ends of the lake, from the upper two feet of water and before noon on the same day. Sampling was also undertaken at stations II, to see how this station differed from station III, which is at the same end of the lake but in deeper water. The sampling of this latter station for euplankton quanti- tative data was discontinued after a four-month study period. Sampling during the period of open water was accomplished from a boat and, during the period of ice cover, through a hole chopped in the ice. A Kemmerer Sampler was used for collections. This instrument is so designed, that samples may be taken from a desired depth, with a minimum amount of disturbance of the plankton. The operation of this instrument is discussed in welch (1948) and is quite simple. A two—liter sample was obtained and this was placed in a specially prepared two-liter glass container (carefully cleaned with distilled water and appropriate— ly marked for the particular station). Chloroform was immediately added to the sample, to slow down the activity of the organisms, until pre— servative could be added (Lactofenol Cuprico de Amann). The sample was then immediately transported to the laboratory for concentration. A Foerst Electric Centrifuge was used to concentrate the two—liter sample. (See welch, 1948, and Standard Methods of water Analysis,1960.) The centrifuge was set up as recommended but with a slight modification. This consisted of introducing a glass tube into the sample container. Through the tube distilled water could be passed, to wash down the walls of the sample bottle. It was believed this would give, in the long run, more accurate results. Ordinarily the apparatus consists of: the centrifuge, a funnel with an attached pinch-cock, and a ring stand with iron rings. to support the sample bottle. The sample bottle is inverted over the funnel which acts as a feeder into the centrifuge. The pinch— cock controls the delivery of water which is collected for a second operation. With the centrifuge running at a maximum speed of 20,000 r.p.m. the sample was fed through at a rate of one liter per eight minutes. The plankton was carefully removed from the centrifuge bowl, the bowl rinsed with distilled.water, and the sample volume increased to 20 ml. with preservative. 13 The Palmer Slide was used for phytoplankton counting. This slide has a volume of 0.1 ml. when filled and covered with a cover-glass, and is so designed that a #3X or 45X (high dry) objective can be used when viewing the slide. This allows for greater magnification and easier identification of organisms compared to the Sedgwick Rafter Cell (Palmer and Maloney 195h). Along with this slide, a Whipple reticule plankton- counting eyepiece, and a calibrated monocular compound microscope were used. The procedures for calibration and enumeration of nannoplankton were adapted from those suggested by Jackson and Williams (1962), while the use of'the counting slide itself was adapted from Palmer and Maloney (1954). Before placing the representative sample of the concentrate on the slide, the concentrate was thoroughly mixed. A total of 20 fields per sample were counted and the identification and enumerations of organisms were recorded on sheets similar to the forms shown on pages 14,15. A.sample of the calculations made to determine the multiplier factor, and the subsequent determination of the number of phytoplankton organisms per liter is presented on page 16 . 14 RECORDS OF EXNMINATION MICROSCOPICAL EXAMINATION sample NOOICOOOOCOOOOO0.0.0.000....SourceOOOOOO0.0000IOOOOOOOOOOOOOO... Date Of COllection. O O O O O O O O O 0 O O O O I .Date Of mamination. O O O 0 O O I O O O O I O O I O Conected by. I O O O O C I O O O O 0 O O O O O O O O O O Examined by. 0 O O O O O O O O O O O O O O O O O O O O 0 O O concentration...OOOOIOOOOOOOOOOIOOOt0.0.0...OOOOOTOtal wmtOOOOOOOOOOO NUMBER OF ORGANISMS Total Average ORGANISMS Total Count of fields . 3 5 7 q u n 15 :7 11 11691012141011» Count No. 15 ALGAL PLANKTON RECORD Locality Station No. Date Hr. Type of analysis (Meso—, Micro-, Nanno-) Organisms Number per field Total Average Diatoms Greens Blue-Greens Pigmented flagellates Tbtal Algae Unpigmented forms Tbtal organisms Pseudoplankton Grand Total INFORMATION BY COLLECTOR: INFORMATION BY EXAMINER: 1. Collected by 1. Analyzed by 2. Depth 2. Date 3. volume of sample 3. Method of concentration h. Preservative 4. Amt. of water concentrated 5. weather 5. Amt. of concentrate 6. Visible algal growth 6. Concentration 7. Type of counting cell 8. Magnification used 9. Area of microscopic field 10. Factor for No. per ml. Sample Computation Two—liter sample concentrated to 20 ml. Calculation of Multiplier Factor The total volume represented in the 20 fields examined consists of the total area of the Whipple fields multiplied by the depth. Vblume = (side of the Whipple field)2 x depth x No. of fields counted At a magnification of 440 x, it was observed that one side of the Whipple field.measures 0.230 mm. The depth of the Palmer slide is 0.4mm. The volume of the fields examined will thus be: v = 0.23 x 0.23 x 0.4 x 20 = .4232 mm.3 3 Multiplier Factor F = {fig—fig = 2363 2363 represents the number of times the volume studied would be contained in 1 ml. or 1000 mm.3 Calculation of Number of Organisms per Liter. No. of organisms ml. of concentrate in sample studied x 1000 ml. x 2363 x ml. of original sample Tychoplankton Qualitative The tychoplankton samples were collected from stations C, D, 1, 2, 3, 4, 5, 6, and 7. Collections from one or two or'more stations were made during almost all visits to the lake. Over 150 tychoplankton samples were collected, using a No. 25 silk bolting cloth net. Although the primary objective was to sample the free floating organisms, often the vegetation of the littoral region was squeezed, with the ensuing liquid collected into a vial. All samples were preserved and appropriate- ly labeled. Camera lucida drawings were made and.measurements for all algal taxa were recorded. 16 Aufwuchs Qualitative The Aufwuchs community includes all the organisms that are attached to, or move upon submersed substrates but which do not penetrate into it Reid (1961). With this definition in mind, it can be stated then, that all stations except II, were sampled to obtain Aufwuchs evaluations. At stations 1 through 8, representative samples of the visible algae were collected from stones, rocks, etc.; these were examined, and for the majority of the algal taxa, measurements and camera lucida drawings ‘were made. As mentioned previously, one of the primary objectives of this investigation was to record the monthly and seasonal successional changes which might occur in the process of AufWuchs colonization of artificial substrates. For this purpose two stations, A.and B, were equipped with appropriate equipment, which it was believed would yield such information. The equipment consisted of slide racks suspended at different levels in the open water of the lake. (See Welch 1948 and Cooke 1956 for discussion of the use of similar equipment in the study of attached organisms.) The racks were approximately seven inches long, three and one-quarter inches high, and one and one-half inches deep. They held 23 slides, which could be removed easily by sliding the upper and lower moveable arms out of the way. These arms could also be locked in place so that the slides did not fall out. (See figure one on page 20.) At station .A , the racks, suspended so that the slides were in a vertical position, numbered 1 through 4 , with number one being closest to the surface of the lake(1% feet below the surface). Between rack No.1 and 2, and 2 and 3, the distance was three feet. Between rack No. 3 and rack No. 4, the distance was 4 % feet. This would mean that rack No. 4 was 12 feet below the surface of the lake. At station B, the racks, l7 18 were suspended from floats (as were the racks at station A), and numbered one through three, with rack 1 again being 1 % feet below the surface of the lake, and the distance between rack No. 1 and 2 and between 2 and 3, being five feet. The collections on slides were made throughout most of the winter and spring until the equipment was taken from the lake by some unknown party. After the slides were removed they were transported to the laboratory for examination. They were preserved as whole mount slides, each being labeled with the date they were removed. A record of the time during which the slides were suspended in the lake was also kept. The slides were used to give qualitative information on the Aufwuchs _ community and were not originally intended to give quantitative infor— mation. However, it was obvious to this investigator, that the quantity of Aanuchs on the substrates differed depending upon the level at which the slides had been suspended and upon the time of the year the slides were introduced into the environment. An attempt was made to evaluate the difference in accumulation. This was done by placing the slides under the microscope, adding a Whipple ocular micrometer, and counting the number of organisms present in 20 separate fields the combined areas of which equaled 3 sq. mm. From the data obtained graph No. 8 was made. 19 Figure 1. Equipment used in the study of Aufwuchs coloniza- tion of artificial substrates. A. diagrmnatic representa- tion of slide racks at station A. B. slide racks at station B. C. plastic carrier used in transporting glass slides. D, illustration of Aufwuchs slide rack. fl—M-_A-Q——-—_-__-u—‘—‘-——.-——-—_~.—**—d-WF \ .5... 3ft. 1 3ft. 1 4.. 2 ijjlmmuml J' A f1. FIGURE - I “it”? fife. 5 f1. 1; 5ft. 1 63C B. P ical _a_n_c_1_ Chemical Techniques The physical and chemical data cited in this thesis were obtained from reports by Ball (1938), Tucker (1957) and Michigan Associates (1960) and from analyses made by myself. Regular sampling points were establish— ed at stations I, II and III. Water was collected from the upper two feet at the surface, using a Kamnerer Sampler as previously described. Surface water temperatures were obtained with a Centigrade thermometer graduated from -10 degrees to 110 degrees with an accuracy in reading of 0.5 degrees. Also recorded were the limit of visibility, the time of day, weather conditions (clear, cloudy etc.). and the water conditions (calm or rough). Total hardness, calcium hardness, and total alkalinity were obtained by using Hach titration methods, these being similar to methods suggested by Standard Methods of Water Annalysis (1960). The remainder of the chemical determinations, iron, nitrites, nitrates, phosphates, pH and turbidity as well were made by using a Hach DR. Colorimeter No. 585.* * Hach Chemical Compaxw Ames Iowa. IV. DATA AND MEASLILIMMTS 22 23 IN THREE HABITATS AU FWUCHS VLAHdOSAHHO 'ONVAO 'OHO'IHO ARTIFICIAL SUBSTRATES E E E a? '0N31ena AAA AAAAAA--- ViAHdOHHHAd AAAAAAAAAA /;q VIAHdOSAHHO Z(~ (. AAA VLAHdONVAO LIMNETIC " v 'v v w ’ \ .\’~ VIAHdOHO'I HO ‘\ 3%gi, leHeoua19n3 AA AAA AAA AAAAAAMAAAAAAAWA ' h g VLAHdOHMHAd PERCENTAGE OF EACH ALGAL DIVISION OCCURRING VlAHdOSAHI-IO LITTORAL VlAHdO NVAO VLAHdOHO'I HO GRAPH " I (IO 132999.32ng 24 AVERAGE SEASONAL VARIATION OF THE TOTAL PHYTOPLANKTON GRAPH'Z PERCENT COMPOSITION 00000100100 100 o Qqqthhwmggvvgqggggm m I:I:I:I:I:I:I:I:I 2: 53 " I.- MAY __ . - . . - . 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I III! - 1|[1llll'lil 1 ll fl 68 on m swampoc wsmcopooam m map ow: gmmgfip .2 mosmaw maven m Hapmsmdn .A awnmzpmom mhnmgbq magaxwe .um> msca .o mSmp mav .o . msoo apoccmw mounph< mfiamcwonao .< . m 30ng .oz xomm < d IOHHdam H .cmu .ooo .>oz mmpmnpmnsm Hmoamaph< :o mnoszmz¢ pcommum n * mo mafia... 23333 98.3203 > 3.5 69 ....w.................. 842.8 omaavmmfivom . mag. ****_.._.._.. .msnfico 0 .mm flnmcuse .m oumadmca ssnpmmsm mfivaua> xdunpopmxmam mmvoacmmflosno whommaa mHHonaamm memOOHUGAHho adamauoovsmma .o supmcmpm .o omcovmcmo.um> 09m .0 . m maanSOanuo ovomaoom gahomaaasoe aswnmpmoau A.uovcav owoomyonaopmmno Hacsmpm mso pom «Hummomoqmo N a N P N F a N F N w .02 xomm m < m < m 20Ha«am .08 .>oz 6.00 mmpwupmnbm Hmoamaph< co msoszas< pcomoum n * mo naming... 8333.5 385208 > «38. . mwocfipmamw whommmppme EBBWEp.e §§d58.9 .mm manoco :ognmmpuoe .am swocoaoomwwpm gpmcpo 33> mmnoomnmsv sspvwwusmpm . m m i * * “hmaoohnom map m * * § * * i * * * i * * * § * * * * i * mvzwo * mfi Qfiu.m maemovmcmom mappmp .m Hapahomn .pmb afip mpcfl.m O 7 xw n .02 xomm movwnvmnvm H¢0fiMd¢h< co mnoszafi¢ pzommum n * no mfimhamq< m>apmpaamso Aconcapzoov > magma D ATA PHYSICAL 8c CHEMICAL 71 72 Table VI Bacteriological and Chemical analysis made by the Michigan Department of Health DETERMINATION SAMPLE 1 SAMPLE 2 SAMPLE 3 SAMPLE 4 PPM ppm ppm ppm Phosphates 2.0 35.0 .0 .0 Free Ammonia as Nitrogen 3.5 14.0 1.2 .5 Potassium 2.8 6.0 1.8 .8 Nitrates as Nitrogen .2 .0 .0 .0 Detergent .6 7.0 .0 .0 Calcium Carbonate 28A 300 128 222 Hardness 305 275 140 250 pH 7.0 7.2 8.4 7.2 MPN 15,000* 1,h00,000* #30 36 BOD - 85 - - * Dangerous water for swimming is classified as having at least 2,400 coliform index. The surface water samples used above were obtained from the following points around the lake: Near inlet drain at south end of lake. (Corresponds to station 3.) Sample 1- Sample 2- Sample 3- Sample 4- Near shore at the end of the street near amusement park. (Corresponds to station D) Approximately center of lake. At the mouth of Clawson Drain on the north side of the lake. (In the area of station 6.) 73 Table VII Chemical analysis of surface waters of Lake Lansing. water samples taken at weekly intervals over a period of two months (Oct. and Nov.). The figures indicate a range. __DEIEEMIRAIIQN Station I Station II Station III PH 7-3 - 7.9 7-3 - 8.2 7.3 - 7-5 Total Hardness 152 - 158 ppm 154 — 160 ppm 156 - 164 ppm Alkalinity 154 - 174 ppm 152 - 170 ppm 152 — 162 ppm Iron .04 - .05 ppm .04 — .05 ppm .04 - .05 ppm Nitrates 0.135 — 0.26 ppm 0.135 — 0.27 ppm 0.175 - 0.21 ppm Nitrites 0.004 - 0.006ppm 0.004 .. 0.006ppm 0.004 .. 0.007ppm Turbidity 1.0 - 2.0 ppm 1.0 — 3.0 ppm 2.0 — 6.3 ppm V. DISCUSSION Lake Lansing. as are many other natural habitats, is a tremen— dously complex entity of multiple communities which respond and inter- act individually and collectively to each other as well as to the environment. To identify these communities, in reference to the objec— tives of this investigation, we can classify them on an ecological basis. in the following two ways: First according to occurrence. A. Limnetic zone; that region of open water the horizontal extent of which is bounded peripherially by the zone of emergent vegetation. B— Littoral zone; that region immediately adjacent to the shore, extending lakeward to the limit of occupancy of rooted vegetation. C— Benthic zone; that zone consisting of the lake bottom. (In this investigation it includes the Aufwuchs community.) Secondly, on the basis of the organism's life habitat. A. Neuston; organisms resting or swimming on the surface. asso- ciated.with the surface film. 8- Plankton; floating organisms unable to swim against currents, drifting. 1- Euplankton: true plankton; open water, drifting organisms. 2- Tychoplankton: floating or free-living organisms in shallow water of a lake intermingled with miscellaneous vegetation, usually near shore (Prescott 1962). C— Nekton; organisms capable of swimming against water currents. 74 75 D— Benthos; organisms attached on the bottom of an aquatic habi- tat; often considered in a limited sense as deep—water life. E. Aufwuchs; microorganisms forming a film and attached to, or moving upon submerged substrates (can be classified with Benthos). A combination of the above classifications has been used by this investigator, and as such, the regions of the lake and the community or organisms which inhabit them, are now treated individually. The limits designating these ecological groupings are not applied strictly since the organisms are dynamic and can transcend, or be displaced from one region to the next. Algal Communities Limnetic This open water community extending to the periphery of the zone of emergent vegetation and vertically to the depth of effective light penetration. is inhabited by organisms classified as euplanktonic. Intermingled with these, however. may be algae which usually inhabit the littoral and or benthic zones (including Aufwuchs). These are phy- sically transported into the region by currents or by locomotion of the organisms. The composition of the community may become modified, therefore for reasons other'than variations in limnological factors, and exclusive of time. Qualitative Analysis This series of analyses were undertaken to detenmine the degree of contribution made by the respective algal divisions to the limnetic community. 76 Qualitatively. of the 312 total algal taxa reported for Lake Lansing. almost half (164) were found occurring as members of the lim- netic community, representing several divisions of algae (Cyanophyta. Chlorophyta. Chrysophyta, Pyrrhophyta. and Euglenophyta). Of this number only 58 were found to occur strictly as euplanktonic. The re- mainder were found to inhabit as well, the tychoplankton of the littoral region and or the Aufwuchs community of the benthic zone. The total euplanktonic flora is composed of Chlorophyta 53.3 percent, Cyanophyta 36.4 percent, and Chrysophyta 10.3 percent. Although the green algae contribute the greatest number of taxa this does not imply that this group dominates the community quantitatively. The relative importance of the various divisions can be determined by comparing the number of taxa in each division present in the community. with corresponding figures for the entire lake. Of the total number of reported Chloro- phyta in the lake 44.3 percent occurred in the euplankton and only 20.8 percent of the total were exclusively euplanktonic. 0f the total Cyanophyta. 77.2 percent occurred in the euplankton. and 26.58 percent appeared exclusively in this community. The Chrysophyta are more diffi— cult to evaluate qualitatively, since the diatoms were not all identi- fied to species. Nevertheless, the importance of this division is quite evident when one analyzes the quantitative data presented previously and treated further on in the discussion. The ChrySOphyta are repre- sented in the euplankton by 69.7 percent of the total taxa of golden- brown algae, and 18.2 percent were strictly euplanktonic. It becomes evident, from the above data. that the Cyanophyta play their greatest role as members of the limnetic community, and that 50 percent of the Chrysophyta also occur in this community. Whereas the Chlorophyta 77 contributed the greatest number of taxa to the community. they are of secondary importance to the above divisions, and their major contribu— tion is to the communities of the littoral and benthic zones. The Pyrrhophyta and Englenophyta had no organisms which were strictly euplanktonic but of the six Dinoflagellate species, five occurred in the euplankton, whereas only eight members of the Euglenophyta, of a total of 45 taxa, were found occurring in this habitat. (See Graph No.1 for the above mentioned figures.) Quantitative Analysis Numerous publications on quantitative phytoplankton analyses exist in the literature, Birge and Juday (1922), Chandler (1940), Dailey (1938). Riley (1940) etc. Most workers agree that in medium to large sized, deep lakes of the temperate zone, phytoplankton communities exhibit an annual population curve. in respect to numbers of individuals. which is bimodal in character. Such a curve expresses a large spring pulse followed by a decrease in the p0pulation during the summer, with a second smaller pulse occurring in the autumn Odum (1959), Pennak (1946), and Welch (1952). Smaller, shallower lakes, however, eaduibit population curves which can be highly variable, with no pulses or with one, two or three pulses, occurring at various intervals throughout the year as shown by Pennak (1946 and 1949). The data obtained from the present investigation, illustrated on Graphs 2 through 7, clearly indicate the weekly and monthly variations in the population. The spring maximum. mentioned previously as being typical of certain lakes in the temperate zone, is clearly revealed. No autumn.maximum is indicated, however, as the investigation did not cover the time period when this autumn.pulse might occur. Tucker (1957), in his quantitative phytoplankton study of 78 Lake Lansing from August to early November, did not indicate any autumn pulse. Fluctuations in the community composition, based on the algal divisions present are shown on Graphs 3, 4, 5, 6, and 7, while the percent composition, of the total phyt0plankton present, represented by each division, is indicated on Graph 2. It is revealed from these data that, in the order of numerical abundance (unlike the qualitative analysis) the most important contributors to the limetic community are the Chrysophyta, Cyanophyta, Chlorophyta, and Pyrrhophyta. In general, stations I and III, exhibited equal trends in the fluctuations of the phytoplankton p0pulation, and although the species compositions differred in the two areas, the species responsible for the major trends, including the spring maximum, were the same. The re- sultsof the investigation, beginning in late October at both stations, indicated a decreasing number of organisms until the middle of November. During this time the Cyanophyta were the most abundant organisms (48 percent) but the Chrysophyta were almost equal in numbers (45 percent). The remaining 7 percent represented the Chlorophyta. From about the middle of November until late January, the population showed a definite increase in numbers to what could be considered a small midawinter pulse. This pulse was attributable to the Chrysophyta. and more speci- fically to the diatom Synedralgp. and to Dinobgyon sociale. Synedra was most abundant during the early phases of this pulse but at its peak, Dinobgzon sociale was dominant. The CyanOphyta were completely absent at the end of November, and the Chlorophyta, represented primarily by Scenedesmus quadricauda, persisted in small quantities until the end of January. The population reached its minimal point in early March, with the phytoplankton at this time, entirely composed of Chrysophyta. 79 Dinongon sociale was the dominant species at station I. and Synedra, accompanied this Species at station III. There was a decided increase in the phytoplankton population, culminating in the spring maximum in late April, following the melting of the ice cover in mid-March. The organisms responsible for this spring pulse, were the same as those which contributed to the midawinter'pulse. At the peak, or shortly thereafter, however. all the previously mentioned algal divisions were present (Chrysophyta, Cyanophyta, Chlorophyta, and PyrrhOphyta). The spring max- imum was followed by a population decrease through May and June, and the ChrySOphyta, which had previously composed the total or major portion of the total phytoplankton, were at a minimal condition. The Cyanophyta contributed the largest number of organisms in late May and June, exhib- iting a pulse of its own during this time. From this time on the Chloro- phyta and PyrrhOphyta showed gradual increases as the season progressed, while the blue—greens and golden-brown algae, were on the decrease. (See Graphs 2, 3, 5, and 7 for all the above mentioned fluctuations, and Tables II, III, and IV for the complete quantitative data on individ- ual organisms.) Station II, located in shallow water, as opposed to the other stations located in deep water, revealed a parallel fluctuation in the phytoplankton population until late November. As the season progressed, however, with colder temperatures and subsequent formation of an ice cover, the population exhibited a marked decrease. This was in direct contrast to what was occurring at the deep-water stations (development of midpwinter pulse). The species composition did not differ to any appreciable extent from that occurring at the other stations, and in actuality, the organisms composing the major portion of the phytoplankton 80 were the same. According to the chemical and physical data taken, (Table VII), it appears that there were no differences which would account for the exhibited contrasting condition. However, not all the test performed were at a level which could indicate sensitive differences (phosphates), or concerned with other elements essential to the popula- tion such as oxygen and carbon dioxide. Under such conditions two things appear plausible and related. First, the population decrease is obviously related to the biolog— ical condition of the community. That is, the mortality rate of the organisms exceeds the natality. This is an expression of the reaction between the organisms comprising the population the physical and chemical nature of the environment; the actions and interactions of and between the organisms as well as other inhabitants of the community; and upon the individual life histories of the population components. Of the first and last operatives, with reference to their influence from the available data, little more can be said. The second operative could in affect be responsible for the decrease in the population with various biological factors coming into play: antibiotic inhibition of a species to itself and other organisms, inter and intra species competition, and animal grazing to mention a few such biological factors. Of a speculative nature, self inhibition of the population caused by antagonistic sub— stances arising from the metabolism of the phytoplankton, seems plausible. Fluctuations in the total phytoplankton number, caused by self inhibi- tion, is known (Rice 1954). Secondly, it appears that the above factors have a greater affect upon the community when operating under conditions in which the environ— ment is in some way restricted. Under conditions of shallowness, where 81 inhibitory substances are not diluted as much as they would be in greater water depth, these substances would be in greater concentration and as such would have a greater affect upon the community. Further, the effects of antagonistic substances upon the biota would be related to the re— strictions imposed by ice cover. water movement is inhibited and the concentration of solutes is increased when ice forms. The period of ice cover endures at a time of year when productivity is low and when other limitations are operating (low incidence of light e.g.). The Chrysophyta contributed the greatest number of organsims throughout the four-month study period with the Chlorophyta contributing the second largest number. The Cyanophyta were represented in but small numbers and the Pyrrhophyta not at all in quantitative analyses. (See Graph No. 7 and Table No. IV, for comparison of total phytoplankton present, composition by algal division, and complete quantitative data for individual organisms.) water Blooms ‘Water blooms, a conspicuous and abundant growth of planktonic algae, sometimes appear suddenly, and often form a surface scum (Prescott 1962), in the lake. However, none were recorded at any of the stations where quantitative samples were collected. Often the blooms accumulate along the shore areas, as a result of wind and wave action. Four separate water blooms were observed during this investigation. The first, occurring in the fall of 1959, turned the surface waters of the shallow littoral region a pea soup color, and was composed primarily of Microcystis aeruginosa, M. flos-aquae, Coelosphaerium Naegelianum, and Anabaena sp. These same organisms then formed a similar bloom in the fall of 1962. 82 Ceratium hirundinella was the cause of a bloom in the spring of 1960 in the area along station C, coloring the water a redish—brown. Also observed at this time, was an abundance of dead fish. Whether the two events are related can be only conjectured. However, some of the Pyrrhophyta are known to be the causitive agents in fish-kill (Graham.1951). In this area and east and west of station C, in the fall of 1960, the fourth and largest bloom was observed. This was caused by Tolypothrix Egguis occurring in scattered patches which extended lakeward five to ten feet and for variable distances along the shore. In some areas this Tolypothrix bloom was from one to two feet in depth and the area appeared a deep bluish-brown. All these blooms, although perhaps originally members of the limnetic community, eventually became components of the littoral zone, and as such, influenced the algal community in this area both directly and indirectly. 83 Conclusions 1— The limnetic community is inhabited by organisms classified as euplanktonic. Intermingled with these, occur algae which usually inhabit the littoral and or the Aufwuchs community. 2— Almost half of the taxa reported for the entire lake can be found occurring as members of the limnetic community, and they represent- ed all the major divisions of algae: Clorophyta, CyanOphyta, Chrysophyta, Pyrrhophyta and Euglenophyta. 3- The Chlorophyta contributed the greatest number of taxa to the limnetic community. 4- The Chrysophyta contributed the greatest quantity of organisms to the limnetic community. In order of numerical abundance the Chryso- phyta are followed by the Cyanophyta, Chlorophyta, and Pyrrhophyta. 5— The Pyrrhophyta and Euglenophyta are the only divisions which have no taxa exclusively found as member of the limnetic community. 6— The limnetic community exhibited considerable weekly, monthly and seasonal variation both qualitatively and quantitatively. 7- Although the quantitative data available does not indicate an autumn pulse, a small mid-winter pulse in January, and a large spring pulse in April was clearly indicated for the phytoplankton community of this region. The population reached a minimal point in early March. 8— The exhibited fluctuation in the total phytoplankton is a reflection of the individual fluctuations of the organisms which form the community. 84 9— Principal organisms in the fall belong to the divisions, Cyanophyta and Chrysophyta; in January to the Chrysophyta and Chloro- phyta; in March to the Chrysophyta; in April to the Chrysophyta, Chlorophyta and Cyanophyta; in late April to the Chrysophyta, Chloro- phyta, Cyanophyta, and Pyrrhophyta; in May and June to the Cyanophyta and Chlorophyta with a minimal amount of Chrysophyta. 10- Parallel fluctuations in the phytoplankton exist between wide— ly separated areas. A significant exception existed in a region of shallow water under ice cover. 11— Synedra and Dinobgyon sociale are the principal taxa during the winter and spring pulses. 12— Water blooms, conspicuous and abundant growths of planktonic algae, occur in the lake. The organisms forming such blooms were Microcystis aeruginosa, M. flos-aguae, Coelosphaerium Naegelianum, Anabaena gp., Ceratium hirundinella and Tblypothrix tenuis. 13~ The investigation of the limnetic region, although indicating that there are fluctuations and differences in community composition, especially with reference to time, also indicates that there is much uniformity in composition with reference to space. The exhibited unity of character is a result of the degree of homogeneity of the environ- ment, (or habitat), in this instance the open water. Littoral The littoral region is immediately adjacent to the shore, and extends lakeward to the limit of the rooted vegetation zone. In this investigation, however, only that portion up to the zone of floating leaf vegetation, has been investigated. In contrast with the more homo— geneous environment of the limnetic, the littoral is highly heterogene- ous. Various biological. chemical and physical forces combine to form a number of varying environmental conditions, resulting in the forma— tion of particular habitats with recognizable communities. Responsible fOr this diversification in habitats and.the delimiting of their communities are such factors as: the influence of the open water, non-homogeneous composition of the lake bottom, higher aquatic vegeta— tion, wind and wave action, concentration of dissolved substances (i.e. nutrients) from decomposing organic matter, inorganic matter, indirect effect of effective light penetration, and fluctuations in the water level. Using the previously cited classification, the com- munities are those of the plankton (tychoplankton) and those of the Aufwuchs. Along with the tychoplanktonic organisms exclusively located in these waters are also included many forms occurring in the limnetic community as well as some displaced from the Aufwuchs. The Aufwuchs can be further classified according to the substrates. There are communities on inorganic substrates (stones, rocks, etc.) and there are those on organic substrates (living higher aquatic vegetation etc.). The community developing on the usually transient higher aquatic plant is composed of forms which are quick—growing with short developmental 85 86 cycles. Whereas the inhabitants of the more permanent inorganic or, long-existing organic substrates (i.e. sunken logs), are those forms which are slow-growing with longer developmental cycles capable of forming persistent or permanent colonies. The investigation revealed that the littoral region has the greatest variety of organisms and this is not surprising since it is the most heterogeneous environment in respect to critical factors. Of the 312 taxa reported for the lake, 237 or 75.9 percent can be found in this region, and these figures represent all the major divisions of algae. Whereas the Cyanophyta make their greatest contribution to the limnetic community, the Chlorophyta, Euglenophyta, Chrysophyta, and Pyrrhophyta are more abundant in the littoral zone. (See Graph No. 1.) The flora here was composed of Chlorophyta 45.6 percent: Cyanophyta, 21.5 percent; Euglenophyta,19 percent; Chrysophyta’11.3 percent and Pyrrhophyta,2.6 percent. The major portion of the total number present, (93.7 percent), can be found in the plankton. Plankton The tychoplankton, especially rich in organisms which are found strictly in this habitat (over 50 percent) also includes organisms displaced from the Aufwuchs and limnetic communities. The Euglenophyta and Pyrrhophyta, by their very nature, are mostly planktonic, and as such, are represented in the region by all species reported as occurring in the lake. It should be noted however: that whereas 80 percent of the Euglenophyta are restricted to the littoral region where waters are rich in organic nutrients, the Pyrrhophyta are not so restricted. 87 Although all members of the Pyrrhophyta occur in the littoral region, 83.3 percent of the taxa also occurs in the limnetic community. (See Graph No.1.) Only one Species, Peridinium pipes, was found to be restricted to the littoral plankton. Members of the Euglenophyta found to occur in the littoral plankton only are: Euglena acus Phacus pleuronectes E. omris var. minor 2. pseudoswirenkgi Phacus ankylonaton _P. rudicula g. contortus var. cmlicatus P. setosus _P_. gigas g. tortus _P_. lismorensis P. undulatus g. longicauda var. insects P. Eguis _P_. orbicularis fa. £0 Elatalea Eight other Phggus were recorded as members of the plankton of the littoral region but they were not identified to species. 'me remain- ing Euglenophyta found exclusively in the zone were: Lepocinclis ovum Trachelomonas planctonica Trachelomonas australica var. oblonga var. rectangularis T. pulcherrima _T_. bulla f _T. splendidissima '_I'_. gvlindrica _'1_‘. volvocina _T_. hispida var. $131335 3. volvocingpsis _T. obovata var. klebsiana var. punctata Anisonana _s'p. 88 The Cyanophyta are represented primarily by true, free-floating organisms, or intermingled with other algae to form masses. Of the 51 blue-green taxa reported occurring in the littoral region 46 were found in the tychoplankton. However, of these 46 taxa, only six appear to be true plankters of this region: Chroococcus varius, Merismopedia punctata, Aphanothece stagnina, Oscillatoria amoena, Anabaena catenula, and Aphanizomenon flos-aquae. The remaining 40 taxa include seven which were found exclusively in the littoral community but occurred in inter- mingled algal masses: Oscillatoria sancta, Phormidium subfuscum, gzggbya Lagenheimii, L. Nordgaardii, Scytonema crispus, ngalosiph n _p. and Microcoleus lacustris; one species Plectonema nostocorum which inhabits the mucilage of Aphanothece stagnina, and the remainder are organisms which were common to the littoral, limnetic and or the Aufwuchs community. The Chrysophyta are very well represented in the plankton. How- ever, the majority of these organisms (diatoms) have been displaced from the Aufwuchs community, or can also be found in the limnetic. There are only six species which appear to be restricted to the region in the form of true plankters or as intermingled masses: gphioqytium 213.125.; Tribonema bombycinum, I. utriculosum, _T_. 33323 and Vaucheria geminata. This latter species often forms tangled mats almost on the shore. Besides the diatoms, Dinobryon cylindricum and.D. sertularia are common to both the plankton of the littoral and of the limnetic regions. The Chlorophyta represent 43.1 percent of the total algal taxa present in the littoral plankton, and 60 percent of these are found exclusively in this habitat. The major portion of these taxa are desmids, and they occur along the quiet margins of the lake. [lllllllll'lill‘i‘lll 89 Penium margarita ceum Pl eurotaenium trabecula Micrasterias s01 Closterium acerosum _C_2_l._. acerosum var. tumidum 9;. incurvum _C_Z_L_. leibleinii 91. pseudolunula g. strigosum _C_l_. sublaterale Staurastrum Brebissonii _S__t. disputatum fl. granule sum it. J ohnsonii §_t_. polymorphum _S_t. punctulatum fl. Sebaldii var. ornatum S3. striolatum Cosmarium anggosum 9. Bot is _g. Botmis var. mediolaeve Q. constrictum Cosmarium cucumis _q. 10 In In lo lo 10 In In In lo 10 lo I O O O O O O O O O O 0 IO 0 K: _g. cymatoplerum var. tyrolicum formulosum imam impressulum 13233 var. depressum We ochthodes pachyde mum pseudoornatum pseudopyramidatum regnesii reniforme subcostatum subtumidum sulcatum var. sumatranum tetraophthalmum Tugpinii vexatum vexatum var. rotundatum Wittro ckii Ungerianum Five other desmids were collected but not identified to species. Other green algae found occurring exclusively in the plankton of the littoral region are: 90 Chlamydomonas pseudopertyi Nephrocytium Agardhianum Pandorina m N. mum Chlorosarcina consociata Microgora tumidula Pediastrum biradiatum M. Willeana Schizomeris Leiblinii Ulothrix tenerrima Tetraedron trigonum var. gracile Frequently tangled among the higher aquatic plants, dense mats of mixed algae occur in the littoral region. The mats are composed primarily of filamentous green algae, most frequently displaced from the Aufwuchs community. They vary in composition but the taxa usually composing the masses are: Spirogyra porticalis, S. singularis, _S_. spp. Mougeotia spp., Oedogonium spp., Ulothrix spp., Cladophora insignis, _g. m, g. glomerata, Rhizoclonium crassipellitum, Zygnema sterile, and _z. spp. Sometimes glindrocapsa geminella may also occur. The mats often break apart allowing the component species to become more loosely associated with true plankton organisms. Aufwuchs The Aufwuchs is "That community of organisms that is attached to, or move upon, a sutmersed substrate, but which do not penetrate into it. " Reid (1961). As pointed out previously, these Aufwuchs communities transcend into all the regions of the lake, although some authorities consider it part of the benthos Cooke (1956). Although Seligo, 1905, is credited with being the first to use the tem Aufvmchs designating organisms attached to but not penetrating a substratum. as sited by Young (1945), and Cooke (1956), the term was not and is not the only one used. Hentshell 1915, used the term Bewuchs, and both these terms 91 were used together Willer (1929), Lenz (1928) and separately, Ruttner (1952), depending upon the investigator, in either narrower, broader, or in a completely different sense, than the original authors used them. The term periphyton was and is used by many investigators, Newcombe (1949), Young (1945), Cooke (1956), Roll (1939), Grzenda (1960). However, this term was originally used by Behning, 1924, to designate only organisms growing on artificial objects in water. Today the term has been expanded to mean: "That assemblage of organisms growing upon free surfaces of sub- merged objects in water, and covering them with a slimy coat. It is that slippery brown or green layer usually found adhering to the surface of’water plants, wood, stones or certain other objects immersed in water and.may gradually develop from a few tiny gelatinous plants to culminate in a woolly felted coat that may be slippery or crusty with contained marl or sand. " Young (1946), Welch (1948). As one can see the terminology has been expanded until one can become confused as to what another investigator'may mean when he refers to Aufwuchs, periphyton, etc. My study of this community could in part come under the original meaning of periphyton , as used by Behning, but I have not used the term for any portion of my investigation because its latter use has been expanded in.meaning so that it is not readily distinguishable from Aufwuchs. Since the latter is the older term and really broader, I believe it is the more preferable one to use. I would like to emphasize two points concerned with this investi- gation. First. the investigation if this community is cocerned solely with the algal composition, and secondly, primarily with growth that occurs on artificial substrates provided by the investigator, and upon persistent inorganic substrates (stones etc.) or the more resistant organic substrates (pilings etc.). The investigation of the Aufwuchs on living and non-living aquatic plants, was carried on by another investigator, Dr. Sebastian A. Guarrera of Universidad de La Plata, and Will be reported on in a subsequent publication in the future. For an exhaustive review of the literature on Aufwuchs see Cooke (1956) and Sladeckova (1962). The Aufwuchs community of the littoral region is composed of species belonging to the mrySOphyta, Chlorophyta, and Cyanophyta, and of the 237 taxa reported for the littoral region, 17.8 percent can be found occurring as members of this community. These figures are,in a way, misleading, for the Aufwuchs is far richer in the number of taxa present. However, the diatoms, which are the greatest contributors to this community were not identified to species, which accounts for the low percentage indicated above. One fact seems apparent as one views Aufwuchs communities growing on inorganic and organic substrates. The community on the inorganic substrate, stones, rocks. etc., is thick, firm, dark, and usually is slippery. 0n the other hand, the community on living substrates is usually light, fluffy, and flocculent. These appearances are due to the species composition of the communities on the different substrates. The communities on stones are primarily composed of diatoms, and lake- 'ward the diatoms become more and more the dominant algal constituent. As one collects stones closer to the shore, more of the filamentous green algae become apparent. Stones closer to the shore, (besides the diatoms), were typically inhabited by: Stigeoclonium lubricum, §, temgig, and various species of Oedogonium. These have the appearance of cottony 93 masses or feathery tufts. Draparnaldia glomerata and species of Cladophora are other members of the Aufwuchs community on inorganic substrates and the latter genus often appears like flowing, long, green hair. Upon the suhnerged persistent organic substrates. Stigeoclonium flage_11iferum occurs, and especially in the quiet waters of the swampy regions Tetraspora gelatinosa is often present. Caloth_ri_x parietina, a blue-green, was collected as a member of the Aufwuchs community. However, the substrate was piling. in the center of the lake and so not a component of the littoral region. It is men- tioned here because it will not be considered with any of the remaining communities to be discussed. his investigator collected a few samples of the visible algae growing on the higher aquatic plants. The flocculent material was at various times, mixtures of green, blue-green, and golden-brown algae, and included the following taxa: Oedogonium globosum, 9.. Pringsheimii, Q. spp., Bulbochaete sp. Qghio_cy‘_timn desertum, _q. gracilipes, Calothrix wonanicola, 9; M, _C_. Castellii, Q. Braunii, and Phomidium tenue. Conclusions The following statements can be made concerning the littoral region. 1- With its great heterogeneous envirorment created by various biological, chemical and physical factors (i.e. non homogeneous com- position of the lake bottm, higher aquatic vegetation, wind and wave action, concentration of dissolved substances, etc. ) the littoral region supports the largest variety of organisms present in the lake. 2— There are 312 taxa reported for the entire lake, and 237 occur in the littoral region with 95.8 of these being found in the plankton. 3- More of the Chrysophyta, Chlorophyta, Euglenophyta, and Pyrrho- phyta can be found in the littoral region than in other zones in the lake. 4- The communities are those of the plankton and those of the Aufwuchs. the latter community can be further classified into those communities on inorganic substrates and those on organic substrates. 5- The plankton is not only rich in the number of organisms exclusively found in this region but also abundant in organisms dis— placed from the Aufwuchs and limnetic communities. 6- All taxa of the Euglenophyta.and Pyrrhophyta are found occurr— ing in the littoral plankton, with 80 percent of the Euglenophyta restricted to these waters, rich in organic nutrients. 7— The Cyanophyta primarily are present in the littoral region as members of the plankton. 94 95 8- The Chrysophyta are primarily part of the AufWuchs community but.most of the taxa can also be found in the plankton as a result of being displaced from its former community. 9- The Chlorophyta represent over 40 percent of the littoral plankton and the major portion of these are desmids located in the quiet, margin waters. 10- Mixtures of filamentous green algae frequently occur floating or tangled among the higher aquatic vegetation. 11- The Aufwuchs community on organic substrates differs in appearance from.that on inorganic substrates. The community on stones, rocks, etc. is dark, thick, firm.and usually slippery. That on the higher aquatic plant life is light, fluffy and floculent. 12— The diatoms are the dominant constituents of the community on stones etc., whereas the filamentous Chlorophyta and various Cyanophyta, compose the major portion of the floculent community on the higher aquatic vegetation. Aufwuchs 2g Artificial Substrates Investigation of the initiation and development of the Aufwuchs on artificial substrates (glass slides) revealed that the diatoms were not only the pioneer organisms but the persistent basic constituents of this community. Whereas it has been pointed out previously how the Aufwuchs greatly conributed to the plankton community of the limnetic region, it will now become apparent that the planktonic forms of the limnetic community contribute significantly to the Aufwuchs. It only need be mentioned that the initial population of the substrates origin- ates from the plankton. Qualitatively the Chrysophyta, Chlorophyta and Cyanophyta are responsible for the community composition. The percentages of these divisions present, as compared to those present in the entire lake are Chrysophyta 51 percent, Chlorophyta 18 percent, and Cyanophyta 19 percent. (See Graph No. 1 for the above mentioned percentages Graph No. 8 and Table No V, for all qualitative and quantitative data on this community.) Examination of the AufWuchs composition on the slides after only seven days exposure indicated that the following genera of diatoms were the first to become attached: Diatoma, Amphora, Cocconies, gymbella. Fragilaria, Acnanthes, and Synedra. These same genera, although showing individual fluctuations, were usually in abundance throughout the study period and formed the basic diatom component of the community. Even with this basic diatom composition, the community still exhibited seasonal variation, and this was especially related to the plankton community. Planktonic organisms (eu- and tychoplankton), such as desmids 96 97 were caught and held in the tangle of the attached forms, so that the AufWuchs composition depended greatly upon what organisms were present in the plankton at the time the substrates were placed in the environ- ment. Related to this, is the fact that there was also a difference in the vertical distribution of the organisms, so that the particular site where the racks‘were placed would also influence the community composition. With the introduction of the glass slides in October, besides the above mentioned taxa were included in.the Aufwuchs: Anabaena sp., Oscillatoria tenuis. Scenedesmus bijuga and S. quadricauda. As the community developed through November and December, the composition became more complex with the addition of the following taxa: Chroococcus sp., 9. turgidus, 9. dispersus,‘yyngbya Diguettii, Plectonema notatum, Chaetophoraceae (indet.), Elakatothrix viridis, Oedogonium Sp., Pediastrum Boryanum. P. intergrum var. perforatum fa., and Scenedesmus dimorphus. New slide substrates introduced in November and December did not contain the previously mentioned Anabaena sp. This genus was also absent during this time from the plankton community. During January there were no additions of blue—greens but two, Chroococcus dispersus and.§. turgidus were absent. Since the blue-greens did not appear in the surface plankton of the limnetic community after November, it appears that certain of the planktonic blue-greens occur for a longer period of time, as members of the Aufwuchs community. The green algae, which were present in the plankton until late January and then reappeared in March, were still present in the Aufwuchs community. There was an increase in the number of Chlorophyta taxa, and there were only three taxa, two filamentous (Oedogonium and Chaetophoraceae) and one planktonic alga, 98 (Scenedesmus dimorphus), which were no longer constituents of the community. The new taxa present were: Cosmarium sp., 9. granatum, Euastrum insulare, E. Turneri fa., Oocystis sp., Pediastrum tetras, Staurastrum qgebecense var. ornatum, and Tetraedron minimum. Unfortunately the Aufwuchs samples for February were not obtained, because the slides were removed from the racks, by some unknown party. The colonization and development of the Aufwuchs community through March and April is quite dramatic. All but four of the taxa (Pediastrmn tetras, Staurastrum.ggebecense var. ornatum, Oocystis sp. and Tetraedron minimum), present in January, compose the community. In April the community reached its most heterogeneous composition. Many of the former blue-green and green algae, present during the early phases of this investigation, reappeared. So that along with those still present from January, were the following taxa: Anabaena circinalis Closterium moniliferum Arthrospira Jenneri Cesmarium angulare var. canadense Chroococcus turgidus vars maximus Cosmarium pseudoornatum Iyngbya aestuarii Cylindrocapsa geminella ‘yyggbyg Diggetii Dispora crucigeniodes Merismopedia glauca Oedogonium sp. Microcystis aeruginosa Pediastrum duplex Oscillatoria tgngig §phaerocystis Schroeteri Plectonema notatum Stigeoclonium sp. §pirulina.princeps TEtraedron enorme fa. Chaetophoraceae (indet.) Tetraedron trigonum In May and June, examination of the community indicated a decrease in the number of taxa present. No longer contributing to the composition were the following: Anabaena circinalis Cylindrocapsa geminella _Chroococcus turgidus var.maximus Euastrum insulare Microcystis aeruginosa Tetraedron enorme fa. Cosmarium granatum Tetraedron trigonum Cosnarium pseudoornatum Two taxa previously present, reappeared and there were five taxa not previously recorded, present in the community: Botryococcus Braunii Tetraspora gelatinosa Coleochaete orbicularis Spirulina subsalsa Scenedesmus dimoxphus MerismoPedia tenuissima Spirogra sp. Anabaena sp. Changes in composition brought about by menbers of the Chrysophyta throughout the investigation, have not as yet been mentioned. This is because the changes were not easily detected and for the most part were very gradual. There were some taxa which appeared rather suddenly or sporadically but the division, represented primarily by the diatoms, was well-distributed throughout the study period. Cymatoplgra, appears only from April to June, and only on the substrates closest to the surface. Dinobryon sp., appeared twice, once in November at the lowest depths, and then again in April on the substrates closest to the surface. Eithemia was present only in January and April and Gomphonema became attached in January and persisted until May, appearing on all substrates except those closest to the surface. Nitzschia was recorded only during April and May occurring at the lower levels. Pinnularia and Rhopalodia, appeared sporadically throughout the investigation, and only in May and June, on the surface racks. Ophiocytium cochleare was present only in April. 100 It is seen from the above information, that as the season pro- gressed the composition of the Aufwuchs community changed, becoming most complex during March and April. The rate of development of the community was also variable, not only with reference to time but also with reference to space. When comparison is made of the amount of accumulated Aufwuchs, on substrates introduced into the environment at various intervals but for equal lengths of exposure time, it is indicated that the community exhibited population pulses like those occurring in the plankton. For example, slides introduced at the end of December, develop- ed an Aufwuchs in January, far greater in numbers, than slides intro- duced in October, November and early December, over an equal length of time. Substrates examined in late January had less than those in early January. Slides introduced in late March had accumulated Aufwuchs in April, greater than at any other time during the investigation, as shown by comparison with slides introduced at other times of the year, and exposed for the same length of time. With reference to space. it was noticed that the amount of Aufwuchs differed in quantity, depending upon the level at which the substrates were located (the exposure time at each level being equal). Graph No.8 was made to show this variation, using the method previously described on page 18 . This graph (station A) indicates that as the community begins its development, the greatest quantity of Aufwuchs occurs on the substrates nearest the surface. As the community progresses, however, the accumula- tion of Aufuchs is greatest at the second (4 % feet below the surface) and at the third level, (7 % feet below the surface), and usually most- ly at the latter rack. In April the graph indicates that Rack No. 1 .. L}.‘lll‘ll)lllnlillll ‘llll-Il‘l I IlI‘ll'll'lIlIII-lll 101 once again had an abundant Aufwuchs development. I believe this is a direct result of the influence of the plankton. Recall that during this same period, the surface waters were exhibiting the spring plankton maximum. In June the graph indicates that there was a sharp drop in the quantity of Aufwuchs at Rack No. 3. Examination of the slides at this level indicated that the substrates were covered with aquatic animals, which appears to indicate a condition of predation. Before discussing the quantitative development of the community at station B, it should be mentioned that the racks here received a great deal of disturbance by fishermen, and were finally taken from the lake by some unknown party. In November the racks had been completely removed from the water and replaced because some of the slides were missing. Whether this would account for the sporadic amount of develop- ment at the various levels, can only be guessed. In December Rack No. 1 was taken from the lake. The remaining substrates at the other two levels indicated that the greatest quantity of Aufwuchs occurred at level No. 2, (this level is almost equal in depth to level No. 3, at station A). In January the quantitative relationship between levels No. 2 and 3, is the same as that in December. The graph in March,indicates that there was a sharp drop in the quantity of AufWuchs at level No. 2. At the time the slides were examined the substrates were covered with an aquatic fungus. In general, Aufwuchs development was similar in composition at station A and B but station A.had a greater quanity for an equal length of exposure time. l [I I! l {I lllll‘rllll‘! Li‘. Ill! _Illlllll'. t‘li III. I (1 ‘III I ..llll ‘III I ‘ {Ital I. 1 1‘ [I'll Conclusions The following conclusions can be made from this study: 1- The use of vertically placed slides at various levels in a lake, is very useful for studying the development and composition of the Aufwuchs community. 2— Placing the substrates in a vertical, as opposed to a horizontal position, still allows for the attachment of living organisms, and lessens the chance of organic detritus settling upon the substrate. 3- Removal of the Aufwuchs from the substrate, while lifting the racks from the water, once the community is established, is not readily done. 4h The original population of the substrates originates from the immediately surrounding plankton. 5. The rate of develOpment and the complex succession of taxa, involved in the formation of the AufWuchs community, is related to a number of variables i.e. time (month, year), space (vertical etc.). and the orgaisms present in the region. 6- The Aufwuchs exhibits fluctuations in the rate of increase in the number of individuals similar to that exhibited by the plankton, i.e. with a small mid-winter pulse and a spring maximum. 7- The Aufwuchs community is different both in quality and quantity at different levels. Whereas one might expect that substrates in the upper level would have a greater quantity of Aufwuchs because of the light factor, this is usually not the case. 102 103 8- At any particular time the community is composed of a wide variety of algae, and along with these are animals and fungi, which can alter the quality and or the quantity of the community elements. 9- The major constituents of the community are the diatoms. 10- A significant number of planktonic taxa become incorporated into the Aufwuchs community. 104 . SUMMARI Lake Lansing, fonmerly known as Pine Lake, is located approximate— ly three and one-half miles north-east of the city of East Lansing, and bordering the northern limit of the town of Haslett. The present investi- gation was undertaken to contribute to the very inadequate knowledge of the algae in the lake, in respect to both species composition and community structure. The objectives therefore, were as follows: 1- To determine the floristic composition of the lake, and to record the types of habitats where particular algal papulations existed. 2— To determine the nature of monthly and seasonal successions in phytoplankton on a quantitative and qualitative basis. 3. To determine the monthly and seasonal successional changes, which.may occur in the process of AufWuchs colonization on artificial substrates. The lake occupies an area of 452.5 acres with the long axis running northwest-southeast for a distance of slightly more than one mile. Rapidly aging, the lake contains a prolific abundance of floating, emergent and submergent aquatic vegetation, which have greatly decreased the value of the lake as a recreational site. It is a hardwater, alkaline lake, having a pH tending to be more nearly neutral along the margin and to be more alkaline toward the center of the lake. There is a high concentration of nutrients in the polluted areas derived from the many septic tanks which empty into the lake, and from decomposition of abundant organic matter. 105 Five selected collecting stations were regularly visited and eight stations were incidentally sampled. These provided the variety of habitats needed for this investigation. All but six of the 312 taxa reported here as occurring in the lake were collected and determined. Of these 306 taxa, 13 are new records for Michigan or for North America. Fourteen taxa are listed as previously undescribed in the literature, and four are listed as pre— viously undescribed forms of known species. The algal communities of the lake are in the limnetic, littoral and the benthic regions. It was found that these regions are normally inhabited by associations of species in recognizable communities. These communities, however, definitely are not rigidly delimited, nor are their compositions static and fixed. They are entities which in response to their environmental surroundings are dynamic in composition, and they vary according to time and space. The limnetic community can be characterized by the following: 1- A community composed of euplanktonic organisms plus organisms displaced from the littoral and from the AufWuchs community. 2— Almost half of the number of taxa found occurring in the entire lake, contributes to the composition of the community, which exhibits considerable weekly, monthly and seasonal variation both qualitatively and quantitatively. A.midawinter and spring maxima were indicated. 3— In order of numerical abundance, the following algal divisions contribute the greatest quanity of organisms to the phytoplankton: Chrysophyta, Cyanophyta, Chlorophyta and Ryrrhophyta. The fluctuations in the total phytoplankton is an expression of the total affect of the individual fluctuations of the organisms 106 composing the community. Although the limnetic community fluctuates and differs in composition, especially with reference to time, the community also exhibits unity in composition with reference to space. The exhibited unity of character is a result of the degree of homogeneity of the environment. The littoral region is characterized by the following: 1- It contains the largest variety of organisms present in the lake. Of the 312 reported taxa, 237, can be found in the littoral region 2— The communities are composed of the plankton, in which 95.8 percent of the taxa of the region can be found, and the Aufwuchs. The Aufwuchs can be further divided into the communities on inorganic and organic substrates. 3- More of the taxa of the following algal divisions can be found occurring in the littoral region than in other zones of the lake: Chlorophyta, Chrysophyta, Euglenophyta and Pyrrhophyta. 4- The Euglenophyta and Pyrrhophyta are represented in the littoral plankton by all the taxa of these divisions which are reported to occur in the entire lake. 5- The plankton is not only rich in the number of taxa exclusive— ly found in this region (more than 50 percent) but also abundant in organisms displaced from the limnetic and or the Aufwuchs communities. 6- The Aufwuchs communities on inorganic and organic substrates differ in appearance and composition, the former being composed primari- ly of diatoms, the latter of filamentous Chlorophyta. The Aufwuchs community on artificial substrates, in this investi- gation, is considered part of the benthic community, and is characterized 107 by the following: 1- The initial population originates from the planktonic environment. 2— It contains mainly diatoms, with a considerable number of planktonic organisms becoming secondarily incorporated. 3- There were 62 taxa which composed the Aufwuchs community throughout the study period. The rate of development, and the complex succession of taxa, involved in the formation of the community, is related to a number of variables of which should be mentioned: time, three dimentional locality and the biota available at the particular region. Taking into consid— eration the interplay of migration, natality. etc. the rate of accumu- lation of the community is similar to that of the plankton community, with a small mid-winter pulse and a spring maximum. ll“ lt‘lt‘l'll}.ll‘l[t|l ll'llgrllll‘lltf‘?!‘ 1"; The date which follows each taxon in this list is the date in which the taxon was first published in the combination here used. Descriptions of these taxa may be found in the reference cited after each taxa. Division Cyanophyta Class Myxophyceae Sub—class A. Chroococceae Order Chroococcales Family Chroococcaceae Chroococcus Naegeli 1849 Chroococcus dispersus (Keissler) lemmermann 1904 ' Pl. 1_fig. 4 Prescott 1962, page 447. Diameter of cells 3 — 4.5/i. EMplankton: Station D. Aufwuchs: Artificial Substrates Station A. Chroococcus limneticus Lemmermann 1898 P1. _1_ fig. _11 - Prescott 1962, page 448. Diameter of cells 6 — 7.quwithout sheath. Euplankton: Station D. Chroococcus limneticus var. carneus (Chodat) Lemmermann 1904 Prescott 1962, page 448. Diameter of cells 8 — 9.0pvwithout sheath. Euplankton: Stations III4 - D. 108 109 Chroococcus limneticus var. distans G.M. Smith 1916 P1. 1 fig. 2 Smith 1920, page 30. Diameter of cells 6.48 - 7.0n.without sheath. Euplankton: Station D. Chroococcus limneticus var. subsalsus Lemmermann 1901 Pl. 1 fig. 3 Prescott 1962, page 449. Diameter of cells 3.24 — 4.86p.without sheath. Euplankton: Station C. Chroococcus minimus (Keissler) Lemmermann 1934 Prescott 1962, page 449. Diameter of cells 2.5 -3.gu without sheath.. Euplankton: Station C. Chroococcus minutus (Kuetz.) Naegeli 1849 Prescott 1962, page 449. Diameter of cells 4.86 - 6. 5,1,; without sheath. Euplankton: Stations D-I, II-C. Tychoplankton: Station 1. Chroococcus turgidus (Kuetz.) Naegeli 1849 P1. 1 fig. 2 Prescott 1962, page 450. Diameter of cells 14.0 - 22.0p.without sheath. Euplankton: Stations C,D, 114 — II — 1113, III - D - I, 5. Tychoplankton: Stations C,D,1,5. Aufwuchs: Artificial Substrates Station A. Chroococcus turgidus var. maximus N gaard 1926 P1. 1 fig. 1 HuberaPestalozzi 1938, page 14?. Diameter of cells 39.5 - 41.0p.without sheath. Euplankton: Station D. AufWuchs: Artificial Substrates Station A. 110 Chroococcus turgidus ? The cells are grouped in fours or eights, their diameter being from 9.72 - 12.0}L. The sheaths were wide and lamellated, colored a yellowish brown. The colonies of eight were from 38.0 — 45.0ptwide. This plant was collected twice, in both the euplankton and the tychoplankton. It differred from the typical by having colored sheaths. Station D. Chroococcus varius A. Braun in Rabenhorst 1861 — 1878 Pl. 1 fig. 19 Prescott 1962, page 451. Diameter of cells 5.0 — 6.0/4. This plant is larger than the typical species. Tychoplankton: Station D. Gloeocapsa Kuetzing 1843 Gloeocapsa puntata Naegeli 1849 Prescott 1962, page 452. Diameter of cells 1.62 — 2.4/L. Euplankton: Station C. Tychoplankton: Stations C,D. Aphanocapsa Naegeli 1849 Aphanocapsa elachista west & West 1895 P1. _2 fig. _6_ Prescott 1962, page 453. Diameter'of cells 1.62 — 2.0/1. Euplankton: Station C. Aphanocapsa pulchra (Kuetz.) Rabenhorst 1865 Prescott 1962, page 454. Diameter of cells 4.0 - 4.5/1. Euplankton: Stations II4 - II, III - D. 111 ALhanocagsa rivularis (Carm.) Rabenhorst 1865 P1. 3 fig. 8 Prescott 1962, page 454. Diameter of cells 6.0 - 6.5/1. Euplankton: Stations C,D,5, I - II4. Microcystis Kuetzing 1833 Microcystis aeruginosa Kuetzing anend Elenldn 1924 P1. _2 fig. _2 Prescott 1962, page 456. Diameter of cells 4.68 — 7.0/u. Euplankton: Stations D - I, I - II — C, II - III, 1.3. Tychoplankton: Stations C,D. Aufwuchs: Artificial Substrates Station A. Microsystis flos-aquae (Wittr.) Kirchner 1900 P1. 3 fig. 3 Smith 1920, page 39. Diameter of cells 3.5 - 5.25/4 . Euplankton: Stations C,D, D — I - II, II — III - D, 3,5. Tychoplankton : Stations C , D. Microgstis incerta Lemmermann 1903 P1. _2_ fig. _1 Prescott 1962, page 457. Diameter of cells 1.62 - 3.12/4. I followed Prescott, 1962, in assigning to g. incerta Lemm. foms listed by other authors under the name 3. pulverea (Wood) Migula. Euplankton: Stations I - II, D, 5. Merismopedia Meyen 1839 Mefiswefia convoluta de Brebisson in Kuetzing 1849 P1. _1 fig. _1_2_ Prescott 1962, page 458. Diameter of cells 3.5 - 4.0/u. Length of cells 5.25 - 7.0/L. Euplankton: Stations C,D. ’I‘ychoplankton : Stations C , D. 112 Ierismopedia elegans A. Braun in Kuetzing 1849 P1. 1 fig. 6 Prescott 1962, page 459. Diameter of cells 4.68 — 5.02/L. Length of cells 6.24 - 7.80/1. Euplankton: Stations C,D. Tychoplankton: Stations C,D. Merismopgdia glauca (Ehrenb.) Naegeli 1849 P1. _1_ fig. _7_ Prescott 1962, page 459. Diameter of cells 3.9 - 6.0/u. Euplankton: Stations C,D, II - C - III, I. TychOplankton: Stations C,D, 1,2. Aufwuchs: Artificial Substrates Station A. ierismopedia punctata Meyen 1839 P1. 1 fig. 8 Smith 1920, page 33. Diameter of cells 2.75 - 3.5;4. Tychoplankton: Stations C,D. Merismgpedia tenuissima Lemmermann 1898 Pl. 1 fig. 2 Smith 1920, page 33- Diameter of cells 1.40 — 2.34/1. Euplankton: Stations D - I, 114 - II, II - III. Tychoplankton: Stations C,D,5. Aufwuchs: Artificial Substrates Station A. Merismopedia Troleri Bachmann 1920 Prescott 1962, page 460. Diameter of cells 3.14 — 4.0/u. Euplankton: Station D. Tychoplankton: Station D. 113 Gloeothece Naegeli 1849 Gloeothece rupestris (lynb.) Bornet 1880 P1. 1_fig. ll Prescott 1962, page 462. Diameter of cells 4.05 — 6.48/L. Length of cells 11.34 - 12.0/1. Euplankton: Station D. TychOplankton: Station D. Rhabdodenma Schmidle & Lauterborn 1900 Rhabdoderma irregulare (Naumann) Geitler 1925 P1. 1 fig. g; Prescott 1962, page 463. Diameter of cells 1.4 _ 2.0/A. Length of cells 4.0 - 5.0/1. Euplankton: Stations D,5. Aphanothece Naegeli 1849 Aphanothece Castagnei (de Breb.) Rabenhorst 1865 P1. _2_ fig. _5_ Prescott 1962, page 467. Diameter of cells 3.24 .. 3.5/a . Length of cells 4.86 - 5.0/4. Euplankton: Stations C,D. Tychoplankton: Stations C,D,5. Aphanothece microscopica Naegeli 1849 Prescott 1962, page 468. Diameter of cells 3.5 - 4.0/1. Length of cells 5.0 - 6.8/4. Euplankton: Stations C,D, I - II4, II4 - II, II - III. 114 Aphanothece microspora (Menegh.)Rabenhorst 1863 P1. _2_ fig. _4 Prescott 1962, page 468. Diameter of cells 2.4 - 2.73/1. Length of cells 5.6? - 6.0/L. Ehplankton: Station C. Aphanothece nidulans P. Richter 1884 Prescott 1962, page 468. Diameter of cells 1.5 - 1.63/1. Length of cells 3.0 - 3.24/L. Ehplankton: Station D. Aphanothece saxicola Naegeli 1849 Prescott 1962, page 468. Diameter of cells 1.62 - 2.07/1. . Length of cells 4.86 - 5.0/l. Euplankton: Station C. Aphanothece stagnina (Spiengel) A. Braun in Rabenhorst 1864 — 69 P1. _2_ fig. 2 Prescott 1962, page 460. Diameter of cells 3.5 — 4.0/1. Length of cells 5.0 - 7.0/A. Free floating colonies: Stations C,D,2.4,5,6. CoeloSQhaerium Naegeli 1849 Coelosphaerium Kuetzingianum Naegeli 1849 P1. ; fig. 1g Prescott 1962, page 470. Diameter of cells 3.0 - 4.68/z. Diameter of colonies 62.0 - 71.76/4. Euplankton: Station D. Tychoplankton: Stations C,D. Coelospharium Naegelianum Unger 1854 P1. 1 fig. 12 Prescott 1962, page 470. Diameter of cells 3.0 — 3.5/t. 115 Length of cells 3.5 - 5.0/A. Euplankton: Stations C,D, I - II, III - III4. TychOplankton: Stations C,D. Marssoniella Lemmermann 1900 Marssoniella elegans Lemmermann 1900 P1. 2 fig. Z Prescott 1962, page 471. Diameter of cells 2.5 ... 3.12lu. Length of cells 6.24 - 7.0/1. Euplankton: Stations C,D, I - II4, II4 — II. Gomphosphaeria Kuetzing 1836 Gomphosphaeria aponina Kuetzing 1836 Smith 1920, page 37. Diameter of cells at greatest width, 4.5 - 5.5/1. Length of cells 7.5 - 9.0/1. Euplankton: Stations C, II. Tychoplankton: Stations C,D. Gomphogphaeria aponina var. cordiformis Wolle 1882 Smith 1920, page 37. Diameter’of cells at greatest width, 9.0 — 10.5/1. Length of cells 14.0 — 15.25/1. Diameter of colonies: 49.5 — 52.5/1. Euplankton: Station D. Gomphosphaeria aponina var. multiplex Nygaard 1926 P1.‘1 fig. 18 Huber-Pestalozzi 1938, page 152. Diameter of cells at greatest width, 7.5 - 8.0/1. Length of cells 14.0 - 15.5/1. Diameter of colony 56.0 - 63.0/1. Euplankton: Stations D - I, C, II, 5. Tychoplankton: Stations C,D. 116 Subclass B. Hormogoneae Order Hormogonales Suborder Homocystineae Family Oscillatoriaceae Spirulina Turpin 1827 Spirulina giggntea Schmidle 1902 Pl.'3 fig. 6 Desikachary 1959, page 197. Trichomes 3.24 — 4.guin diameter; spirals 11.0 — 12.48/Lbroad. Euplankton: StatiOns C,D. Tychoplankton: Stations C,D. Spirulina princeps (west & West) G.S. West 1907 P1. 3 fig. 11 Prescott 1962, page 480. Trichomes 4.26 — 5.0uin diameter; spirals 9.36 — 10.0/Lwide; distance between spirals 14.0 - 15.0/1. Euplankton: Stations D - I. Tychoplankton: Stations C,D. AufWuchs: Artificial Substrates Station A, Spirulina subsalsa Oersted 1842 Prescott 1962, page 480. Trichomes closely spiralled, 1.63 - 2.0/tin diameter; spirals 3.24 .. 3.5/1 wide. Euplankton: Stations D - I - II, III3 - III. Tychoplankton : Stations C , D. Aufwuchs: Artificial Substrates Station A. Arthrospira Stizenberg 1892 Arthrospira Jenneri Stizenb. ex Gomont 1852 P1. 2 fig. Z Desikachary 1959. page 192. Trichomes 4.0 - 5.0p.wide; cells 3.24 _ 4.q#.1ong; regularly spirally coiled; spirals 9.0 - 9.5ycwide; distance between spirals 12.96 - 13.77p.. 117 Euplankton: Stations D — I, II4 _ II - C - III, III - D, 3. Tychoplankton: Stations C,D,3,5. Aufwuchs: Artificial Substrates Station A. Oscillatoria Vaucher 1803 Oscillatoria amoena (Kuetz.) Gomont 1892 P1. 3 fig. 13 Prescott 1962, page 484. Trichomes 4.68 - 5.46p.in diameter; cells 3.0 — 3.12/Llong. Tychoplankton: Station D. Oscillatoria princgps vaucher 1803 P1. 3 fig. 8 Prescott 1962, page 489. Trichomes 38.88 - 40.0/Lin diameter; cells 4.86 - 5.qu,in length. Euplankton: Station C. Tychoplankton: Stations C,D. Oscillatoria sancta (Kuetz.) Gomont 1892 P1. 3 fig. 1_o_ Prescott 1962, page 490. Trichomes 15.72 - 17.16/Lin diameter; cells 3.12 — 4.0/tin length. Intermingled with other algae on submerged vegeatation. Station D. Oscillatoria subbrevis Schimdle 1901 Prescott 1962, page 491. Trichomes 5.5 - 6.0/4. in diameter; cells 1.26 .- 2.0/4 in length. Euplankton: Stations II4 — II. Tychoplankton: Stations C,5. Oscillatoria tenuis C.A. Agardh 1813 P1. 3 fig. 12 Prescott 1962, page 491. Trichomes 4.86 — 7.02/4 in diameter; cells 3.12 - 3. 24/4 in length. Euplankton: Stations C,D, I - II - III. Tychoplankton: Stations C,D,3. Aufwuchs: Artificial Substrates Stations A,B. I [I'll I (I‘ll {I I'll ‘l‘ [I II 118 Phormidium Kuetzing 1843 Phormidium subfuscum Kuetzing 1843 Prescott 1962, page 496. Trichomes 6.5 - 7.0u.in diameter; cells 2.0 — 2.5u.in length. Intermingled with other algae along shore. Station D. Phormidum tenue (Menegh.) Gomont 1892 Prescott 1962, page 496. Trichomes 1.5 — 2.5u.in diameter; cells 2.76 — 3.0a in length. On submerged vegetation along shore. Station D. Lyggbya Agardh 1824 gyngbya aerugineo-coerulea (Kuetz.) Gomont 1892 P1. 3 fig. 2 Desikachary 1959, page 315. Filaments 6.24 - 7.0/u. in diameter; Trichomes 5.46 .. 6.0/L in diameter; cells 2.0 - 2.34/Lin length. Intermingled with other algae in aquatic vegetation. Stations C,D. EMplankton: Station C. gyggbya aestuarii (Mert.) Liebmann 1841 P1. _4 fig. _1_ Desikachary 1959. Page 305. Filaments 12.48 - 13.0/Lin diameter; Trichomes 10.14 — ll/Lin diameter; cells 3.12 - 3.5/Lin length. Among aquatic vegetation: Stations C,D,5. Euplankton: Stations C,D — I, 5. Tychoplankton: Stations C,D. Aufwuchs: Artificial Substrates Station A. EXnEbKa Birgei G.M. Smith 1916 P1. g fig. ;9 Desikachary 1959. page 296. Filaments 19.44 - 20.0/Lin diameter; trichomes 16.0 - 17.5u.in 119 diameter; cells 2.34 - 2.5M.in length. Euplankton: Station D. Lyngbyaggiguetii Gomont 1895 P1.‘2 fig. 11 Desikachary 1959. page 310. Filaments 3.24 - 3.4u.in diameter; trichomes 2.02 - 2.43%,in diameter; cells 1.5 — 1.62/L in length. Among other algae: Stations C,D,3,5. Euplankton: Stations C,D. Aufwuchs: Artificial Substrates Stations A,B. Lyggbya Hieronymusii Lemmermann 1905 P1. 2 fig. 13 Prescott 1962, page 501. Filaments 12.96 - 13.5“.in diameter; trichomes 10.92 - 11.0u in diameter; cells 2.43 - 3.0u.in length. Euplankton: Stations C,D — I - II4, II2 - II, III - D, 3.5. Tychoplankton: Stations C,D,l. Lyngbya Lagerheimii (Moebius) Gomont 1890 P1. 4 fig. 3 Prescott 1962, page 501. Filaments 2.0 - 2.48/iin diameter; trichomes 2.2 — 2. 30/L in diameter; cells 2.43/Lin length. Intermingled with other algae: Station D. Lyggbya,fl§jgg Meneghini 1837 P1. 2 fig. 13 Prescott 1962, page 502. Filaments 16.38 - 21.64p.in diameter; trichomes 14.06 — 16.20u-in diameter; cells 2.34 - 3.24/Lin length. Euplankton: Stations C,D, D - I. Tychoplankton: Stations C,D. Intermingled with other algae: Stations C,D. Lyngbya Martensiana Meneghini 1837 P1. 4 fig. _4 Prescott 1962, page 502. Filaments 8.10 - 10.92/1. in diameter; trichomes 6.48 — 9.36}; in 120 diameter; cells 2.5 - 3.lp.in length. Euplankton: Stations C,C - III, 114 - II, D - I. Tychoplankton: Stations C,D. Lyggbya Nordgaardii Wills 1918 Prescott 1962, page 503. Filaments 1.62 - 2.0p.in diameter; trichomes 1.34 - 1.5M.in diameter; cells 1.2 - 1.3/Lin length. Among other algae along the shore: Station D. Microcoleus Desmazieres 1823 Microcoleus lggustris (Rab.) Farlow 1877 P1. 2 fig. 2 Prescott 1962, page 505. Filaments 35.5 - 37.0u.wide; trichomes 3.12 - 4.0u.in diameter; cells 4.68 - 6.24/,4 in length. Intermingled with other algae along the shore: Station D. Suborder Heterocystineae Family Nostocaceae Anabaena Bory 1822 Anabaena catenula (Kuetz.) Bornet & Flahault 1888 P1. 3 fig. 3 Huber-Pestalozzi 1938, page 215. Cells 6.48 - 8.10“ in diameter; heterocysts 6.48 — 8.5/Lin diameter; gonidia 8.10 - 9.72/1. in diameter, 25.0 — 27.54,; in length. Tychoplankton: Station 5. Anabaena circinalis Rabenhorst 1852 P1. 3 fig. 3 Huber—Pestalozzi 1938, page 214. Cell diameter 7.29 - 8.0/L; heterocysts 8.0 - 9.72/Lin diameter; gonidia 14.5 - 15.60/4 in diameter; 27.5 - 31.2/1. in length. Aufwuchs: Artificial Substrates Station A. Anabaena flos-aquae (Lyngb.) de Breb. 1836 Reported by Tucher (1957). Illll. l Ilill [Ill 1'“ III" l l 121 Anabaena macrospora var. robusta Lemmermann 1898 P1. 3 fig. 4 HuberaPestalozzi 1938, page 209. Cells 9.72 - 10.0p.in dimaeter; heterocysts 11.34 - 12.0p.in diameter; gonidia 17.84 - 18.0;Lin diameter; 32.76 _ 34.08fL in length. Euplankton: Stations C,D. Anabaena Schermetievi Elenkin 1909 P1. 3_fig. g Huber-Pestalozzi 1938, page 207. Cells 9.36 - 10ptin.diameter; heterocysts 9.2 - 9.5p.in diameter; gonidia 12.48 - 18.72p_in diameter; 18.72 - 19.5”.in length. This plant is very similar to var. incurvata fa. ovalispora Schkorbat. Euplankton: Station D. Anabaena subgylindrica Borge 1921 P1. 2 fig. 1 Huber-Pestalozzi 1938, page 210. Cells 3. 24 — 4.0» in diameter; 6.48 — 8.10/u in length; heterocysts 3.24 _ 3.5;:in diameter; gonidia 6.48 - 7.9u.in diameter; 50.2 - 56.70fltin length. The size of the vegetative cells of this plant, plus the fact that the gonidia can occur in a series, suggest that this plant is lg. gxlindrica Lemm., however the gonidia of 5. gylindrica do not exceed 30;4, and this plant clearly shows the gonidia A. subgylindrica; for this reason it is placed here. I suspect that these two species may be one, with two or more different morphological expressions. Euplankton: Station C. Anabaena sp. Not determinable due to lack of spores. vegetative cells 3.0 - 3.4;cin diameter; cells 2.43 — 2.5/Lin length; heterocysts 3.24 - 3.4;Lin.diameter; 6.48/Llong. Euplankton: Stations C,D, I. AufWuchs: Artificial Substrates Stations A,B. I {I ill-I'll. . [{ll" .. [ ‘II‘ I." ’1 l Ill 1‘ 1“ l. [Ill l I III II‘ 122 flgstgg Vaucher 1903 Nostoc paludosum Kuetzing ? Prescott 1962, page 524. Cells 3.2 - 4.6;Lin diameter; heterocysts ovate, 4.68u.in diameter; This plant placed here on the basis of size and habit. Euplankton: Stations C,D - I .. II4. TychOplankton: Stations D,4,5. Aphanizomenon Morren 1838 Aphanizomenon flos-aquae (L.) Ralfs 1850 Prescott 1962, page 528. Cells 5.5 -6.0}Lin.diameter; 7.85 — 9.0u.in length. Heteroqysts 7.0u.in diameter; 12.5 - 13.0;Llong. Tychoplankton: Station D. Family Scytonemataceae Sgytonema C.A. Aagardh 1824 qutonema crisppm (C.A.Ag.) Bornet 1889 P1. 4 fig. 7 Prescott 1962, page 535. Filaments 20.0 ~ 21.84ytin diameter; trichomes 14.04 - 15.0/tin diameter; cells 3.0 - 3.9;Lin length; heterocysts 17.16 - 18.9u. in diameter; 17.16/Llong. Intermingled with other algae: Station D. Tblxpothrix Kuetzing 1843 Tolxpothrix 1mmbata Thuret in Bornet & Flahault 1887 P1. 4 fig. 6 Prescott 1962, page 538. Filaments 9.72 - 10. 5min diameter; trichomes 5.67 - 6.48/Lin diameter; cells 4.5 -5.0ptin length; heterocysts 7.0 - 9.72/Lin diameter. Entangled among aquatic vegetation: Stations C,D,4,5. Free floating: Stations II - C. 123 Tolypothrix tenuis Kuetzing emend J. Schmidt 1899 P1. 4 fig. 8 Prescott 1962, page 538. Filaments 12.48 - 14.0» in diameter; trichomes 4.68 - 7.08,» in diameter; cell length 3.12 - 6.24/u; heterocysts 6.24 - 7.08}; in diameter; 8.0 - 12.48/u. long. Iam following J. Schmidt (1899), who included _T. Lanata in _1_‘. tenuis, when he redescribed the latter species. Water blooms covering stations: 0.6.7. Free floating: Stations II - III. D - I - II4. Tychoplankton: Stations C,D,1,6,7. Plectonana ‘eret 1875 Plectonema nostocorum Bomet 1880 Pl.4 fig. _1_9_ Prescott 1962, page 539. Filaments 1.5 - 2.0/.4. in diameter; cells 1.2 - 1. 5,11. in diameter; 1.42 - 2.0/u. long. Inhabiting the mucilage of Aphanothece stagnin . Plectonema notatum Schmidle 1902 Prescott 1962, page 540. Filaments 1.76 - 2.0,; in diameter; trichomes 1.2 .. 1.7,e1n diameter; cells 2. 5 - 3.0/along. Among other algae. Biplankton: Stations D - I, II - III - D, C, 5. Tychoplankton: Stations C,D,l,2,3,4,5,6,7,8. Aufwuchs: Artificial Substrates Station A. Family Stigonemataceae Hapalo siphon Naegeli 1849 Hapalo siphon sp. Prescott 1962, page 543. Filaments 6.48 - 7.0» in diameter; cells ovate 4.86 - 5.0/1. in diameter; Not enough material in the proper condition, seen. to identify the species. Intermingled with other algae along the shore: Station D. 124 Family Rivulariaceae Calothrix C.A.Agardh 1824 Calothrix Braunii Bornet 8: Flahault 1886 P1. 4 figs. _1_2: & _1_} Poljanski 1953. page 360. Filaments 9.36 — 10.92;; in diameter at the base; trichomes 6.24 .. 7.80;; in diameter; heterocysts 4.68 .- 6.24}1. in diameter. This plant had its sheaths colored a yellowish brown at the base, which is not characteristic for this species according to the description. However, Poljanski, mentions that the sheaths can rarely be colored. 0n submerged vegetation: Station C. Calothrix Castellii (Massa1.) Bornet 8: Flahault 1886 P1. _4 fig. 14 Geitler 1932. page 611. Filaments 10.92 - 12.0}; in diameter at the base; trichomes 8.58 .- 9.0}.t in diameter at the base, and 4.68 - 5.0/L at the mid-region. Heterocysts 8.21 - 8.5,u. in diameter, 6. 24 - 6.5,». long. Attached to the mucilage of Tetraspora. Calothrix fusca (Kuetz.) Bornet a Flahault 1886 P1. .4 fig. _1_l_ Geitler 1932, page 610. Filaments 10.4 - 12.0,; in diameter at the base; trichomes 7.80 .. 8.1,u. in diameter at the base; cells 3.12 - 3. S/u. long at the base; heterocysts 7.8 — 8.9uin diameter. Attached to the mucilage or in the mucilage of other algae. Stations C,D,2,3. Calothrix parietina (Naeg.) Thuret 1875 P1. _4 fig. 2 Geitler 1932, page 605. Filaments 9.36 - 10/4 in diameter at the base; trichomes 7.8 — 8.0,“ in diameter at the base; cells 2. 5 - 3.12/u long at the base; heterocysts 6.24 - 6. 5/u. in diameter. On pilings near Station I. I‘lllfl’l‘l il‘li.ll1‘l!:lil til! 125 Calothrix mtonemicola Tilden 1910 P1. _4 fig. 5 Tilden 1910, page 265. Filaments 8.10 - 8. 5p. in diameter at the base; trichomes at the base 7.5 - 8.0/u. in diameter; heterocysts 8.10/u. in diameter. On submerged vegetation: Station 5. Division Qirysophyta Class Xanthophyceae Order Heterococcales Family chlorotheciaceae Ohiocytium Naegeli 1849 Qghiogtium cochleare (Eichw.) A.Braun 1855 P1. 5 fig. 4 Pascher in Rabenhorst's Kryptogamen Flora Vol. XI Heterokonten 1939. page 887. Cells 7.80 - 8. 58,}. in diameter. TychOplankton: Stations 0,5. Aufwuchs: Artificial Substrates Station A. Qphiocytium desertum Printz 1914 P1. 5 fig. 2 Pascher in Rabenhorst's Kryptogamen Flora Vbl. XI Heterokonten 1939, page 905. Cells 10.92 - 12.0}; in diameter; 48.36 - 51.48,“ long. Attached to aquatic vegetation: Stations 4,5. @hiocytium gracilipes Rabenhorst 1868 P1. 5 fig. _6 Pascher in Rabenhorst's Kryptogamen Flora. Vbl. XI Heterokonten 1939, page 901. Cells 7.80 - 8.0/min diameter; 45.24 — 47.0}; in length. Attached, epiphytic upon other algae; Station 1.5. Ophiocytium majus Naegeli 1849 P1. 5 fig. 5 Prescott 1962, page 365. Cells 15.60 - 18.72,» in diameter; 260.30 - 569.10/u in length. Tychoplankton: Stations 3,4,5. 126 Order Heterotrichales Family Tribonemataceae Tribonema Derbes & Solier 1856 Tribonema bombycinum (C.A.Ag.) Derbes & Solier 1856 P1. _5_ fig. 2 Prescott 1962. page 367. Filaments 6.48 - 8.10% in diameter; cells 23.40 - 28.35;; long. Intermingled with other algae and higher aquatic plants; Stations 3,4,5. Tribonema Ms (Wille) Hazen 1902 P1. 5 fig. _1_ Prescott 1962, page 368. Filaments 5 - 6.24;; in diameter; cells 21.84 - 26. 52/4 in length. In shallow water of the lake intermingled with aquatic vegetation: Stations: C. 1.2.3.4.5. Tribonema utriculosum (Kuetz.) Hazen 1902 P1. 2 figs. g & _ig Prescott 1962, page 368. Filaments 15.60 - 16.0;1. in diameter; cells 29.64 — 32.76,»: in length. In shallow water of the lake: Stations 0.3.4. 5. Tribonema viride Pascher 1925 Pascher in Rabenhorst Kryptogamen Flora )CI Heterokonten 1939, page 975. Filaments 12.48 — 13.0}; in diameter; cells 28.08 - 34.32 — 57.72/41. in length. Intermingled with other algae and higher aquatic vegetation: Stations C.l.2,3,4.5. Order Heterosiphonales Family Vaucheriaceae Manchega De Candolle 1805 Vaucheria geminata (Vauch.) De Candolle 1805 P1. 5 fig. 8 Prescott 1962. page 292. Filaments 81.0 - 85.80% in diameter; oogonia 80. 52/. in diameter; 81.12/ulong. 127 Floating mats in shallow areas of the lake and intermingled with aquatic vegetation: Stations C.D.l.4, 5. Class Chrysophyceae Order Chrysomonadales Subordeer Isochrysidineae Family Synuraceae Synura Ehrenberg 1838 Sy_nura uvella Ehrenberg 1838 Prescott 1962. page 376. Cells 12.84 - 14.04,.tin diameter; 20.28 - 21.84;; in length. Explankton: Stations D.I.III4 - D. 1.2.3. Suborder Ochromonodineae Family Ochromonadaceae W Ehrenberg 18 35 Dinobrzon glindricum Imhof 1883 ex Ahlstrom 1937 P1. 5 fig. 2 Prescott 1962. page 378. Loricas 8.58 - 10.5,“. in diameter at the mouth 28.08 - 42.0/u. long. Euplankton: Stations C,D,D - I - II - III. Tychoplankton: Stations C .D .1, 5. Dinobmon divergens Imhof 1887 P1. 2 fig. _1_1_ Prescott 1962. page 378. Loricas 7.80 — 10. 5,44. in diameter at the mouth; widest point at mid-region 10.5,. in diameter; loricas 35.88 - 39.0}. long. Euplankton: Stations C,D.D - I - II. II ..III. III - D. Dinobryon sertularia Ehrenberg 1835 P1. 5 fig. _1_} Prescott 1962. page 378. Loricas 9.36 - 10.0,u. in diameter at the mouth; 29.60 - 32.76/11 in length. Euplankton: Stations C,D.D - I, I - II. II -I[I. III - D.5. Tychoplankton: Stations C,D. Aufwuchs: Artificial Substrates Stations A,B. 128 Dinobgyon sociale Ehrenberg 1835 . P1. 5 fig. 19 Prescott 1962. page 379. Loricas 8.52 - 9.72/Lin diameter at the mouth; 32.40 - 53.04,... in length. Euplankton: Stations C,D.D — I - I4, I4 - II. II - III. III - D. Class Bacillariophyceae The Diatoms collected in the course of this study were identified to genus. They were found in all the variety of habitats in the lake: Euplankton. Tychoplankton, and AufWuchs. throughout the year. Order Centrales Suborder Coscinodiscaceae Family Coscinodiscaceae Melosira varians Ag. Reported by Tucker (1957). Order Pennales Suborder Fragilarineae Family Tabellariaceae Diatomella Greville 1855 Family Diatomaceae Diatoma De Candolle 1805 Family Fragilariaceae Asterionella formmsa Hess. Reported by Tucker (1957) Fragilaria Lyngbye 1819; emend., Rabenhorst 1864 Fragilaria crotonesis Kitt. Reported by Tucker (1957) Sygedra Ehrenberg 1830 Smedra pulchella var. longissima W. Smith Reported by Tucker (1957) 129 suborder Achnanthineae Family’Achnanthaceae Achnanthes Bory 1822 Cocconeis Eirenberg 1838 Suborder Naviculineae Family Naviculaceae Navicula Bory 1822 Pinnularia Ehrenberg 1840 Family Gomphonemataceae Goonnema Agardh 18 24 Family Cymbellaceae uphora Ehrenberg 1840 Embella Agardh 1830 Epithemia De Brebisson 1838 Rhapalodia O. Muller 1895 Suborder Surirellineae Family Nitzschiaceae Nitzschia Hassall 1845 Family Surirellaceae Qyugtopleura W. Smith 1851 Division Pyrrhophyta Class Dinophyceae Order Peridiniales Family Peridinaceae Peridinium Ehrenberg 1832 Peridinium him Stein 1883 P1. _6_ fig. 5 Schiller in Rabenhorst's Kryptogamen Flora Band X. 2. Teil. 1937. Page 158. 130 Cells 65.52 - 67.08pm diameter; 67.08 — 70.20/14. in length. Tychoplankton: Stations 4, 5. New record for Michigan. Peridinium inconspicuum Immemarm 1899 P1. _6 fig. 4 Schiller in Rabenhorst's Kryptogamen Flora Band X, 2. Teil. 1937, page 173. Cells 24.96 - 28.08/Lin length; 18.72 - 21.84pm diameter. Euplankton: Stations D - I - I4. II4 - II - C. II - III. Tychoplankton: Stations C.D.l.2.4.5. Peridinium umbonatum Stein 1883 P1. _6_. fig. 5 Schiller in Rabenhorst's Kryptogamen Flora Band X. 2. Teil. 1937. Page 171. Cells 33.78 - 26.52pm diameter; 23.40 - 29.62/Lin length. Eaplankton: Stations I - II, II4 - II - C, II - III. Tychoplankton: Stations C - D. 1.2.4.5. New record for Michigan. Pendinium Volzii Lemmermann 190 5 Pl. 6 fig. _2 Schiller in Rabenhorst's Kryptogamen Flora Band X. 2. Teil. 1937. page 171. Cells 51.48 — 53.04,uin diameter; 53.46 — 54.60,“.in length. Euplankton: Station 5. Tychoplankton: Station 5. New record for Michigan. Peridinium Willei Huitf. - Kaas. 1900 Pl. 5 fig. 1 Schiller in Rabenhorst's Kryptogamen Flora Band X. 2. Teil. 1937. page 147. Cells 48.60 — 54.60pm diameter; 50.72 .. 54.60/tin length. Euplankton: Stations C. 5. Tychoplankton: Stations 4.5. 131 Family Ceratiaceae Ceratium Schrank 1793 Ceratium hirundinella (O.F.Muell.) Dujardin 1841 P1. 5 figs. _6_ a _7_ Prescott 1962. page 437. Cells varying in size and morphological shape depending upon the environmental conditions; 202.75 .- 226.05,u. in length. Euplankton: Stations C.D.D - I - II - III. III - D.6.7. Tychoplankton: Stations C,D. Water bloom proportions at stations 0,6,7. Associated with fish kill. Division Euglenophyta Class Euglenophyceae Order Euglenales Family Euglenaceae Euglena Ehrenberg 1838 Euglena _a_._c_1_1_s_ Ehrenberg 1838 P1. 2 fig.4 Gojdics 1953. page 99. Cells 6.75 - 9.72pm diameter; 91.04 - 134. ZO/L in length. ‘chhoplankton: Station D. Euglena 9M Schmarda var. m_in__o_r Prescott 1944 P1. 2 fig.5 Prescott 1962, page 393. Cells 15.60 - 17.16/win diameter; 79.56 - 81.12/Lin length. In shallow water at station C. Euglena spp. There were at least four other species of gglena present in the lake. but they were not identifiable due to lack of material showing the necessary taxonomic characters. Shallow water: Station D, 5. Euplankton: Station D. 132 Phacus Dujardin 1841 Phacus acuminatus Stokes 1885 Pl.‘§ fig. 3 Prescott 1962, page 396. Cells m.28 - 21.84pm diameter; 25.25 - 28.08/u. in length. In shallow water. along the shore of station: D. Euplankton: Station D. Phacus ankylonaton Pochmann 1942 P1. §_fig. 13 HuberaPestalozii 1955. page 196. Cells 23.40 - 24. 30pm diameter; 43.68 — 45.36pm length. Slightly larger than the typical. In shallow water of station 6. New record for North America. previously reported from Poland, Czechoslovakia. Phacus caudatus Huebner 1886 P1. § fig. 2 Prescott 1962, page 398. Cells 17.16 — 21.84p.in diameter; 35.0 - 43.68fl1n length. Euplankton: Stations C,D. Tychoplankton: Stations C,D. Phacus contortus var. complicate Bourrelly 1952 Pl. 2 fig. 1 Huber-Pestalozii 1955. page 205. Cells 32.40 - 34.02/uin diameter; 43.74 — 46.98}; in length. This is a new record for North America. the species. along with its two varieties. has only been reported twice; by Bourrelly in 1952, (Guadeloupe) and 1961 (Cote d'Ivoire.) The alga resembles var. complicate as illustrated by Bourrelly in G.HuberePestalozzi 1955. but it is slightly larger in all measurements. Tychoplankton: Station D. 133 Phacus gi_.‘g_a_§ De Ounha 1913 P1. Z fig. 3 Huber-Pestalozzi 1955. page 210. Cells 72.90 — 74.95pm diameter; 116.45 — 123.12/1. in length. Slightly longer than measurements given for this species. Tychoplankton: Station C. Phacus lismorensis Playfair 1921 P1. Z fig. _4 HuberaPestalozzi 1955. page 219. Cells 35.60 - 37.0};- in diameter; 114.07 - 123. 30}; in length. A new record for North America. previously reported from Australia, Europe, Russia and Java. The measurements larger than those in the original description. agree with those given by Skuja 1948. Tychoplankton: Stations C. D , 5. Phacus longicauda (Ehrenb.) Dujardin 1841 P1. 7 figs. 2 & 8 Huber-Pestalozzi 1955. page 220. Cells 45.24 -49.92/u.in diameter; 78.00 - 79.56;» in length. Euplankton: Station C. TychOplankton: Station C. Phacus longicauda var. insecta Koczwara 1915 P1. _7_ figs. 5 8c 5 Huber-Pestalozzi 1955. page ? Cells 41.31 - 45.241; in diameter; 106.08 - 123.12,; in length. New record for North America. previously found in Poland, South Africa and Java. Tychoplankton: Stations D.4. Phacus longicauda var. £13593: Swirenko ? Pl. 8 fig. _1_8 Huber-Pestalozzi 1955. page ? Cells 46.98 - 63.78/Lin diameter; 147.62 - 150.70/uvin length. This plant was slightly smaller in length than the measurements given for the variety, however. it is so large. and fits well otherwise. that it is placed here. 134 New record for North America. previously reported in Russia, Australia and Venezuela. Euplankton: Station II. TychOplankton: Station 0.. Phacus orbicularis Huebner 1886 5 P1. 8 fig. 1 Prescott 1962. page 401. Cells 34.83 - 35.64pm diameter; 50.22 - 51.84/11. in length. Euplankton: Stations II4 .- II, III - D. TychOplankton: Stations D. 4. 5. Phacus orbicularis fa. P1. 8 fig. _2_ Cells 29.64 - 30.0,.» in diameter; 45.24 - 46.0}; in length. Tychoplankton: Station D. Phacus platelea Drezepolski 1925 P1. 8 fig. 2 Huber—Pestalozzi 1955, page 210. Cells 24.96 - 25.0}tin diameter; 35.88 - 36.0,uin length. Entered here with a question mark because not enough material was seen. Tychoplankton: Station D. Phacus p1§uronectes (0.F.M.) Dujardin 1841 P1. 8 fig. 4 Huber—Pestalozzi 1955. Page 211. Cells 42.12 _ 61.56,» in length; 31.20 - 43.74/u in diameter. Tychoplankton: Station D. Phacus pseudowirenkoi Prescott 1944 P1. 8 fig. 8 Prescott 1962. page 402. Cells 27.54 - 32.40/tin diameter; 42.12 — 43.68/u. in length. Tychoplankton: Stations C , II. Phacus rudicula (Playf.) Pochm. 1942 Pl. 2 fig. 8 HuberaPestalozzi 1955. page 233. Cells 15.60 - 16.0/win diameter; 39.0 - 43.74/1m length. 135 New record for North America, previously reported in Central Europe and Australia. Tychoplankton: Station D. Phacus setosus France ? Pl. 8 fig. 8 HuberaPestalozzi 1955, page 191. Cells 17.16 — 17.5,,Lin diameter; 26.52 - 32.76,» in length. Tychoplankton: Station D. Phacus tortus (Lemm.) Skvortzow 1928 Pl. 2 fig. 2 Prescott 1962. page 404. Cells 51.84 - 52.0”.in diameter; 101.40 - 102.75p.in length. Tychoplankton:Station D. Phacus undulatus (Skv.) Poch. 1942 P1. 8 fig. 1_2_ Huber-Pestalozzi 1955, page 214. Cells 37.44 - 38,,tin diameter; 57.72 - 58,1 in length. Tychoplankton: Station D. Phacus Lnguis Pooh. 1942 7 Pl. 8 fig. 11 Huber-Pestalozzi 1955. page 217. Cells 20.28 - 21.84,... in diameter; 31.20 - 32.76,. in length. New record for North America previously reported in Hungary and South America. Tychoplankton: Station D. Phacus sp. A. - P1. 8 fig. 15 Cells 15.60 - 16.0/min diameter; 34.32 - 35.0/win length. This is possibly a new variety of P11. undulatus. Tychoplankton: Station D. Phacus sp B — P1. 8 fig._18 Cells 22.68 - 23.0/tin diameter; 38.07 - 38.5,...in length. Possibly another variety of P11, undulatus. Tychoplankton: Station C. 136 Phacus sp.C .. Pl. 8 fig. _1_.2 Cells 23.49 . 24.0» in diameter; 42.12 — 43.0,“ in length. Possibly another variety in the £8. undulatus species complex. Tychoplankton: Station 4. Phacus sp. 2 - P1. 8 fig. _l_0_ Cells 23.40 — 24,“, in diameter; 39.0 - 40.56,“. in length. A large paramylon plate in the center of the cell, several small paramylon rings. A new variety of P_h_. undulatus ? ‘chhoplankton: Station C. Phacus sp. E - Pl. 8 fig. 2 Cells 21.25 - 21.0}; in diameter; 30.78 - 31.0114. in length. Periplast longitudinally striated; margin of the cells notched just above medium line; paranwlon bodies 5 rings Sp. Nov.? Tychoplankton: Station D. Phacus sp. F - Pl. 8 fig. _1_.& Cells 28.08 - 29.16Iuin diameter; 34. 32 - 38.0/Lin length. Periplast longitudinally striated; margins notched; paramylon bodies, 2.3 rings. Tychoplankton: Station D. Phacus sp. G - Pl. 8 fig. 11 Cells 18.72 - 20.28/pin diameter; 34.32 — 39.0/u. in length; 2.3 paramylon bodies. This may ben an expression of £13. anlgglonoton. Tychoplankton: Stations C,D. Phacus sp. H — P1. 2 fig. _1_8 Cells 21.06 - 22.0,uin diameter; 34. 32 - 35.0/Lin length. Close to Ph. applanatus Poch. Tychoplankton: Station D . Phacus sp. I - Pl. 2 fig. _2_(_)_ Cells 29.36 - 30,41. in diameter; 87.37 - 90.0}. in length. Appears similar to Ph. filicauda Poch., but not enough material seen. Tychoplankton: Station D. a ‘Illllll [Ll It I l l. 137 Lepocinclis Party 1849 Lepocinclis ovum (Ehrenb.) Lemmermann 1901 P1. 2 fig. .1. Prescott 1962. page 407. Cells 12.96 — 13.0pvin diameter; 22.68 — 24.30p.in length. Tychoplankton: Station 3. Trachelomonas Ehrenberg 1835 Trachelomonas australica var. rectangularis Deflandre 1926 P1. 2 fig. _1_o_ Huber-Pestalozzi 1955, page 304. Test 19.56 - 20.28p.in diameter; 32.76 - 33.0nIin length. Tychoplankton: Stations D,l. Trachelomonas lelg (Stein ) Deflandre 1926 Pl. 3 fig. g; Huber-Pestalozzi 1955. page 340. Test 21.06 - 22,0.in diameter; 32.40 - 33/u. in length. Tychoplankton: Station 5. Trachelomonas cylindrica Ehrenberg ? P1. 2 fig. 2 Prescott 1962, page 412. Test 11.0 - 11.34p.in diameter; 30.0 - 32.40p.in length. This plant is longer than measurements given for the species. Tychoplankton: Station 4. Trachelomonas beowskii Drezepolsi 1922 P1. 2 fig. 5 Prescott 1962, page 412. Test 16.0 - 16.20p.in diameter; 19.02 - 19.44A,in length. Ehplankton: Station D.. Tychoplankton: Stations C,D.. Trachelomonas hispida (Perty) Stein 1883 P1. 2 fig. _6_ Prescott 1962, page 414. Test 21.84 - 23.49% in diameter; 23.40 — 27.30;oin length. Euplankton: Station D. Tychoplankton: Stations D,l,2. ‘I nll‘u‘t‘l,l ‘11" II 135 Trachelomonas hispida var. duplex Deflandre 1926 P1. 2 fig. 1 Huber—Pestalozzi 1955, page 295. Test 19.50 - 20.0;Lin diameter; 26.52 - 27.0/u. in length. Tychoplankton: Station D. Trachelomonas obovata var. Klebsiana Deflandre 1926 P1. 2 fig. _12 Huber-Pestalozzi 1955, page 316. Test 16.20 - 16.5,u.in diameter; 24.30 - 25.0/win length. Tychoplankton: Station C. Trachelomonas glanctonica var. oblonga Drezepolski 1921-22 Pl. 2 fig. _1_2 HuberaPestalozzi 1955, page 328. Test 19.44 .- 20.28/min diameter; 28.24 — 31.20/Lin length. Tychoplankton: Station D. Trachelomonas pulcherrima Playfair 1916 P1. 2 fig. 8 Huber-Pestalozzi 1955, page 289. Test 17.5 - 18.72/win diameter; 35.0 - 35.88/u. in length. Measurements larger than those given for the species but looks the same. Tychoplankton: Station D. Trachelomonas splendidissima Middelh. 1948 P1. 2 fig. 12 Huber-Pestalozzi 1955, page 287. Test 18.72 - 19.5/u-in diameter; 29.62 - 32.76/u, in length. Tychoplankton: Station D. Trachelomonas volvocina Ehrenberg 1933 P1. 2 fig. L4 Prescott 1962, page 419. Test 18.63 — 20.0”. in diameter. Tychoplankton: Station D.4. 139 Trachelomonas.volvocinopsis var. punctata (Skv.) Bourrelly 1952 P1. 2 fig. _1_8 Huber-Pestalozzi 1955. page 254. Test 20.5 - 22.68,u.in diameter. Tychoplankton: Station 4. Family Peranemaceae Anisonema Dujardin Ani§onema SP. '- P10 2 fig. _11 Cells 17.16 - 17.5/win diameter; 31.20 - 32.0/Lin length. Tychoplankton: Station D. Division Chlorophyta Class Chlorophyceae Order VOlvocales Family Chlamydomonadaceae Chlamydomonas Ehrenberg 1835 CMMomonas pseudopertyi Pascher 1927 P1. 2 fig. g; Prescott 1962. page 72. Cells 20.28 - 21.06/Lin diameter; Tychoplankton: Station C. Family Volvocaceae Pandorina Bory 1824 Pandorina morum (Muell.) Bory 1824 Prescott 1962. page 75. Cells 10.92 - 11.59luin diameter; 13.24 — 14.04/tin length. Tychoplankton: Station D. Didorina Ehrenberg 18 32 Eudorina elegans Ehrenberg 1832 P1. 2 fig. _21_ Prescott 1962. page 76. Cells 19.48 - 20.28/Loin diameter. 140 Colonies up to 123.30,“ in diameter. Euplankton: Stations II - III. 5. Order Tetrasporales Family Palmellaceae Sphaerocystis Chodat 1897 Sphaerocystis Schroeteri Chodat 1897 P1. l8 fig. 2 Prescott 1962. page 83. Cells 7.8 - 8.10/Lin diameter. Euplankton: Stations C,D. Tychoplankton: Stations C. 1.4. Aufwuchs: Artificial Substrates Station A. Gloeocystis Naegeli 1849 Gloeocystis‘ggggg (Kuetz.) Lagerheim 1883 Prescott 1962. page 84. Cells 9.36 - 11.34u.in diameter. Euplankton: Station 4. Tychoplankton: Stations 4,5. Family Tetrasporaceae Tetraspora Link 1809 Tetraspora gelatinosa (vauch.) Desvaux 1818 Prescott 1962. page 88. Cells 3.12 — 4.68/Lin diameter in young plants. Cells 10.92 — 12.48;c in diameter in older plants. Attached to sunken logs. and aquatic vegetation: Stations D. 1.2.3.4. Aufwuchs: Artificial Substrates Station A. Family Coccomyxaceae Chlorosarcina Gerneck 1907 Chlorosarcina consociata (Klebs.) G.H.Smith 1933 Smith 1930. page 135. Cells 11.34 - 14.58;Lin diameter. Placed here with a question mark. not enough material seen. 141 nor enough literature on this species available. Tychoplankton: Station D. Elakatothrix Willa 1898 Elakatothrix viridig (Snow) Printz 1914 Prescott 1962. page 93. Cells 4.68 — 6. 24;» in diameter; 24.96 — 26.52/u. in length. Euplankton: Station I. Aufwuchs: Artificial Substrates Station A. Dispora Printz 1914 Dispora crucigenioides Printz 1914 P1°.$3 fig. 2 Prescott 1962. page 93. Cells 3.24 — 3.5/pin diameter; 4.86 — 5.0/u in length. Euplankton: Stations II - III. Tychoplankton: Station D. Aufwuchs: Artificial Substrates Station A. Order Ulotrichales Suborder Ulotrichineae Family Ulotrichaceae Ulothrix Kuetzing 1833 Ulothrix tenerrima Kuetzing 1843 Pl. ;2 fig. _1_ Prescott 1962, page 96. Filaments 6.48 — 7.292Lin diameter; cells 9.72 - 10.92/Lin length. Intermingled with other algae along the shore: Station D. Tychoplankton: Station D. Suborder Schizomeridineae Family Schizomeridaceae Schizomeris Kuetzing 1843 Schizomeris Leibleinii Kuetzing 1843 Prescott 1962, page 105. Filaments 20.28 - 24.96/tin diameter toward the base; 48.36 - 56.1620 142 in the multiseriate portion further up. Cells 15.60 — 21.84}bln diameter. Shallow water of lake shore: Stations C.D.4. Order Microsporales Family Microsporaceae Microspora Thuret 1850 Microspora elegans Hansgirg 1891 P1. 12 fig. _2_ Prescott 1962. page 107. Cells 14.58 - 15.0,u. in diameter; 22.68 - 23.0,»: in length. Intermingled with other algae along the shore. Euplankton: Station D. Microgpora tumidula Hazen 1902 Pascher 1914. Heft 6: Chlorophyceae III. page 151. Cells 6.24 — 7.Qu.in diameter; 10.92 - 11.0/Lin length. Shallow water along shore intermingled with other aquatic vegetation: Station C. Microspora Willeana Lagerheim in De Toni 1889 Prescott 1962. page 108. Cells 12.48 - 12.5/pin diameter; 14.04 - 15.60/4. in length. Intermingled with other algae in Plankton Sample: Station D. Order Cylindrocapsales Family Cylindrocapsaceae Cylindrocapsa Reinsch. 1867 Cylindrocapsa geminella wolle 1887 , P1. l2 fig. 2 Prescott 1962. page 110. Cells 12.48 — 12.5}Lin diameter; 20.28 - 20.5/Lin length. Entangled'with other algae: Station 5. Aufwuchs: Artificial Substrates Station A. 143 Order Chaetophorales Family Chaetophoraceae Stigeoclonium Kuetzing 1843 Stigeoclonium fascicular Kuetzing 1847 Islam.1960. page 214. Reported by Islam.in thesis titled "A Revision of Stigeoclonium and Critical Studies in Related Genera" Michigan State University. Stigeoclonium flagelliferum Knetzing 1895 Prescott 1962. page 115. Cells 12.48 - 17.16/win diameter; 49.92 — 88.92/u,in length. in the main filament. Attached to stones and wood along the shore: Station D. Stigeoclonium lubricum (Dillw.) Kuetzing 1845 Prescott 1962. page 115. Cells along the main axis 10.22 - 11.5/u,in diameter; 25.92 — 26.52/u. in length. Attached to stones along the lake shore: Stations C.D.3.4,5. Stigeoclonium.£gggg (C.A.Ag.) Kuetzing 1843 ' P1. _1_§_ fig. _1_ Prescott 1962. page 115. Cells of the main axis 7.80 - 9.36y;in diameter; 12.48 - 18.72 - 21.84fltin length. Attached to stones and logs along the lake shrore: Stations C.D.l. In plankton samples: Stations C,D. Draparnaldia Bory 1808 Draparnaldiagglomerata (vauch.) C.A.Agardh 1812 P1. 12 fig. Z Prescott 1962. page 120. Cells of the main filaments 54.60 - 55.0/Lin diameter; 84.24 - 116.45u.in length. Cells of the fascicles 7.80 - 9.36/:in diameter. Lake shore: Stations 1.2.3. In the shallow water along the lake shore. where an underground stream flows into the lake: Station C. 144 Family Coleochaetaceae Coleochaete De Brebisson 1844 Coleochaete orbicularis Pringsheim 1860 Prescott 1962. page 129. Cells 10.92 - 11.86,“ in diameter; 12.48 — 13.5)“, in length. Colonies 49.92 - 53.04p.in diameter. Attached to: Aufwuchs Artificial Substrates Station A. Order Cladophorales Family Cladophoraceae Cladophora Kuetzing 1843 Cladophora fracta (Dillw.) Kuetzing 1843. Prescott 1962. page 137. Cells 82.68 - 109.6Qp.in diameter; 294.55 - 301.40pcin length. Cells in secondary branches 39.0 - 40.56#.in diameter; 109.60 - 116.45}. in length. Intermingled with other algae at: Station D. Cladophora glomerata (L.) Kuetzing 1845 Prescott 1962. page 138. Cells of the main filament 73.7 - 87.1/oin diameter; 402.0 - 448.022 in length. and cells of the ultimate branches 20.2 - 26.8ugin diameter; 201.- _26l.3/,oin length. Intermingled with other algae: Stations C,D.8. Euplankton: Stations III - D. Cladophora insignis (C.A.Ag.) Kuetzing 1845 Prescott 1962. page 139. Cells of the main filaments 109.60 — 116.45u.in diameter; 341.50 - 685.0;oin length; cells of the branches 68.50 — 70.292c in diameter up to 581.5Qp.in length. Forming floating mats of mixed algae: Station D. 145 Rhizoclonium Kuetzing 1843 Rhizoclonium crassipellitum west & west 1897 Prescott 1962. page 141. Cells of the filament 51.48 - 71.76u;in diameter; 109.60 — 123.30 - 150.70y,in length. Entangled with other algae: Station D. Order Oedogoniales Family Oedogoniaceae Bulbochaete C.A.Agardh 1817 Bulbochaete sp. Cells 18.72 - 19.0/,Lin diameter; 39.00 — 40.56/42 in length. Not identified species because the plant was never found reproducing: Station 5. Oedogonium Link 1820 Oedogonium g1obosoum Nordstedt 1878 P1. 12 fig. 5 Prescott 1962. page 178. Cells 11.34 - 12.0/pin diameter; 51.84 - 63.78/ein length; oogonia 40.50 - 42.12/Lin diameter; oospores 32. - 38.88;;in diameter. On submerged aquatic vegetation: Stations C.5. Oedoggnium Pringsheimii Cramer 1859 P1. 12 fig. 2 Prescott 1962. page 187. Cells 12. 96 - 16.20/u, in diameter; 42.12 — 46.98,“.in length; oogonia 39.88 - 42.121Lin diameter. 35.64 - 36.9u.in length; oospore 34.32 - 35.0;tin diameter. On stones: Station D. Oedogonium sp. There were at least 6 or 7 other species of Oedogonium in the lake. However. they were never found reproducing. and were not identified to species: collected at all stations. 146 Order Chlorococcales Family Chlorococcaceae Golenkinia Chodat 1894 Golenkinia radiata (Chod.) Wille 1911 P1. _1_9 fig. 1; Prescott 1962, page 213. Cells 9.72— 10.0;pin diameter. Setae 25.92 - 26.52/4. in length. Euplankton: Stations C,D. Family Hydrodictyaceae Pediastrum Meyen 1829 Pediastrum biradiatum.Meyen 1829 fa. Prescott 1962, page 222. Cells 15.60 - 18.72fibin diameter. Colonies of 6 cells 36.0 - 37.44p.in diameter. Tychoplankton: Station 5. Pediastrum Bogyanum (Turp.) Meneghini 1840 P1. 1; figs. ;,_7_ a g Prescott 1962. page 222. Cells 10.5 - 17.16;;in.diameter; 14.0 - 21.84fblong; l6 celled colony 42.0 - 45.0/tin diameter. Included under §. Bogyanum are two other plants. which would correspond to other authors; 2. glanduliforum and g. gganulatum. but included here as formas. following Bigeard's (34) interpretation of this species. EUplankton: Stations C.D.D - I - II. II - III. III - D. 1.2.3.4.5. Tychoplankton: Stations C,D. 1.2.3.4,5. Aufwuchs: Artificial Substrates Station A,B. Pediastrum Boryanum var. longicorne Raciborski 1889 P1. 11 fig. _4 Prescott 1962. page 222. Cells 14.04 - 18.72/pin diameter. 21.84 — 22.0};- long. Colonies of 16 cells 56.0 - 63.0/Lin diameter. EUplankton: Stations C.D.D - I - II. II - III - D. Tychoplankton: Stations C.D.l.3.4.5. 147 Pediastrum duplex Meyen 1829 P1. 11 fig. 1 Prescott 1962, page 223. Cells 17.5 - 18.25;»in diameter. Colonies of 32 cells 119.0 - 120.76/Lin diameter. EUplankton: Stations C.D.D - I - II. II - III. III - D. 1.3.4.5. Tychoplankton: Stations C,D,4.5. Aufwuchs: Artificial Substrates Station A. Pediastrum ggplex var. clathratum (A.Braun) Lagerheim 1882 P1. 11 fig. 2 Prescott 1962. page 223. Cells 13.7 - 16.20y-in diameter. Colonies of 32 cells 92.37 — 94.9u.in diameter. Euplankton: Stations C,D. Pediastrum integrum.Naegeli 1849 Prescott 1962. page 225. Cells 17.16 - 21.8Qp.in diameter. Colonies of 16 cells 68.64 - 79.56/tin diameter. Euplankton: Stations C,D. Pediastrum integrum var. pgrforatum Raciborski 1889 fa. P1. 11 fig. 12 Raciborski 1889. page 7. Cells 29.64 - 31.29;»across. 23.40 - 24.96u.in length. Colonies of 22 cells 137.0 - 150.70/Lin diameter. The plant resembles var. perforatum except the projections are bifurcate. may be just a fa. Euplankton: Station D. Aufwuchs: Artificial Substrates Station A. Pediastrum simplex (Meyen) Lemmermann 1897 Prescott 1962, page 227. Cells 19.0 - 19.4¢~in diameter, 31.20 — 32.40/bin length. Euplankton: Stations C,D. 148 Pediastrum simplex var. duodenarium (Bailey) Rabenhorst 1868 P1. _11 fig. 5,3 Prescott 1962. page 227. Cells 14.24 - 15.0;Lin diameter. 22.68 - 23.4Qu.in length. Colonies of 16 cells 76.64 .. 78.0,“ in diameter. Euplankton: Stations C,D. Pediastrum tetras (Ehrenberg) Ralfs 1844 P1. 11 figs. 2 & 8 Prescott 1962. page 227. Cells 7.80 - 8.10pm diameter. Colonies of 4 cells 14.04 - 15.60/tin diameter. colonies of 8 cells 22.64.- 28.08/L in diameter. Euplankton: Stations C.D.D - I - II. II - III, 1.3.4.5. Aufwuchs: Artificial Substrates Station A. Family Botryococcaceae glgtzlgcoccus Kuetzing 1849 Botryococcus braunii Kuetzing 1849 P1. 12 fig. 21 Prescott 1962, page 232. Cells 6.24 - 7.80/Lin diameter. 10.92 - 11.0;Lin length. Euplankton: Stations C.D.D - I — II. II — III, III - D,4,5. Aufwuchs: Artificial Substrates Station A. Family Oocystaceae Dictyosphaerium Naegeli 1849‘ Digtyosphaerium pulchellum wood 1874 P1. 12 fig. 1_4 Prescott 1962. page 238. Cells 6.24 — 8.10pm diameter. Euplankton: Stations C.D.D - I. II - III. Tychoplankton: Stations C . D .1 . 149 Oocystis Naegeli 1855 Oocystis g1g§§ Archer 1877 P1. 1_0_ fig. 12 Prescott 1962. page 244. Cells 22.68 - 24.96/win diameter. 35.64 - 42.12/win length. Slightly smaller in diameter than measurements given for the species. Euplankton: Stations C. D , 5. Oogystis lacustris Chodat 189? Prescott 1962. page 245. Cells 11.68 - 12.0» in diameter. 15.60 ... 16.0/u long. Euplankton: Stations I. II — III. Nephrocflium Naegeli 1824 Nephrocytium Agardhianum Naegeli 1849 P1. 12 fig. 18 Prescott 1962. page 248. Cells 4.86 — 5.0/u. in diameter. 11.34 - 12.0} in length. Tychoplankton: Stations D,4. Nephrmtium obesum West a West 1894 P1. 12 fig. 22 Prescott 1962. page 249. Cells 15.60 - 16.0/u in diameter. 24.96 - 25.0/u. in length. Cells little shorter than measurements given for this species. but fits well otherwise. Tychoplankton : Stations D. 5. Dimorphococcus A. Braun 1855 Dimorphococcus lunatus A. Braun 1855 Prescott 1962, page 252. Cells 9.36 - 10.0,u. in diameter. 11.34 - l7.gz,clong. Euplankton: Station D. Illlll'll’lllllllil‘l 150 Ankistrodesmus Corda 1838 Ankistrodesmus falcatus(Corda) Ralfs 1848 Prescott 1962. page 253. Cells 2.34 - 3.0;oin diameter. 24.04 — 25.75u.in length. Euplankton: Stations C.D.D - I - II.4.5. Ankistrodesmus spiralis (Turner) Lemmermann 1908 Prescott 1962. page 253. Cells 1.56 — 2.2p.in diameter. 26.52 - 27.2u.in length. Euplankton: Stations D,4. Kirchneriella Schmidle 1893 Kirchnerie11§ contorta (Schmidle) Bohlin 1897 P1. 12 fig. 12 Prescott 1962. page 258. Cells 1.42 - 2.0,u.in diameter. 10.92 - 12.48/L in length. AufWuchs: Artificial Substrates Station A. Kirchneriella lunaris (Kircher) Mobius 1894 P1. 12 fig. 18 Prescott 1962. page 258. Cells 6.24 - 7.82pain diameter. 12.84 - 13.2”.in length. Euplankton: Station I. Kirchneriella obesa (west & West) Schnidle 1893 P1. _13 fig. _1_5_ Prescott 1962. page 259. Cells 2.34 — 3.2M.in diameter. 7.80 - 9.3éu.in length. Euplankton: Station I. Quadrigula Printz 1915 Quadrigula Chodatii (Tan.-Fnl.) G.M.Smith 1920 P1. _1_3 fig. _1_ Prescott 1962. page 260. Cells 6.48 - 7.2psin diameter, 43.86 _ 45.8616in length. Euplankton: Stations C,D. 151 Tetraedron Kuetzing 1845 Tetraedron enorme (Ralfs) Hansgirg 1888 fa. P1. 18 fig. 2 Prescott 1962. page 265. Cells tetragonal; processes bifurcate; cells 21.84 — 23.4Qu.along the long axis viewed from the side. 32.40 - 33.0/~in diameter when viewed from the bottom. This plant does not look like the typical species. however. I believe it is a form. Euplankton: Station D. AufWuchs: Artificial Substrates Station A. Tetraedron minimum (A.Braun) Hansgirg 1888 P1. 1g fig. 2 Prescott 1962. page 267. Cells 6.48 - 14m01tin diameter. Euplankton: Stations C.D.D - I - II. II - III.5. AufWuchs: Artificial Substrates Station A. Tetraedron trigpnum (Naeg.) Hansgirg 1888 P1. 18 fig. 8 Prescott 1962. page 270. Cells 28.08 — 29.2p-in diameter. Euplankton: Stations II - C. Tychoplankton: Stations C,D. 5. Aufwuchs: Artificial Substrates Station A. Tetraedron triggnum var. gracile (Reinsch) De Toni 1889 P1. 18 fig. 8 Prescott 1962. page 270. Cells 34.32 - 35.881Ain diameter. including the spines. Tychoplankton: Station C. Tetraedron tumidulum (Reinsch) Hansgirg 1889 P1. 1g fig. 2 Prescott 1962. page 270. Cells 37.44 - 45.24/tin diameter. Tychoplankton: Station C. 152 Family Scenedesmaceae Scenedesmus Meyen 1829 Scenedesmus abundans (Kuch.) Chodat 1913 P1. 19 fig. 1 Prescott 1962. page 274. Cells 3.12 - 3.5u.in diameter, 7.80 — 8.0poin length. Euplankton: Station D. Scenedesmus arcuatus var. p1atydisca G.S.Smith 1916 P1. 12 fig. 2 Prescott 1962. page 275. Cells 6.7 - 7.0/u. in diameter. 9.0 — 9.36/u. in length. Euplankton: Stations D.D — I - II. Scenedesmus armatus (Chod.) G.S.Smith 1916 P1. 12.fig. Z Prescott 1962. page 276. Cells 4.86 — 5.2p,in diameter. 15.60 - 16.22y.in length. Euplankton: Station C. Scenedesmus bijuga (Turp.) Lagerheim 1893 . P1. 12 fig. 2 Prescott 1962. page 276. Cells 3.5 - 4.2p.wide. 18.5 - 12.25u.in length. Tychoplankton: Stations C,D.l.4,5. Aufwuchs: Artificial Substrates Station A. Scenedesmus dimorphgg (Turp.) Kuetzing 1833 P1. 19 fig. 2 Prescott 1962. page 277. Cells 4.86 - 5.0/fin.diameter. 12.96 - l3.0;:in length. EMplankton: Stations D - I — II4. Tychoplankton: Station D. Aufwuchs: Artificial Substrates Station A. 153 Scenedesmus obliggus (Turp.) Kuetzing 1833 P1. 12 fig. 11 Prescott 1962, page 279. Cells 4.86 .- 6.2414. in diameter. 14.04 — 16.20/11in length. Euplankton: Stations D.D - I - II4. Tychoplankton: Stations C,D. Scenedesmus quadricaudg (Turp.) de Brebisson 1835 P1. 12 fig. 5 Prescott 1962. page 280. Cells 3.5 - 6.24.1111 diameter. 10.5 - 16.20”. in length. Euplankton: Stations C.D.D - I - I4 — II - C. II - III. D,5. Tychoplankton: Stations CZD,1.2.3.4.5.6. Aufwuchs: Artificial Substrates Stations A,B. Scenedesmus quadricaugg var. oarvus G.M.Smith 1916 P1. 12 fig. 12 Prescott 1962. page 280. Cells 5.76 - 6.48p.in diameter. 9.72 - 10.92p.in length. mMmMm:finmmD-I. Scenedesmus quadricauda var. quadrispigg (Chod.) G.M.Smith 1916 P1. _1_9 fig. _6_ Prescott 1962. page 280. Cells 3.51 4.2p.in diameter. 10.92 - 12.48/Lin length. Spines 3.0 - 3.12/«.10ng. Euplankton: Station D. Tetradesmus G.M.Smith 1913 Tetradesmus wisconsinense G.M.Smith 1939 P1. 12 fig. 12 Prescott 1962, page 283. Cells 6.24 — 6.5%Ain.diameter. 7.80 - 8.58u.in length. Euplankton: Station D. 154 Order Zygnematales Family Zygnemataceae Mougeotia (C.A.Agardh) Wittrock 1872 Mougeotia sp. There were at least three species of Mougheotia in Lake Lansing. However, they were never collected reproducing. hence could not be identified to species. Intermingled with other algae along the shores: Stations C.D.l.2.3,4,5.6.7o Spirogyra Link 1820 Spirogyra porticalis (Mue11.) Cleve 1868 P1. 12 fig. 8 Prescott 1962, page 318. Cells 35.88 - 42.12ybin diameter. 105 — 112.0/hlong. Zygospore. 38.5 - 40.25/Lin diameter. 56.16 - 57.72yLin.length. Intermingled with other algae along the shore: Stations C,D,5. Spirogyra rivularis (Hass.) Rabenhorst 1868 Prescott 1962. page 320. Cells 39.0 - 41.lOyuin diameter, 241.56 - 250.5Qu.in length. Zygospore, 48.36 - 51.84ptin,diameter. 87.60 - 97.221tin length. Intermingled with other algae: Station D. Spirogyra singglaris Nordstedt 1880 Prescott 1962. page 320. 06115 29.64 - 31.290.in diameter. 34.02 - 42.12Acin length. Zygospore 24.96 — 29.18/ein.diameter. 34.02 - 42.12/tin length. Intermingled with other algae: Stations C,D,5. Tych oplankton: Stations C . D. 5. Spirogyra sp. There were at least eight or nine other species of Spirogyra present in the lake. They were never found reproducing. hence undeterminable. Collected at all stations. 155 Zygnema C.A.Agardh 1828 2ygnema sterile Transeau 1934 Prescott 1962, page 323. After Prescott. Cells 44 — 54/Lin diameter, 22 - 63uwin long, with a thick wall and inclosed by a firm pectic sheath. Identified by vegetative characteristics. Intermingled with other algae: Stations C,5. gygnema sp. There were two possibly three other unidentifiable species of gygnema. Ehtangled with other algae at all stations and euplanktonic and tychoplanktonic. Family Desmidiaceae Penium de Brebisson 1844 Peniug margaritaceum (Ehrenberg) de Brebisson 1848 P1. 12 fig. 8 Smith 1924, page 7. Cells 23.40 - 24.96/Lin diameter, 253.45 — 260.39u.in length; breadth at apices 18.72 - 20.28/p. Tychoplankton: Station D. Closterium Nitzsch 1817 Closterium acerosum (Shrank) Ehrenberg 1828 P1. 12 fig. _1_3 Smith 1924, page 10. Cells 500.0 - 527.45/4. in length, 37.67 - 41.10/u broad at girdle. Tychoplankton: Station 4. Closterium acerosum var. tumidun Borge 1895 P1. 18 fig. 2 Krieger 1937, page 319. Cells 450.00 - 476.41/tin length. 33.78 - 34.2/abroad at girdle, 6.48 - 6.5/abroad at apex. Tychoplankton: Station D. 156 Closterium incurvum de Breb. 1856 P1. 12 fig. 12 Irenee-Marie 1938, page 69. Cells 112.32 - 117.0;ein length, 17.16 - 17.5/~broad at the girdle, 4.68 - 5.0/abroad at the apex. Tychoplankton: Stations C,5. Closterium leibleinii Kuetzing 1834 P1. 18 fig. 2 Irenee-Marie 1938. page 65. Cells 184.95 - 187.88/tin length, 30.78 - 31.22/obroad at the girdle. Tychoplankton: Station D. Closterium moniliferum (Bory) Ehrenberg 1838 P1. 18fig. _5_ Smith 1924, page 9. Cells 167.75 - 171.25u,in length, breadth at girdle 37.26 - 39.222. Euplankton: Station D. Tychoplankton: Station D. Aufwuchs: Artificial substrates Station A. Closterium pgryglum Naeg. 1849 P1. 12 figs. 12 & 12 Irenee-Marie 1938, page 68. Cells 109.60 - 152.8%;bin length, breadth at girdle 15.60 - 17.16/g. Euplankton: Station III. Tychoplankton: Stations D,l,5. Closterium pseudolunula Borge 1909 P1. 18 figs. 1 &‘2 Krieger 1937, page 305. Cells 442.73 - 448.56/Lin length, diameter at girdle 62.40 - 63.78;», 6.24 — 6.72/Lbroad at apex. Tychoplankton: Station D. 1.- III llllcilr 11! Illil ‘Illlvl 1 157 Closterium striggsum de Breb. 1856 P1. 18 figs. 1 & 2 Irenee-Marie 1938, page 82. Cells 294.50 - 300.02/Lin length, 18.72 - 18.90/oin diameter at the girdle. Tychoplankton: Station D. Closterium sublaterale Ruzicka 1957 P1. 12 fig. 12 Ruzicka 1957. page 142. Cells 315.10 - 321.95/pin length, 47.95 - 50.2;tbroad at the girdle. Tychoplankton: Station D. Pleurotaenium Naegeli 1849 Pleurotaenium Ehrenbe£g11(de Breb.) De Bary 1858 P1. 12 fig. 2 Smith 1924, page 15. Cells 348.92 - 583072flbin length, diameter of isthmus 26.84 - 46.9732. Euplankton: Station C. / Tychoplankton: Station C. Pleurotaenium trabecula (Ehrenberg) Naegeli 1849 P1. 12 figs. 12 & 11 Smith 1924, page 14. Cells 465.80 - 617.32ybin length, 33.55 - 54.8222broad at the base of the semicells. Tychoplankton: Stations D.1.2,3,4,5. Euastrum Ehrenberg 1832 Euastrum hypochondrum fa. decoratum Scott & Pres. 1952 P1. 12 fig. 8 Scott and Prescott 1952, page 386. Cells 63.0 - 64.80/Lin length, 59.5 - 63.78;;in diameter, 35.0/L across. 14.0 - 14.58/Lat the isthmus. New record for’Michigan, previously reported from Florida. Euplankton: Stations C.D.D - I - II. Tychoplankton: Stations C,D. . ... oil‘s: fl 158 Euastrum insulare (Wittr.) Roy 1883 P1. 1g fig. ; Irenee-Marie 1938, page 140. Cells 29.64 - 30.22ein length, 18.72 - 19.2;tin diameter, 5.46 - 6.0/mat the isthmus. Euplankton: Stations II3 — II. Aufwuchs: Artificial Substrates Station A. Euastrum insulare var. basichondrum Messik. 1938 P1. 12 fig. 2 Messikommer 1938, page 162. Cells 28.0 - 31.5/oin length, 18.25 — 21.22cin diameter, 5.25 - 7.0;ein diameter at isthmus. Euplankton: Stations II - C. D - I - II. Euastrum turneri w.& w. 1893 Krieger 1937. page 589. Cells 35.68 - 37.442Lin.1ength, 25.92 - 26.52/Lin diameter, isthmus 4.68 - 5.0;»in diameter. Euplankton: Stations D - I. Euastrum turneri W}&H. fa. P1. 12 fig. Z Cells 21.84 - 23.0;oin length, 17.16 - 17.501cin diameter. 4.0 — 4~68f¢broad at the isthmus. Smaller than typical. Euplankton: Station D. Tychoplankton: Station D. Aufwuchs: Artificial Substrates Station A. Micrasterias Agardh 1827 Micrasterias sol (Ehrenb.) Kuetzing 1849 P1. 12 fig. 2 Krieger 1939, page 93. Cells 123.30 - 130.15/bin diameter, 137.0 - 149.78%oin length, isthmus 24.96 - 25.Qy.broad. Tychoplankton: Station 5. 159 Staurastrum Meyen 1829 Staurastrum bienneanum var. ellifiicum Wille 1879 P1. 1g fig. 11 Croasdale 1957. page 142. Cells 37.38 - 38.0/win length, 35.64 - 36.0/win diameter, isthmus 11.34 - lZ/wbroad. Euplankton: Stations D - I. Staurastrum Brebissonii Arch. 1861 P1. 18 fig. 12 Croasdale 1957. page 142. Cells 59.28 - 60.0 ”in length without spines, with spines up to 65.52/44, cells in diameter 54.60 - 55.0/iwithout spines, up to 60.0/uisthmus 20.28 - 21.84/Abroad. Tychoplankton: Station C. _S__taurastrum chaetoceras (Schroder) Smith 1924 P1. 18 fig. 2 Smith 1924, page 99. Cells 40.50 - 42.12/Lin length with processes, breadth 55.08 - 58.32/14, breadth at isthmus 5.67 - 6.0/u. Euplankton: Stations D - I. Staurastrum disputatug W.& w. 1912 P1. 1Z fig. 5 West & West 1912, Vol. IV, page 176. Cells 24.96 — 31.20/win length, breadth 31.20 - 32.0,“. isthmus 7.80 - 9.36/“broad. Smaller than the measurements given for the original. but smaller variety has been discribed. Tychoplankton: Station 5. Staurastrum floriferum w. 8: w. 1896 P1. 18 fig. 8 Smith 1924, page 91. Cells 27.92 - 28.0/win length with processes. 71.28 - 72.0uin .breadth with processes, isthmus 4.86 - 6.24/u. Euplankton: Stations D, I - II4. 160 Staurastrum granulosum (Ehrenb.) Ralfs 1848 P1. 18 fig. 12 Irenee-Marie 1938, page 287. Cells 35.64 - 36.0/win length, 38.88 - 39.0/u. in breadth. isthmus 12.96 - 13.0/win broad. Tychoplankton: Station 5. Staurastrum Johnsonii'w. &‘W. 1896 P1. 1Z fig. 1 Smith 1924, page 104. Cells 53.04 - 54.60/Lin length with processes, breadth with processes 89.05 - 95.16/0, breadth of isthmus 12.48 - 14.04%t. Tychoplankton: Station D. 8taurastrum longir§81§§ym var. elevatum Fritsch & Rich 1937 P1. 1Z fig. 2 Fritsch and Rich 1937, page 209. Cells 64.80 - 79.7710in length with processes, breadth with processes 73.32 - 81.01», breadth of the isthmus 4.68 — 6.48ya. Euplankton: Stations C.D.I - II - C. Staurastrum paradoxum Meyen 1829 P1. 1Z fig. 2 Smith 1924, page 85. Cells 30.78 - 32.76/tin length with processes. 40.50 - 46.98u.in breadth with processes, isthmus 6.48 - 7.80/tin broad. Euplankton: Stations C,D,I - II - C. Staurastrum p1anctonicum Teiling 1946 P1. 12 fig. 2 Teiling 1946. page 77- Cells 51.84 - 64.80/Lin length including the processes, 85.80 - 87.4822 in breadth including processes, isthmus 11.34 - 12.2;Lbroad. Euplankton: Station D. 161 Staurastrum polymorphum de Breb. fa. Pl. l_6 fig. 8 Irenee-Marie 1938. page 306. Cells 38.84 - 40.56/bin length, 40.56 - 46.98/11. in breadth including processes, isthmus 10.92 - 12.9810broad. Tychoplankton: Stations C. 5. Staurastrum punctulatum de Breb. 1848 P1. 18 fig. Z Irenee-Marie 1938, page 284. Cells 18.72 - 20.28/bin length. 26.52 - 28.08/u in breadth, isthmus 7.02 - 7.80/Loin breadth. Tychoplankton: Station D. Staurastrgm gpebecense var. omatum Wade 1957 P1. 12 figs. 8 & Z Wade 1957. Page 269. Cells 37.44 - 46.80/win length, including processes. 48.60 - 57.72/21, breadth including processes, isthmus 9.72 — 12.48/Lin breadth. Daplankton: Stations C,D,I - II,II - III. Tychopl ankton: Stations D , l . Aufwuchs: Artificial Substrates Station A. Staurastrum sebaldii var. ornatum Nordst. 1873 P1. _1_Z fig. 2 Irenee-Marie 1938. page 309. Cells 64.80 - 65.0}.ein length including the processes, 114.07 - 115.0/4. in breadth including the processes, isthmus 13.77 - 14.04/win breadth. Tychoplankton: Station D. Staurastrum striolatum (Naeg.) Arch. 1861 P1. 11 fig. 2 Croasdale 1957, page 149. Cells 21.84 - 22.2/oin length. 24.96 - 25.Q/¢in breadth, isthmus 6.24 - 6.5ptbroad. Tychoplankton: Station D. 162 Cosmarium Corda 18 34 Cosmarium angplare var. canadense Irenee-Marie 1938 P1. 12 fig. 12 Irenee-Marie 1938, page 179. Cells 26.52 - 29.64/om diameter, 29.64 - 32.40/1,. in length, 6.24 - 8.10/u. breadth at the isthmus. New record for Michigan, previously reported from Canada. Euplankton: Stations D - I. Tychoplankton : Stations C ,D . Aufwuchs: Artificial Substrates Station A. Cosmarium ingulosum de Breb. 1856 P1. 12 fig. 12 Irenee—Marie 1938. page 177. 08115 19.44 - 20.0/win length, 13.7? - 14.04/win breadth, isthmus 4.86 - 5.0/abroad. Tychoplankton: Station 4. Cosmarium Botgytis (Bory) Meneghini 1840 P1. 12 fig. 12 Smith 1924, page 33. Cells 71.28 - 74.88pm length. 55.08 - 57.72/uin breadth, isthmus 19.44 - 23.40/win breadth. Tychoplankton: Statims C .D, 4. Cosmarium Botrytis var. mediolaeve W. a W. 1892 P1. 12 fig. Z Taylor 1934. page 251. Cells 49.92 - 51.48;.ein length. 43.68 - 45.24/4. in breadth, the breadth at the isthmus 12.48 - 14.04/w. Tychoplankton : Stations C . D. Cosmarium constr1gt81 Delp. 1877 P1. 12 fig. 12 Miller 1936. page 88. Cells 45.24 - 46.80/u,in length, 31.20 - 32.76/Abroad. isthmus 10.92 - 11.03/win breadth. Tychoplankton: Stations C,D. 163 Cosmarigg Cucumis (Corda) Ralfs 1844 P1. 13 fig. 13 Irenee-Marie 1938. page 161. Cells 38.88 - 39.0/win breadth, 58.32 - 59.28/A- in length, the breadth at the isthmus 19.80 - 21.06/w. Tychoplankton: Station 5. Cosmarium cmnatoplerum var. tyrolicugg Nordstedt 1876 P1. 12 fig. 8 West and West 1908, page 6. Cells 54.60 - 76.74/Lin breadth, 76.74 -. 78.0/win length, the breadth of the isthmus 18.72 - 20.28/u. . Tychoplankton: Station C. Cosmarium formosulum Hoffman 1888 P1. 12 fig. 2 Taylor 1934, page 253. Cells 43.68 - 45.36pm length, breadth 29.16 - 31.20/u, isthmus 12.48 - 14.58/u. in breadth. Tychoplankton: Station D. Cosmarium Frinzston11 Taft 1945 P1. 12 fig. _5_ Taft 1945, page 194. Cells 53.04 - 55.08/wbroad, 65.52 — 68.64/12in length, isthmus 20.28 - 21.30/44. breadth. New record for Michigan, previously reported from Lake Erie by Taft. Tychoplankton: Stations C . D . 3 . Cosmarium gganatum (de Breb.) Ralfs 1844 P1. 12 fig. 12 Taylor 1934. page 253. Cells 34.32 - 51.48/Lain length, 24.96 - 35.64/., in breadth, isthmus 7.80 - 10.5/ibroad. Tychoplankton : Stations C . D. Aufwuchs: Artificial Substrates Stations A,B. 164 Cosmarium granatum var. ocellatum W. 8: W. 1895 P1. 12 fig. 12 Croasdale 1956, page 36. Cells 25.74 - 26.9,u.in breadth, 34. 32 — 39.76/iin length, isthmus 6.24 - 7.10pm breadth. Euplankton: Stations III - D. Tychoplankton: Station D. Cosmarigg granatum var. subgranatum Nordstedt 1878 P1. 12 fig. _1_ Croasdale 1956, page 36. Cells 22.75 - $.08luin breadth. 29.64 - 31.5/Lin length. isthmus 4.68 - 7.4/ebroad. Euplankton: Stations D - I. Tychoplankton: Stations C,D. Cosmarium impressulum Elfv. 1881 P1. 12 fig. g Croasdale 1956, page 39. Cells 18.72 - 20.28/tin length, 14.04 - 15.60/win breadth, isthmus 4.68 - 5.0/aim breadth. Tychoplankton: Stations D, 5. Cosmarium Qelhnanii var. ornatum Wille 1879 P1. 12 fig. 12 Croasdale 1956. page 40. Cells 29.64 - 30.78pm breadth. 39.32 - 35.88/win length, isthmus 8.5 - 9. 36lubroad. Euplankton: Stations C,D - I, II4 - II. Cosmarium 11838 var. depressum Croasdale 1956 P1. 1} fig. 3 Croasdale 1956. page 40. Cells 14.04 - 17.16/min breadth, 17.16 - 20.0/min length. isthmus 3.12 - 4.68/Abroad. Tychoplankton: Stations 1), 5. 165 Comarium obtusatum Schmidle 1918 P1. _1_; fig. 3 Croasdale 1956. page 1&2. Cells 140.56 - 42.12pm length. 35.6l+ - 38.5,u.in length. isthmus 8.10 - 12.25;. in breadth. Tychoplankton: Stations D,4. Cosmarium ochthodes Nordstedt 1875 P1. 13 fig. 12 Taft 1945. Page 198. ' Cells 67.08 - 68.6upin breadth. 93.60 - 95.90;. in length. isthmus 21.84 - 23.40;; broad. chhoplankton: Station D. Comarium pachldermum Lundell 1871 P1. _1_} fig. 3 Irenee-Marie 1938. page 160. Cells 63.96 - 6#.O,un in breadth. 68.6“ — 81.12/41n length. isthmus 29.64 .- 30.0}t in breadth. Tychoplankton: Station 5. Cosmarium ghaseolus de Breb. 18140 Pl. 1}! fig. _9_ Croasdale 1956. page #5. Cells 30.78 - 31.20/win breadth. 37.1w - 38.88/min length. isthmus 8.0 - 9.72115. broad. Explankton: Stations III - D. Cosmarium pseudonitidulum Nordstedt 1873 P1. 111 fig. 19 Croasdale 1956. page I+7. Cells 32.150 - 33.0,u.in breadth. 1+3.71+ - 11.5.21pr in length. isthmus 9.72 - 12. 25pm breadth. Biplankton: Stations II - III. II - C. 166 Cosmarium pseudoornatum Eichl. et Gutw. 1894 P1. 12 fig. 3 Ruzicka 1955. page 599. Cells 30.78 - 31+.32/pin breadth. 37.54 .. “4.08/uin length. isthmus 7.80 - 9.36/um breadth. Tychoplankton: Stations C,D. Aufwuchs: Artificial Substrates Station A. Cosmarium pseudopzramidatmn Lundell 1871 P1. _1_; fig. 2 Taylor 1931+. page 261. Cells 96.12 - 99.84pm length. 7#.88 - 76.5/1-in breadth. isthmus 20.28 - 21.0,“. broad. 'mis plant differed from the species by being almost twice as large. Tychoplankton: Station D. Cosmarium punctulatum de Breb. 1856 P1. 15 fig. _8 Taylor 193“. page 261}. Cells 32.76 - 31+. 32pm breadth. 37.414 - 38.88/u in length. isthmus 11.34 - 12.148}; in breadth. Euplankton: Stations D -.I. tychoplankton: Station C. Cosmarim regaesii Reinsch 1867 P1. 15; fig. _8_ West and West 1908. page 36. Cells 7.80 - 8.0/tin breadth. 7.8 - 9.36/“in length. breadth of isthmus 4.68 — 6.0/u. Tychoplankton: Station D. Cosmarium reniforme (Ralfs) Archer 1874 P1. 1} fig. 2 Irenee-Marie 1938. page 194. Cells 39.0 - 57.72/Lin breadth. l+3.68 - 59. 28/cin length. isthmus 12.84 .- 17.l6/u.in breadth. Tychoplankton: Stations C,D. 167 Cosmarium reniforme var. compressum Nordstedt 1887 P1. 12 fig. 13 West and West 1908. page 158. Cells 1+7.0 - 48.36/Lin breadth, 53.04 - 56.16/tin length. isthmus 11+.04 - 18.72/win breadth. Euplankton: Stations D - I. Tychoplankton: Stations C,D. Cosmarium reniforme var. elevatum W. 8: W. 1898 P1. 12 fig. 2 West and West 1908. page 159. Cells 42.12 - 15.21% in breadth. 56.36 - 59.28/Lin length. breadth of the isthmus 15.60 - 16.0/u. Euplankton: Stations D - I. Tychoplankton: Station D. Coanarium subcostatum Nordstedt 1876 Pl. 1% fig. _2 West and West 1908. page 237. Cells 21+.96 - 25.0/win length. 21+.18 - 24.96/abroad, isthmus 7.80 - 8. 58,u.in breadth. Tychoplankton: Station D. Cosmarium subnudiceps W. 8: W. 1897 P1. 13 fig. _8 Irenee-Marie 1948. page 167. Cells 39.0 - 1+0.50/u.in breadth. l49.92 - 56.861; in length. isthmus 12.96 - may. broad. New record for Michigan. Euplankton: Stations II - C. Tychoplankton: Stations C,D. Cosmarium subtumidum Nordstedt 1878 P1. 13 fig. 3 Irenee-Marie 1938. page 167. Cells 43.68 - h6.80,u~in length. 32.76 - 34.32am breadth, isthmus 9.36 - 10.92/win breadth. Tychoplankton: Stations C,D. 168 Cosmarium sulcatum var. sumatranum Schmidle 1901 P1. 1} fig. _6_ Taft 1916. page 200. Cells 31.2) - 37.0,» broad. 45.214» .. 146.80% in length. isthmus 9.36 - 10.92,“ in breadth. This plant is placed here with a question because it is larger than the measurements given for this species and not enough material was seen. Tychoplankton: Station D. Cosmarium tetraophthalmum de Breb. 18’48 P1. 15 fig. 3 West and West 1908. page 270. Cells 71.76 — 75.5h/pin length, 61.52 - 62.40/...in breadth, isthmus 23.40 - 24.96/abroad. Tychoplankton: Station D. Cosmarium Tuginii de Breb. 1856 P1. 13 fig. 1 Irenee-Marie 1938. page 199. Cells 68.61} - 69.0/‘9111 length. 56.70 - 57.72/ubroad. isthmus 16.20 - 17.16/“in breadth. Tychoplankton: Stations D,1, 2. 3. 5 . Cosmarium vexatum West 1892 P1. 12 fig. 11 West and West 1908. page 187. Cells [+3.68 - “4.0/um length. 37.44 — 39.0/4 broad. isthmus 10.92 - 11.0/min breadth. Tychoplankton: Station C. Cosmarium vexatum var. rotundatum Messik. 1942 P1. 13 fig. 3 Messikonmer 19%. page 159. Cells 42.12 - I+3.68,I.4.in breadth. 146.80 - 56.16/win length. isthmus 12.48 - 13.0,,Lbroad. Tychoplankton: Statims C,D. 169 Cosmarium Wittrockii Lundell 1871 P1. 12 fig. 2 West and West 1908. page 179. Cells 20.28 - 21.84/u. in length, 20.28 - 21.81%. broad. isthmus 16.38 - 17.0}; in breadth. This plant resembles var. guasidepressum Skuja. Tychoplankton: Stations D. 5. Cosmarium Ungerianum (Naeg.) De Bary 18119 P1. 12 fig. 1 West and West 1908. page 195. Cells 140.56 - 1+2.12,o.in breadth. 53.04 - 5h.60/..in length. isthmus 14.04 - 15.60/abroad. Cells slightly smaller than typical. Tychoplankton: Station D. Cosmarimn sp. A P1. 12 fig. 19_ Cells 32.76 - 16.7me breadth, 43.68 - 53.146/win length. isthmus 9.36 - 12.96;... broad. This plant resembles _C_. gymatOpleurum var. Tyrolicum Nordst. Tychoplankton: Stations C,D. Cosmarium sp. B P1. 12 fig. _11 Cells 28.08 - 29.6li/u.in breadth. 3l&.32 - 35.88/min length. isthmus 7.80 - 8.0/abroad. Tychoplankton: Station D. Cosnarium sp. C P1. 12 fig. 6 Cells 39.0 - 40.0/u-in breadth. 1+0. 56 .. 1+2.12/u,in length, isthmus 14.04 - 15.60/kin breadth. This plant resembles _C. subreniforme Nordst. Tychoplankton: Station C. 170 Cosmarium sp. D P1. 12 fig. _9_ Cells 28.08 - 29.6h/bin breadth. 28.08 - 29.6h/1in length. isthmus 9.36 - 10.0,wbroad. Tychoplankton: Station D. Cosmarium sp. E P1. 1}! fig. 11 Cells 31+. 32 - 35.88/win breadth. z40.56 - 42.12/“in length. isthmus 14.01! - 15.0/i—in breadth. Tychoplankton: Stations C . D . VIII. PLATES 171 172 PLATE 1 Chroococcus turgidus var. maximus ..................... Chroococcgs turg1dus .................................. Chroococcus limneticus var. subsalsus ................. Chroococcus dispersus ................................. Chroococcus limneticus var. distans ................... Merismgpedia elegans .................................. Merismopedia glauca ................................... Merismgpedia punctata ................................. Merismgpedia tenuissima ............................... Chroococcus vafius 00............OOOOOOOOOOOOOOOOOO.... Gloeothece rgpestris ....................:............. Merismopedia consoluta ................................ Rhabdoderma irregulare .... Gomphospaeria aponina .. Coelosphaerium Naegelianum ............................ Coelosphaerium Kuetziggianum .......................... Chroococcus limggticus ................................ Gomphospaeria aponina var. multiplex .................. Fig. 1 \OCDVOKJI-PWN 10 11 12 13 1h 15 16 17 ,w ,——-,-. m~m,_‘ _ —_.-* FLA?! ' I . 0 g “4. IT \ 7er II 3.1 a l a 0...--. a m1 8 Am... \.. .-.-.. as. 3 .. _. 9.1”. s is. 39383 r... as... an? 35% a” 30 C. a 4...... .ur. gm 4..-: Q? 0@ 0m... t as... ...... mass is 8% \w. .§ :3 09.3., Om . goon? 000 00 0;, 0000030 0.28 0° 00 00 PLATE 2 Fig. H FlicrOQyStis incerta 0.0.000...0............OOIOOOOCOOOO Microcystis aeruginosa ................................ Microcystis flos-aquae ................................ AphanOthece microsgora ......OOOOOOOOOOOOOOOOO0.0.0.... fiphanothece castagnei ................................. ABhanOthece elaChiSta 0.00.0.0...OOOOOOOCOOOOOOOOOOOOO. Marssoniella eleggns 00.000.000.00.......OOOQOOOOOOOOO. Aphanocafis-a fimaris ......OOOCOOOOOOOOCCOOOO....O.... \OCDVOU‘FWN ABharloulece Stagnina .....OOOOOOOOOOOOOOOOOOOOOOOOOOOO. LisngEaBirgei ......OOOOOOOOOOOO0.0000000000000000.... lo Lingbiamggetii O00......00.000.000.00...0.0.0.000...Oll Liizngma merWUSii ......OOOCOOCOOOOOOOOO00.0.0000... 12 Mmajor ... 13 _P‘fl PLATE' 2 lllllll‘ll-l—llHHHIHIMHHIHIllllHHll I .. H" l3 PLATE 3 Fig. H Atlabaena SUbCYI‘Edrica 0.0.0.0000......-......OOOOOOOO. Anabaena SCheremetieVi oooeoeeeoeeeeeeeooeoeeeeooeooooo Anabaema catenula ..................................... Anabaena macrospora var. robusta ...................... Anabaena CirCinali-S 0.0.00.0........OOOCOOOOOOOOOO0.... §Eirulma gigantea 00.0.0.......OOOOOOOOOOOOCOOOOO0.... Arthrggpira Jemeri ......OOOOOOOOOOOOOOOCO0.0.0.000... Oscillatoria pringgps ................................. \O (D ‘Q (h \n {T b) h) MicrOSCOJ-eus lacuStriS OOOOOOOOOOOOOOOO......OOOOOOOOO. OSCillatoria sancta 00.0.0.0.........OOOOOOOOOOOOOOOOOO 10 SEirlllj-rla Erincees 0.0.0.0...0.00....OOOOOOOOOOOOOOOOOO ll OSCfl-latoria tenuis 0......0.0.0.0..........OOOOOOOO... 12 OSCillatoma amoena......OOOOOOOOOOOOOOOOOOOOOOOOIOOO. 13 PLATE '3 :C_::::ju 178 PLATE h L‘IZ-l'gbia aestuarii ......OOOOOIOOOOOOOOOOO0.00.00.00.00. Lyngbza aerugineo-caerulea ............................ Lizngia Lagerheimii ......OOOOOOOOOOOOOOO......OOCOOOO. LZZEEbEa Erie—11316113. 00.0.00.........OOOOOOOOOOOOOOOO0.. calOthrjx SCflonemiCOla 0.0.000........OOOOOOOOOOOOOOO. T01flothfix lubata ......OOOOOOOIOOO......OOOOOOOOOOOO scytonana criSPm ......OOOOOOCOOOOCOO......0.0.0000... TOJJPOthrix tenus ......OOOOOOOOOO0.0.0.000...00...... calOthrix parietirla 0.0.0..........OOOOOOIOOOOOOOO....0 Fig. 1 \OGJNJChKn-F'KDN Plectonema nostocorgm_...............................,. 10 calOthrix fusca O..OOOOOOOOOOOOOIOO0.0000000000000IO... 11 calOthrix Braunii 00.00.000.000.0000000000000000.00.... 12&13 calOthm caStellii ......OOOOOOOOO......OOOOOOOOOOOOOO 11+ PLATE" 4 PLATE 5 Tribonema minus 0.0....00.00....00.000000000000000... TI‘ibonema utI'iCUIOSum ecoeeooeooooooooeeeooeeeoeoeoeo Tribonema bOMCinm .........................oooo.o.. 92011th111!“ COChleare .....OOOOOOO0.0.000.000.00000.0 ophiocytim mains 0.0.000...OOOOOOOOOOOOOOOOOO0...... Qphioqytium graci1ipes .............................. wiocytillm desertmn 00.00.00.000.......OIOOOOOOOOOOO _vauCheria ggminata .....OOOOOOOOOCOOOOOOOOOOOOOOOOOO. DjnOnyon Ellindriclm 0.0.0.......OOOOOOCOIOOOOOOOOOO E \o (n ~o Ch kn {r u) A) F’ Dinobl'yon5001ale....o.........................o...o 10 Dinobnyon divergens ................................. ll Tribonma utrj-CIIlosmn ......OOOOOOOOOOOOOOOOOO0...... 12 DinObmon Sertflaria ......OOOOOOOOOOOO......OOOOOOOO 13 >.* “A ~_ “*‘u ~—-—_, PLITE'G PLATE 6 Fig. PmfifinflmVfiuei.n.u.u.u.u.u.u.u.u.n.u.. 1 'Eggid1gigm Vblzii ................................... Eggig1n1pm umbonatum ................................ Peridinium gnconspicuum ............................. \anm Peridinimn 1231ng seeoeeeeoeooeoeoeooeeeeoooeeeoeoeoeo ceratim himndifiilé 000.000.000.00000000000000000.06 8; 7 PLATE ' 6 184 PLATE 7 Fig. Phacus contortus var. comp1icatus; D is a bottom view.. 1 Phacus rudiCLI-la 0.00......00...........OOOOOOOOCOOCIOO 2 Phacus_ gigas 0....000......000000000000.00.00.00.00... 3 Phacus lismoren81s 00............OOOOOOOOOOOOOOO....O. 1+ Phacus longicauda var. insecta .................... 5 & 6 Phacus longicaUda 00.0.0000......OOOOOOOOOOOOOOO... 7&8 Phacus tor-bus 0.00.00.00.00........OOOOOOOOOOOOOOOOOOO 9 I'fi —_- § ‘—_-_—_-—_‘n_—_.n___-———‘ ca“— ¢A_‘—-r_‘ — ’-—A.4 PLATE‘ 7 . .... a Ion-v.14i-II'IcO’Oe Ol.0of. 407.. ... . {fix ,I. . . 24100.», c I...“ I I 0' IO. III-IO I ‘0'..- a ‘n ...-100.--...- a. ‘ ouoIlottl 3| 0 ' o a. 1‘... a . C . .. noes-On 0- I .[ol-le-o ,. can... no” ...-'8': 186 PLATE 8 orbicularis ......COOOOOOOOOOOOOO0.00.0.0000... orbiC'lllaris fa. 000............OOOOOOOOOOOOOOOO acuminatus eeoooeeoeeoeoeeoeeeooeeeeoeooeoeoeeo pleuroneCtes eeeeooeoeeeeeeeeeoooeoeoeoeeeeeeee caudatus 0.0......OOOOOOOOOOOOOOOOO0.00.0000... setosus 0.0.0..00.0.0.0...00.000000000000000... Llatalea 0........................OOOOOOOOOOOOO pseudOSW’irenkoi eoeoeoeeooeoeoeeeeeeeeeeeooeeoo Sp. E 0.0.0.0...00............OOOOOOOOOOOOOOOOO sp. D.0...0.00.0...00.0.0.......OOOOOOOOOOOOOO. unguis O...0.0I.........OOCOOOOOOOOOOO0.0.0.... undulatus eeooeooooeeeooeoooboeeeeeeoeeoeeeeoee Mlonaton ...0.0.0.0.........OOOOOOOOOOO0.0.0 sp. F ......................................... sp. A ......................................... sp. B ......................................... sp. G ......................................... lonfiicallda Var. major so.00000000000000.0000... Sp. C......O........OOOOOO.........OOOOOOOOOOO Fig. mummtwm 11 12 13 14 15 16 17 18 19 h "-fi‘.-'—.——4t‘___-‘q——g._—!g“_W"nfl—N-v—‘Afi‘ -..E:——-—-‘-..———-—a— 1‘ —-————A*‘ PLATE ’0 188 PLATE 9 LepOCinCI‘jfi om 00.000.00.00.........OOOOOOOOOOOOOOOO malena Sp. ...-.0000.........OOOOOOOOOOOOOOOOO0...... Euglena omris Var. minor eeeeeeoooeeeeeooeeeeoeeeeee mglena acus 0.....0OOOOOOOOOOOOOOOOOOO00.00.00.000... TraChelomonaS WwShi ......OOOOOOOOO......OOIOOOOI. iaChelomonas hiSpj-da O......OOOOOOOO......OOOOOOOOOOO Trachelomonas hispida var. dgplex .................... TraChelomonaS pUlCherrima oeeeoeeoeeeeooeeeeeeeeeeecoo TraChelomonaS CJYlindriCa eeeeeoe00000000000000.0000... Trachelomonas australica var. rectangularis .......... Trachelomonas bulla .................................. Trachelomonas p1anctonica var. oblonga ............... Trachelomonas obovata var. klebsiana ................. Trachelomonas volvocina .............................. Trachelomonas splendidissima ......................... Trachelomonas volvocinopsis var. punctata ............ Anisonema sp. ........................................ Phacus sp. H ......................................... Phacus Sp. I eoeeeooeeoeeeoeeoeeeeeeoeoeoeeeeeeeoeeooo cmmomonas pSGUdoperifi oases...00.000000000000000. Eldor'ina Elggang oeeeeeeeeeooooeeeoeeeooeooeeeoooso... Fig. CDVQUCWN“ 00 11 12 13 14 15 16 17 18 19 20 21 ‘ ~— ~ ‘q'—‘-h l“.-.-"—’ ~""'4III= a ...—W .. .....- ’._ ." ... A “ ... *“ A4; PLATE-'9 190 PLATE 10 Scenedesmus abundans ................................ Scenedesmus arcuatus var. platydisca ................ Scenedesmus blluga eooeeeeeeeoooeooeoeoooooooooooeeee Scenedesmus guadficaUd‘ oooeooeeeeeeeooeeeeooeeoeeeeo Scenedesmus ggadricauda var. quadrispina ............ Scenedesmus armatus ................................. Scenedesmus dimorphus eoeeeocooeeooeoooeeeeeeeeeeoeeo Scenedesmus Obliguus eoeeooeeoeeeeoeeeeooeeeeeeooooeo Scenedesmus LuadricaUda var. 28m oeeeeeooeeeoeoeoo Scenedesmus Obliguus eeeeoeeeeeeee00000000000000.0000 Tetradesmus wisconsinense ........................... GOIaninj-a radiata 0.0.0.0000.........OOOOOOOOOOOOOOO Dictyosphaerium pulchellum .......................... Kirchneriella Obesa eoeeeooeeee00000000000000.0000... Kirchneriella lunaris ............................... Kirchnerie11§ contorta .............................. Nephrocytium Agardhianum ............................ Oocystis 51533 ...................................... NephI‘OCltium Obesum oeeoeoeoeeeeeoeeeeeeeeoeoooeeeeee Botgyococcus Braunii ................................ Fig. \OCD\IO\\A\D 10 11 12 13 11+ 15 16 1? 18 19 & 4 ”dB-_— ‘ *fl**—*-— h_~—_a——_-—_—— PLATE“ IO 192 PLATE 11 Fig. PediaStrum duglex ......OOOOOOOOOOOOOOOI.0.0.0.0... 1 Pediastrum duplex var. clathratum ................. 2 Pediastrum Boryanum ............................... 3 Pediastrum Boryanum var. longicorne ............... 4 Pediastrum tetras ............................. 5 & 6 Pediastrum Boryanum fa. ........................... 7 Pediastrum Bogzanum fa. ........................... 8 Pediastrum simplex var. duodenarium . . . . . . . . . . . . . . . 9 Pediastrum integrum var. pgrforatum fa. ........... 10 ——u;_—fl-_—fl__.—_~ “*——-—_——_ 194 PLATE 12 QmmigdaCMflmdi.u.u.u.u.u.u.n.u.u.u. Dispora crucigenioides ............................ Micrasterias sol .................................. Euastrum insulare var. basichondrum ............... Euastrum insulare ................................. Euastrum hypochondrum fa. decoratum ............... Euastrum Turneri fa. .............................. Penium marggritaceum .............................. Pleurotaenium Ehrenbeggii ......................... Fig -‘ CD\JO\U'I$'\JN 9 Pleurotaenium trabecula ...................... 10 & 11 Cosmarium an are var. canadense ................. 12 Cosmarium angulosum ............................... 13 coma—rim granatm 0.00.0000.........OOOOOOOOOOO...11* Cosmarigm granatum var. ocellatum ................. 15 PLM'l! Cosmarium 1 6 \ O PLATE 13 granatum var. subgranatum ............... Cosmarium illpreSSUlm 00.000000000000000.0.00.0000. Cosmarium 1aeve var. dgpresggm .................... Cosmarium paChydemm 00000000000000.0009.oeeeeoeoe Cosmarium Cosmarium WittrOCkii eeeeeeeoeeoeoeooeoeeeoeeeeeeoo sulcatum var. sumatranum ................ Cosmarium reniforme oeeooeeoeooeoooeeeeeeooeooeoeeo Cosmarium Cosmarium Subnudiceva— ......OOOIOOOOOOOOI0.0.0.0... reniforme var. elevatum ................. Cosmarium Cosmarium Cosmarium 54161117131111 var. ornatum eeooeeeeeeeeoeoee vexatum oeeooeooeeeeeeeeeeeoeeoeeeeeeeoee cuccmis 00............OOOOOOOOOOOOOOOOOO Cosmarium Cosmarium gpniforme var. compressum ............... conStriCtm ......OOOOOOOOOOOOOO000...... Fig. mummtum 1o 11 12 13 14 “fl _‘n- _-——— _—_-—_—_—_ _ —fl fl —-_.—-_—-__.— —-—._ PLATE' 13 Cosmarium Cosmarium Cgsmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium Cosmarium 198 PLATE 14 Turpinii ................................ subtumidum .............................. vexatum var. rotundatum ................. phaseolus ............................... Franzstonii ............................ gymatgp1eurum var. tyrolicum ............ Botrytis var. mediolaeve ................ rggnesi ................................. subcostatum ............................. pseudonitidulum ......................... sp. E. .................................. ochthodes ............................... kmtis 00............OOOOOOOOOOOOOOOOO Fig. CDVONU'I-l—‘wN 9 1O 11 12 13 PLATE' l4 .ooO boo s..mo Cosmarium 200 PLATE 15 Fig. H tetmphthallnug 000000000000000000.0000... Co sm arium Obtusatum oeeeeeeeeeeoeeeooeeeeeeeeeeeeee Cosmarium fomOSUIm 0000.00.00.000000000.0'00000000 Cosmarium pSCUdoomatmn 000.000.00.0000000000000000 Cosmarium pgeudopflamidatum ....................... Cosmarimn Co smarium Sp. c.00000.0000.00000000000000000.0000. uggprlanug eecoeoeeeeoeoeoeeeoeoeeoooeeoe Co sm arium punCtUIatnm 00.000000000000000...oooeooee Cosmarium Co smarium Cosmarium ‘0 (D \J O\\fi -P \0 h) sp. D00000000000000000.0000.00000000.... Sp. A0.000000000000000000000000000000000 lo Sp. B0000000000000000.000000000000000000 ll ClOSterium gamut“ 00000000000000...000000.00 12&13 ngSterium incurvum eeeeeoooeoeeoeeeeeeoeeeeoeeoooo 14 ClOSterium sublaterale 00000.000.00.000000000.00... 15 ClOSterj-m Strigosmn 0.000.000.000000.000.000.00... 16 ClOStérium acerosum 00000000000006.0000...ooooeooeo l7 PLATE-” 202 PLATE 16 Fig. Closterium pgeudolunula ....................... l & 2 §1osterium acerosima var. 13g1§gm ................ 3 Closterium Leibleinii ............................ Closterium moniliferum ........................... Staurastrum polymorphum ...................\....... Staurastrum punctulatum .......................... Staurastrum floriferum ........................... \O(D\10\\J\£: Staurastrum chaetoceras .......................... Staurastrum granulosllm 00000000000000000000000000. lo StauraStrum bienneanum var. elliRtiCUIn eee 0.0000000 11 StauraStm Brebissonii esoeeeeoeeeoooooeoooooeoeo l2 PLATE' I. Staurastrum Stagrastrmn Staurastrum §Eaurastrym Staurastrmn Staurastrmn Staurastrum PLATE 1? Fig. Johnsonii ............................ 1 paradoxum ............................ 2 striolatum ........................... 3 longiradiatum var. elevatum .......... 4 disputatum ........................... 5 qggbecense var. ornatum ........... 6 & 7 Elmetonicm 0.00000000000000000.00.00 8 Staurastrum SCbaldii var. omatum 00.00.000.000... 9 PLATE-" 206 PLATE 18 Stigeoclonium tenuis ............................. Stigeoclonium flagelliferum ...................... Tetraedron enorme fa. ............................ Tetraedron minimum ............................... §phaerogystis Schroeteri ......................... Tetraedron trigpnum var. gracile ................. Tetraedron tumidulum ............................. Tetraedron trigonum .............................. Fig. CDVOU‘FKDN PLATE‘I. 208 PLATE 19 Ulothrix tenerrima ............................... Microspora elegans ............................... Cylindrocap§a geminella .......................... Dungmhmfwhgflwhfii.u.u.n.u.u.n.n.u.. Oedoggnium g1obosum .............................. Spiroggra Porticalis ............................. Draparnaldia glomorata ........................... PLATE“ I9 |I“ fl H - ...§. <<¢ '4. IX. BIBLIOGRAPHY Ball. R.C. and Party. 1938. A Report for the Institute of Fisheries Research. Michigan quartment of Conservation. Behning, A.L. 1924. Zur Erforschung der am Flussboden der wolga Lebenden Organismen. Monogr. d. Biol. wolga- Stat. Nr.l Birge, E.A. and Juday. C. 1922. The Inland Lakes of Wisconsin. Wisconsin Gaol. and Nat. Hist. Sur. Wisconsin. Bull. 64 No. 13. Chandler. D.C. l9h0. Limnological Studies of western Lake Erie. I. Plankton and Certain Physical-Chemical Data of the Bass Island Regions from Sept. 1938, to Nov. 1939. Ohio Jour. Sci. no: 291-236. (reprint) Cooke,'W.B. 1956. Colonization of Artificial Bare Areas by Micro- organisms. The Bot. 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