STUDIES ON THE LIFE HISTORY or me YELLOW mm. mm FLAVESCENS (MITCHILL) :N I BIG BAY DE Mac,- LAKE MICHIGAN Thesis for I'M Degree of M. S. MICHIGAN STATE UNIVERSITY Robert .oneph Toth 1959 1| mm; IIZIIIJILHIIII In I I I II “III [III I L TH SSSS L IR R .4 R Y Michigan State University ‘. 3E g2" & 3" .' -' . q I l v. .V‘ . ~ I. -‘v ...&\_.., ‘V VI&, . l 3E? '4 6 1994. . ~STUDIES ON THE LIFE HISTORY OF THE YELLOW PERCH, PERCA FLAVESCENS (MITCHILL),IN BIG BAY DE NOC, LAKE MICHIGAN By ROBERT JOSEPH TOTH AN ABSTRACT Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1959 Approved__{M77.€4:¢-é‘/.?20%___-___--__ ABSTRACT The yellow perch, Eggga flavescens (Mitchill), is an important food and sport fish in the Big Bay de Noc area of Lake Michigan. Between 10 and 30 percent of the total annual commercial catch in Lake Michigan comes from the waters of Big Bay de-Noc. \ This study/is based on 1095 specimens collected in- 1957 and 1958 by gill-nets from five sample areas in Big Bay de Noc. Of these specimens, 1045 were used in the calculation of previous growth. The body-scale relation- ship was determined and the computed intercept was used in calculating growth histories. Analysis of the length- weight relation was based on 592 specimens taken during July, 1958. Calculated lengths at a given age were consistently larger in the older fish. It is felt that these discrep- ancies were due in part to inter-specific competition. There were no major differences noted in growth rates be- tween the sample areas. The growth of males and females was disproportionate, with the females maintaining a slight length advantage. There were no differences in the condition factor for males and females. Both sexes required five years of growth to reach the legal commercial size of 8% inches. Mayflies, crayfish, aquatic isOpods, amphipods, and midge larvae were the food items most frequently encoun- tered in analysis of stomach contents. The incidence of parasitism in the yellow perch of Big Bay de Noc is extremely light. Only four species of internal parasites were recorded. The relative abundance of perch in Green Bay in 1958 is at a peak level, and the degree of inter-specific com- petition it is subjected to will determine in part whether this high level of abundance can be maintained. STUDIES ON THE LIFE HISTORY OF THE YELLON PERCH, PERCA FLAVESCENS (MITCHILL), IN BIG BAY DE NOC, LAKE MICHIGAN By ROBERT JOSEPH TOTH A THESIS Submitted to the College of Agriculture of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1959 ACKNOWLEDGEMENTS I extend sincere gratitude and thanks to Dr. Eugene W. Roelofs under whose able guidance this study was car- ried out. I also extend thanks to Dr. Philip J. Clark for assistance in the statistical analyses of the data; Dr. David T. Clark for advice and assistance in the prepara- tion and identification of parasites; Dr. Peter I. Tack and Dr. Robert C. Ball for their help in biological prob- lems; and Messrs. Terry and Gary Roelofs who assisted in the collection of field data. This study was financed by a grant from the Michigan State University Agriculture Experiment Station through a graduate research assistantship. ii TABLE OF CONTENTS INTRODUCTION . . . . . . . . . . . DESCRIPTION OF AREA. . . . . . . . METHODS AND MATERIALS. . . . . . . Collection of Specimens . . . Individual Fish Measurements. Age Determinations. . . . . . BODYASCALE RELATIONSHIP. . . . . . LENGTH-WEIGHT RELATIONSHIP . . . . AGE AND GROWTH . . . . . . . . . . Growth in Length of Age-Groups. . . General Growth History. . . . DisprOportionate Growth of Sexes. . Growth Histories in Sample Areas. . Comparisons of Growth with Other Great Lakes. . COEFFICIENT OF CONDITION . . . . . . . . . . . . . . Comparisons of Condition with FOOD HABITS. . . . . . . . . . . . PARASITES. . . . . . . . . . . . . RELATIVE ABUNDANCE . . . . . . . . SUMMARY. . . . . . . . . . . . . . APPENDIX . . . . . . . . . . . . . LITERATURE CITED . . . . . . . . . .111 Other Great Lakes Page \.O\0\O-P ll 13 26 52 52 56 39 45 49 56 59 65 66 7O 85 Table l. 2. 5. 10. ll. 12. LIST OF TABLES Collections of Yellow Perch from Sample Areas in Big Bay de Noc . . . . . . . . . Covariance Analysis of Body-Scale Relation- ship of Yellow Perch from Major Sample Areas 0 O O O O O O 0 O O O O O 0 0 O O 0 Covariance Analysis of the Body-Scale Re- lationship of Yellow Perch from Gray's Springs and Garden Bluff. . . . . . . . . Analysis of Covariance Between Linear and Curvilinear Regressions of Body—Scale Re- lationships for all Samples . . . . . . . Length-Weight Relationships of Yellow Perch Pbpulations in Different Great Lakes. . . Calculated Total Length at the End of the Different Years of Life for Yellow Perch (Sexes Combined) from Big Bay de Noc. . . Calculated Total Length at the End of the Different Years of Life for Female Yellow Perch from Big Bay de Noc Collected During July’ 1958. O O O O O O O O O O O O O O 0 Calculated Total Length at the End of the Different Years of Life for Male Yellow Perch from Big Bay de Noc Collected During July, 1958. o o o o o o o o o o o o o o 0 Growth in Length of Yellow Perch from Dif- ferent Localities of the Great Lakes. . . Growth in Weight of Yellow Perch from Dif- ferent Localities of the Great Lakes. . . Analysis of Variance Between "KTL" Values of Sample Areas and Sexes . . . . . . . . Multiple Range Test to Determine the "KTL" Values of Male Yellow Perch not Signifi- cantly Different Between Sample Areas . . iv 0 Page 10 16 2O 25 50 55 4O 41 46 48 51 52 Table Page 15. Multiple Range Test to Determine the "KTL" Values of Female Yellow Perch Not Sig- nificantly Different Between the Sample Areas 0 O O O O O O O O O O 0 O I O O O O O 55 14. Frequency Distribution of Food Items in Stomachs of 247 Yellow Perch, Expressed as Percentage of Stomachs in Which Various Items were Found. . . . . . . . . . . . . . 57 15. Production in Thousands of Pounds Abun- dance and Fishing Intensity of Yeilow Perch in the State of Michigan Waters of Green Bay, 1945-1957. c o o. o e o o o o e o o o o 64‘ APPENDIX A. Calculated Total Length at the End of the Different Years of Life for Yellow Perch from the Different Sample Areas . . . . . . 71 B. Description of Duncan's Multiple Range Test 80 LIST OF FIGURES Figure ' Page I. Big Bay de Noc, showing sample areas . . . . 5 II. Linear regression of body-scale relation- ships as determined for the four sample areas. 0 o o o o o o o o o o o o o o o o o 0 17 III. The linear and curvilinear relationships of body length to scale radius; determined using the combined data for all sample areas. 0 O O O O O O O O O O O O O O O O O O 21 IV. The length-weight relationship of 592 yellow perch from Big Bay de Noc. . . . . . . . . 28 V. General growth in length and annual incre- ment in length of Big Bay de Noc yellow perch collected during 1957 and 1958 . . . . 57 VI. General growth in length and annual incre- ment in length of Big Bay de Noc yellow perch collected during July, 1958. . . . . . 42 vi INTRODUCTION The yellow perch, Peggg flavescens (Mitchill) is one of the important food and sport fishes found in the United States. It is soundly established throughout the north- eastern sections of the country as well as in southern Canada. It is found in great abundance in all of the Great Lakes except Lake Superior, and contributes signifi- cantly to the economic status of the states bordering on the Great Lakes. Despite its wide range, commercial pro- duction of perch is largely concentrated in three general areas; the western part of Lake Erie, Saginaw Bay in Lake Huron, and the Green Bay area of Lake Michigan.- In Lake Michigan alone, the commercial catch of yel- low perch has, over the past thirty-eight years, averaged 500 thousand pounds per year. A record catch of 1,012,000 ‘ pounds was taken from this lake in 1955 with an economic value estimated in excess of 112,000 dollars (Michigan Department of Conservation Biennial Report for the years 1955-1956). The yellow perch ranks fifth in terms of com- mercial value, and fourth in total weight production in the commercial fishery in Lake Michigan. Smelt, chubs, and lake herring, in that order, are the three species having a higher total annual catch. - 1 - The economic value of the perch as a sport fish can only be estimated, but it is known that in many localities the catch of perch by the sport fishery is in excess of the recorded commercial catch. Big Bay de Noc is one area of Lake Michigan that sup- ports an extensive population of yellow perch. This p0pu- 1ation contributes substantially to the total lake produc- tion of perch. The towns of Garden, Fayette, Fairport and Isabella are the primary fishing ports for the bay. In 1956 and 1957, Big Bay de Noc alone produced 17% am 50%, respectively, of the total poundage of perch caught com- mercially in the waters of Lake Michigan (Catch Records of the Michigan Department of Conservation). Since the yellow perch of Bay de Noc has contributed a major portion of the annual catch over a period of thirtybeight years, it was deemed necessary to investigate the present status of this exploited species to uncover any significant changes that may have occurred as the re- sult of exploitation or biological occurrences. The objectives of this present study were: (a) To determine, by comparisons with previous reports, whether the yellow perch of Big Bay de Noc constituted a stable population in so far as growth and relative abundance are concerned after being under exploitation for the past 3 thirty—eight years; (b) To determine what biological effect the virtual elimination of the Whitefish, Coregonus clupe- aformis, and the lake trout, Salvelinus nama cush, from‘ the biomass had on the present stock of yellow perch. Few studies have been made of the yellow perch in the Great Lakes. Hile and Jobes (1941) reported the growth rate of perch from Saginaw Bay, Lake Huron; while Jobes (1952) published a detailed life history of the perch in Lake Erie. El-Zarka (1958) made a recent extensive study of the pOpulation structure and growth of perch in Saginaw Bay. A paper was published in 1942 by Hile and Jobes con- cerning the growth rates of yellow perch in the Wisconsin. waters of Green Bay and waters of northern Lake Michigan. The results of this study will be compared primarily with the findings of Hile and Jobes to determine the changes in the status of the yellow perch stock in Big Bay de Noc. The changing concepts of fisheries research in the Great Lakes have been well described by Hile (1955): "The principal accomplishment of fishery biology in the Great Lakes, then, has been to teach us that for more effective understanding we must focus our attention on how fish live together in a constantly changing environment. Circumstances may require that we study species individually, and we may never achieve the goal of simultaneous research on every variety in a population; but we must never think in terms of one species alone, for it does not live alone." With these important concepts in full view, this study was undertaken. DESCRIPTION OF AREA Big Bay de Noc is a large bay extending north from the mouth of Green Bay in Lake Michigan. It has a length of 20 miles, a maximum width of 8 miles and an average depth of approximately 27 feet. Most of the shoreline of the bay is heavily wooded, mixed hardwoods and softwoods being the predominant cover type, with localized stands of pine and cedar occurring in lesser abundance. The bottom type of the northern half of the bay is send. Rock and rubble are the major bottom types of the southern shores and shoals, with loose peat and silt in the deeper areas and in the smaller coves and bays. Aquatic plants are sparse and confined to a few sheltered areas. Sampling Areas Because of limited time and funds, the whole of Big Bay de Noc could not be sampled randomly. Therefore, areas were chosen for samples which would demonstrate the char- acteristics of the yellow perch comprising the commercial catch and also areas which were easily accessible. See Figure l. l. Nahma Flats is an area utilized to a great extent by commercial fishermen. It consists of a shoal in the middle of the northern end of Big Bay de Noc. _ 4 - Figure I. Big Bay de Noe, showing location of sample areas. s1: SAOUES Z s NAHMA g 0 5 u 2 a? .. C) O 6 Q 5 4 3) ‘(x GARDEN Q A , FAYETTE C SAC BAY \ FAIRPOR LEGEND g I NAHMA FLATS 2 KATES EM 3 GARDEN an L mules I 4 GRAY'S SPRING o 3 6 5 PUFFY BAY s GARDEN BLUFF 7 2. Kates Bay is also under heavy exploitation by com— 4. 5. mercial fishermen. It is located on the east shore and specimens were taken at the mouth of the bay in 12 to 18 feet of water. Garden Bay, extending eastward from Gray's Springs, is closed to commercial fishing throughout the year. It was the only sample area with a bottom type consisting of silt and peat. Beds of sub- merged aquatics were in evidence throughout the shallow end of the bay. Samples were obtained free depths of 5 to 6 feet. I Gray's Springs was chosen for its unusual physi_ cal characteristics. A large flow of cold water enters Garden Bay over a 50 foot section of ex- posed shoreline. Large mats of green algae cover the bottom and extend out into the bay for a dis- tance of more than 100 feet. Numbers of yearling fish were noted here and the area provided the only specimens of this age-group taken throughout the entire sampling period. Puffy Bay is a small, shallow bay just east of, and sheltered by, Garden Bluff. Samples were taken from depths of 8 to 12 feet. Garden Bluff is situated just south of the mouth of Garden Bay. It is characterized by a steep shoreline droP-off to approximately 50 feet and strong shifting currents. Nets were set in depths of 9 to 15 feet and 55 to 40 feet of water. MATERIALS AND METHODS gellgction of Specimens The study of the yellow perch of Big Bay de Noc was based on a total of 1095 specimens taken from the six sample areas. See Table l. The 1957 Kates Bay sample, the May,l958 samples from Garden Bluff and Nahma Flats, and that sample taken from Garden Bay in November,l958 for parasitological examina- tion were obtained from commercial fishermen using stand- ard Zfi—inch mesh gill-nets. The two samples from Gray's Springs were taken by hook and line. All other fish were caught by means of 125-feet experimental gill-nets having a stretched—mesh size graded from 2 inches to 5% inches. These experimental gill-nets were set at an angle of 45° to the shoreline as it was felt that this position would catch fish moving in and out of the shallow water as well as fish moving parallel to the shoreline. Individual Fish Measurements The total length, in millimeters, of each fish was taken on a standard measuring board by compressing the lobes of the caudal fin to give the greatest possible measurement. All lengths given in this thesis are total lengths unless otherwise indicated. - 9 - Table l 10 Collections of Yellow Perch from Sample Areas in Big Bay de Noc Date Area Number of Fish January 29, 1957 Katee Bay 405 May 25, 1958 Nahma Flats 51 May 25, 1958 Garden Bluff 55 May 24, 1958 Garden Bluff 85 July 9, 1958 Puffy Bay 46 July 10, 1958 Garden Bluff 69 July 11, 1958 Garden Bay 28 July 12, 1958 Gray's Springs 61 July 15, 1958 Kates Bay 86 July 15, 1958 Gray's Springs 12 July 15, 1958 Katee Bay 51 July 16, 1958 Garden Bluff 100 November 27, 1958 Garden Bay 50 Total 1095 Weights were recorded to the nearest gram using a dietary pan balance calibrated by 4-gram intervals. All fish with the exception of the Kates Bay sample of Janu- ary, 1957, and those spawning-run samples taken throughout May, 1958, were used in the study of the length-weight relationship. 11 The sex was noted on those fish taken during July, 1958, and sex differences compiled from these data. Age Determinations Scales were taken from the left side of the body be- low the lateral line and directly behind the posterior end of the pectoral fin. The position of "key" scales taken for purposes of determining the body-scale relationship is described in detail under a subsequent heading. The scales were impressed on cellulose acetate, 0.020 inches in thickness, by a roller press constructed after that described by Smith (1954). These impressions were examined and measured using a Bausch and Lomb Tri-Simplex MicrOprojector under a magnification of 45 times. The length of each "key" scale was measured from the focus to the anterior edge along the interradial Space most nearly collinear with the anterior-posterior axis. The distance from the focus to each annulus was measured along the greatest radius of the scale. All measurements were made to the nearest millimeter and recorded on calibrated IBM cards. The age of each fish is given in terms of completed years of life and was determined by counting the number of annuli on the scale. (All young-of-the-year fish were assigned to age-group 0.) Joeris (1956) found that the 12 number of annuli on the scales of the yellow perch of Green Bay, Lake Michigan, is a dependable criterion for age determination. Because of the variation as to time of annulus forma- tion among the perch of northern Lake Michigan, all fish taken during the month of May were credited with an annu- lus at the edge of the scale regardless of whether one was present. BODYFSCALE RELATIONSHIP Before calculating past growth, a study was made of the relationship between body and scale growth. This re- lationship had already been described for the yellow perch of Green Bay by Joeris (1956) but, in accordance with his proposal, it was believed necessary to determine the re- lationship for the stock under study. Other studies of the body-scale relationship in yel- low perch have been reported for Saginaw Bay (Hile and Jobes, 1941), Lake Erie (Jobes, 1952) and Lake of the Woods (Carlander, 1950). Carlander described the rela- tionship in Lake of the Woods by two second-degree parab- olas, one fitted to data from fish 50-150 millimeters in length, the other to fish from 19-256 millimeters, inclu— sive. JObes (1952) found that the body-scale ratio for scales taken below the lateral line in the perch of Lake Erie was constant for those fish over 4.6 inches. This ratio was best described by a straight line which passed through the origin. The body-scale ratio of fish from 2.5 to 4.6 inches was not constant due to the more rapid increase of the scale diameter. This increase in relative size follows approximately a straight line but its slope is less than that of the line fitted to the data for the - 15 - 14 larger fish. Due to the discontinuity of the body-scale. relationships, all direct-proportion computations of length less than 4.6 inches were corrected. Because of the con- sistency in the average ratios no corrections were made for lengths of 4.6 inches or more. Hile and Jobes (1941) and Joeris (1956) found these same relationships held approxi- mately true for the perch of Saginaw Bay and Green Bay, respectively. In order to best describe the body-scale relationship for the stock under study, key scales were taken from 104 yellow perch having a size range from 50 to 510 millimeters. This key scale came from the third row below the lateral line directly beneath the sixth spine of the dorsal fin; it is the same key scale that was used by Hile and Jobes (1941), Jobes (1952), and Joeris (1956). These fish were selected for size distribution and were taken from the four major sample areas: Kates Bay (12 fish), Garden Bay (24 fish), Garden Bluff (58 fish), and Gray's Springs (20 fish). The regression of body length on scale radius was deter- mined for each area separately by the method of least squares. According to Whitney and Carlander (1956) this regression is the proper one to use in describing the relationship between body and scale for growth computa- tions. 15 The following equations were determined: Kates Bay Y a 41.75 + 1.1656 X Garden Bay Y a 71.85 + 0.8592 X Garden Bluff Y a 26.51 + 1.5227 X Gray's Springs Y a 80.78 + 0.7452 X An analysis of covariance was then computed as de- . scribed by Snedecor (1956) to see if a common line might be used to best describe the relationship in all sample areas. The results of this analysis are shown in Table 2. These lines have both significantly different lepes and intercepts. From Figure 2 it can be seen that the two most widely divergent regression lines are those representing Gray's Springs and Garden Bluff. It was also noted that the mean length of fish from the Garden Bluff sample was 201.9 mm. which far surpassed the mean length of the Gray's Springs sample, 165.6 mm. Jobes (1952) pointed out that neither the stage of maturity nor the sex should influ- ence the body-scale ratio, and that length of the fish was the only factor to have an effect on this ratio. To compare the body-scale relationships between these two areas, those fish with a total length of 200 milli- meters or greater (10) were excluded from the Garden Bluff sample to reduce this sample mean length to approximate l6 .meh ma Hesmqm ens .oaqawm no npwnea sees a . I H.@ H I mmawwwma smeamssm snow esp go mpmeonepqfi on» smesnep mononemmwd s when» mH .m .moh ma Hmsmnd ens mmfi .. Elm o.¢NmH «mpqowowmmooo qowmmoamon mamssm snow map nomspen mosenouuwd e omen» mH .H mémmém mm mmmaé 4.833 35.3 «.mmis mm Hence m Res; Tommi m mass: .34 m 33 TREE mm SSA Toomrsfi Tmmfimm TREK om 858 a. 0.1mm; EASE m Hooo .mom 0 {m3 SST? em n33; m a.smav mew meow 3 £34 mémfima TESS «336 2 am moses s mam mats; ma mmié Resort Trend Tammie 3 mwfinmmwwwno m as? immm£ mm mommé SST: oémim @323 mm Rmfimwwg m 0.8m odomfi em smmmé @8me SETS 0.3%? R 83m mmmwee a emmwwm m8 H .Heoo .wom mh SH NM H mend magaem snag .meend magnum Howws Bonn nonom soaaow Ho AHAmGOprHem oawomlmuom no N ednma mflmhawqd eoqwfinsboo Figure II. Linear regression of body-scale relation- ships as determined for the four sample areas. - 17 _ 30°F / 260- / / / / L / / / 220 , RATES BAY ‘2‘ GARDEN awn 5. ISO - GARDEN BAY E5 GRAY'B eenmee (9 z u: -' I40- 5 / / 8 / / /// / IOO" /// // / / // // // / /// 6° /// / / / / 20 o .40 so |20 |60 zoo SCALE RADIUS (mixes) -13.. 19 that of the Gray's Springs sample. The regression lines were again compared by an analysis of covariance and were found not significantly different at the 5% level (See Table 5). It was then assumed that the differences in regression lines were not due to differences in the body- scale relationship in the different sample areas, but rather to the size range of the individuals making up the sample. It may also be true that in the larger fish, the ratio of scale radius to body length is not constant and a curvilinear relationship does indeed exist, as was found for smaller fish by Carlander (1950). To check this as- sumption, a curvilinear regression.was determined using all the data from the combined sample areas (See Figure 5). The data gave the following equation: I = 10.48 + 1.5636 x - 0.001265 1:2 This regression was compared to the common linear regres- sion by an analysis of covariance (See Table 4) which showed the two lines did not differ at the 5% level of significance. The curvilinear relationship as shown in Figure 5 gives the impression that at larger body lengths, body growth is proportionately greater than scale growth. .oaqawm Ho summed new: . no .oondonquflm no Ho>oH Rm on» no on ma Hogans one mo.N n m” H a m 9. wmmaqawm esp onp no mpmoonopna on» somepon mononmmmwv w when» mH .N I C u 0“” ” oodmoamwnwwm mo Hoboa &m can we on ma Hoewnw one mm H Mdmmm m wmpqoflcwmmooo nowmmonwon madame can on» noospop oonoammmfld a when» mH .H m.mm H.mm¢.m mm 0.0mm.¢H o.mmm.MH o.omH.oH 0: Hence a o.auH o.umH H . mamas .nea e m.mm m.mHm.m mm m.mm¢.¢H m.oH¢.MH m.omH.eH mm noaaoo m m.H¢H m.H¢H H .umoo .Mmm a m.mw a.muH.m um anpHa m m.am m.mma.H mH mmsa.o m.mme.m m.mmm.o m.¢mm.m mH mqunmm.mwmwne m .Am.wmav m.su a.OH¢.H mH comm.o u.¢ma.n o.mmm.o o.mmm.a om «asHm queues H onwzdm u H .Hooo .wom h bx N H send oagawm mafia nama N N N . .Aoagamm Human seesaw on» Bonn dodfiaoxo .aa CON Hm>o nmflm Hadv musam nephew and mmnwnmm m.hdaw eon“ nonom Boaamw Ho mflnmnowpmaom oawomlhvom no mwmhaqu oonwwnw>oo m canoe Figure III. The linear and curvilinear relationships of body length to scale radius determined using the combined data for all sample areas 0 - 21 _ BODY LENGTH 280 ,. a Y 3 25.95+|.269 X—l , 240 N O 0 ISO I20 80 4O i l a l . 0 3O 90 ISO 2|O SCALE RADIUS (ma. x 43) ' - 22 - 23 .oonmoflmwdwwm Ho Hoboa &m can pm on ma Hosmqw one mmm.m u WWW u m «gowmmvhwmh .Hdfiflfiflflzfio Cg HMOHHHH DAD. fivmgpmp OOHOHOHHHU .m 0903p mH oH 0.005 mom H oononommwn o.owH mmH.nH mm QOHmmmnmmm nsoaHHHpnso H.HmH mmm.uH oOH nOHmmonmom umquH unadwm use: Nn sodomnm no mmoHMoq doapdahdb Ho oonfiom mafinmqoapmaom oflwomlhoom Ho mqowmmonmom nwoqfiafl>nso was Homqfiq domapmm ooqwflnm>oo mo mwthmQ< é ednwa 24 Since this relationship did not seem biologically feasible it was then decided to run a curvilinear relationship on the data from Garden Bluff (55 specimens) to see if a given area followed the trend of growth portrayed by the general curve. The relationship from Garden Bluff showed a consistent increase in scale growth with increasing body lengths. It was then assumed that discrepancies in the data and perhaps inadequate representation of the larger individuals in the samples, were responsible for depicting the larger fish as having preportionately greater scale growth; and that this is not a biologically feasible rela- tionship. Since the overall curvilinear relationship and the common linear regression did not differ significantly, it was decided that the common linear regression, Y = 25.95 + 1.269 X, although not in agreement with the results obtained by Joeris for the Green Bay stock, would best fit the data, would be easier to handle in subsequent calculations, and would give the most reliable results in determining pre- vious growth. The intercept was taken to be 26 millimeters. This value is very near the length of the fish at which Pycha and Smith (1955) were first able to detect scales on Red 25 Lakes perch in the body region from which the key scales were taken. This intercept also agrees well with personal observations on scale formation of young-of-the-year perch (25 to 50 mm.) taken from Garden Bay on the 15th of July, 1958. The scales of these fish were imbricated along the mid-lateral body walls. Calculated lengths were then computed using the formula: 8 (Lt - 2§l Ln 26 + St Sn where Ln equals calculated length at end of "n" years, Lt equals total length at capture, Sn equals radius to the "nth" annulus, and St equals total scale radius. This method of calculating previous growth was de- vised by Fraser (1917) and is based on the assumption that body growth is related to the proportional growth of the scale and not to the absolute size of the scale. Whitney and Carlander (1956) found that this method, al- though not entirely satisfactory, gives results which are fairly accurate. LENGTH-WEIGHT RELATIONSHIP The length-weight relationship of fish having con- stant form and specific gravity can best be described by the equation, W a 0L3, where W equals weight, C equals a constant, and L equals length. This relationship is rarely encountered, however, due to the variation in weight and form of the different fish species. A more general equation, W a an, where "c" and "n" are deter- mined empirically, has been found by Hile and Jobes (1942) and Jobes (1952) to adequately describe the length-weight relationship for yellow perch. In the study of the general length-weight relation- ship of the Big Bay de Noc perch, 592 specimens from 5 separate areas were used to calculate, by the method of least squares, the following linear equation: Log N a -5.5561 + 5.257 Log L where W a weight in grams and L a total length in milli- meters. This equation may also be written as: w . 3.457 x 10'5L5°257. The 592 fish chosen were not selected for size or sex, but all samples taken during the spawning-run period of May, 1958, were omitted due to the possible bias result- ing from varying stages of maturity of the gonads, and the -26- 2? differences in gonadal weights between males and females. The graphical representation of the length-weight relationship as a smooth curve is shown in Figure 4. The curve represents calculated weights while the dots are derived from empirical data. The range of the empirical weights was from 27 to 599 grams. Comparison with the Length-Weight Relatignship of 9213; great Lakes Stocks of Perch The length-weight relationship of the yellow perch in the Great Lakes has previously been reported as follows: Lake Erie - (Jobes, 1952) w . 1.766 x 10"5 L5°015 Saginaw Bay - (El~Zarka, 1958) w = 3.9975 X 10'5 L2'620 Lake Michigan - (Hile and Jobes, 1942) w - 5.8405 x 10'5 L2'81 Green Bay - (Hile and Jobes, 1942) w - 0.9519 x 10"5 12'135 These relationships are all based on standard length, therefore they cannot be directly compared to the relation- Ship found in the Bay de Noc fish since it was derived using total length. Weights were calculated from the dif- ferent length-weight equations of Great Lakes yellow perch Population by El-Zarka (1958). (See Table 5.) The only weight differences noted in a comparison between Big Bay Figure IV. The length-weight relationship of 592 yellow perch from Big Bay de Noc. - 28 _ 420 360 WEIGHT IN GRAMS 300 240 I80 I20 60 w- 3.437x IO" Lu” 1 l 1 60 I20 I80 240 300 BODY LENGTH IN MM. .. 29 .. _ Table 5 Length-Weight Relationship of Yellow Perch Pepulations in Different Great Lakes Waters’ 3O (Data from: Hile and Jobes, 1942; Jobes, 1952; El-Zarka, 1958) Total Length Green Calggllgted £38192; 1351;111:235 Lake Inches Millimeters Bay Michigan de Noc Bay Erie 5.0 127 0.7 1.0 0.7 0.8 0.8 5.5 140 1.0 1.4 1.0 1.0 1.1 6.0 152 1.4 1.8 1.5 1.4 1.4 6.5 . 165 1.7 2.2 1.7 1.8 1.9 7.0 178 2.2 2.7 2.2 2.5 2.5 7.5 191 2.8 5.4 2.8 2.9 2.9 8.0 205 5.4 4.0 5.4 5.5 5.5 8.5 216 4.1 4.8 4.2 4.5 4.1 9.0 229 4.9 5.6 5.0 5.2 5.0 9.5 241 5.8 6.6 5.9 6.2 6.1 10.0 254 7.0 7.7 7.1 7.5 7.0 10.5 267 8.1 8.9 8.5 8.6 8.5 11.0 279 9.4 10.1 9.6 10.0 9.4 11.5 292 10.8 11.4 11.1 11.5 10.9 12.0 505 12.2 12.8 12.8 15.2 12.5 12.5 518 15.9 14.4 14.7 15.1 14.1 13.0 550 15.8 16.0 16.6 17.2 15.8 \ Taken in part from El-Zarka (1958). 51 de Noc fish and those from Green Bay were in the larger lengths. The overall rate of weight increase up to a total length of ten inches in the Bay de N00 perch was less than that found in other waters with the exception of Green Bay. Fish between eleven and thirteen inches total length grew at a pr0p0rtionately greater rate in Bay de Noc than did the fish from any of the other areas, and at a total length of thirteen inches only the Saginaw Bay stock out- weighed them. AGE AND GROWTH Growth_ig Length of thg_§ge-Groups In presenting the data for the calculated growth his- tories of the yellow perch in Big Bay de Noc, growth in the different sample areas was determined separately to see whether any significant differences in the growth rate prevailed between the sample areas, thereby giving indi- cations of the possible occurrence of isolated sub-. p0pulations. Also, the sexes were kept separate in as much as differential growth was found between male and female perch by Hile and Jobes (1941, 1942) and by Jobes (1952), and was assumed to be present in the perch of Big Bay de Noc. Data for the calculated growth of age-groups I to VIII (See Table 6) are derived from all samples taken throughout the course of the study to give the most accurate estimate of actual growth conditions. Comparisons of the calculated lengths for all age- groups showed a tendency for calculated length at a given age to be consistantly larger in the older age-groups. In other words, there was a progressive decrease in the calcu- lated lengths at the end of any given year of life from fish of age-group VIII to age-group I. These discrepancies are the Opposite of those described by Lee (1920). Lee's - 52 - 33 Table 6 Calculated Total Length at the End of the Different Years of Life for Yellow Perch (Sexes Combined) from Big Bay de Noc, Lake Michigan N0. of Age WE‘Length (Millimetepgl at End ofiIear Group Fish 2 5 4 5 6 7 8 I 2 66 .0. O O .0. O O O O 00. 0. II 7 62 102 ... ... ... . . ... . (40)" III 670 70 109 152 .. . . .. ... . (39) (45) IV 168 69 115 157 195 .. ... . .. (46) (52) (36) V 149 72 116 164 199 228 .. .. .. (44) (48) (55) (29) VI 55 72 117 s 162 198 225 251 ... ... (45) (45) (56) (27) (26) VII 5 74 122 169 202 227 255 279 ... <48) (47> (55) (25> <26) (26) ‘VIII 2 79 121- 157 201 254 258 280 505 (42) (56) (44) (55) (24) (22) (23) Grand average calculated llength 70 111 155 196 227 252 279 505 Grand average .increment of length 70 41 44 56 29 26 24 25 .Accumulation of average increments 70 111 155 191 220 246 270 295 I Increments in parentheses. 54 "Phenomenon of apparent decrease in growth rate" shows wide disagreements occurring in the calculated lengths whereby those of older fish are decidedly less at a given age than for the younger individuals. The possible ex- planations given by Lee for these discrepancies are: greater longevity of the slower growing individuals due to a differential mortality rate; or a constant decrease of scale diameter caused by erosion, reabsorbtion, or com- paction. The reverse of Lee's "Phenomenon," found in the perch of Big Bay de N00, is not thought to be due to the addition of materials to increase the diameter of the scale. Wallin (1957) reports that although reabsorbtion and con— sequent replacement of the scale periphery is a common occurrence in fish whose metabolic rate is upset by a lack of required minerals or who are subjected to a heavy in- cidence of parasitism, the addition of materials to the osseous or fibrous layers of the scale, once calcification has occurred, is not possible. And, since the body-scale relationship of this stock has been determined, the possi- bility of large errors in calculated lengths resulting from the method of computing these lengths is highly unfeasible. A differential mortality rate with the faster growing in- dividuals attaining an older age does not seem to be an explanation , due to the constant removal of these fish by 35 exploitation beginning as soon as they reach the legal size limit of 8% inches. Similar growth discrepancies have been reported for ‘ye110W'perch in Saginaw Bay, Green Bay and northern Lake lMichigan by Hile and Jobes (1941, 1942). These differ- ences were thought to have been due to either the selective action of the standard 2%-inch mesh gill—nets used for sampling, or the segregation of the fish according to size and maturity. It was felt that the method of sampling the Bay de Noe perch (experimental gill-nets) had little influence on these discrepancies due to the fact that fish of all sizes, regardless of growth rate, had equal Opportunity to be taken in the varying mesh sizes of the nets. A consideration of the biological changes that took place in Big Bay de N00 and vicinity during the last 16 years might lead to an explanation of the discrepancies in calculated growth between the age-groups. A decline in the lake trout and Whitefish p0pulations due to the action of the predatory sea lamprey should have resulted in the re- placement to the biomass of these fish by other species. Although the yellow perch is not a consistant deep water form, as are both the lake trout and the Whitefish, it is felt that this species should have responded somewhat to 56 such a biological change. This response may have been short-lived due to the appearance of the alewife, Algsg pseudoharengus, which first appeared in Lake Michigan waters in 1949 (Miller, 1957). This species has now bee come firmly established in Lake Michigan where it is found in abundance. It is possible that the alewife has now not only filled the niche left in the biomass by the disappear- ance of the lake trout and Whitefish, but has affected the balance of the remaining species and is a strong competi- tor for food and space. This increased interfspecific competition between the perch and the alewife is a logical explanation for the de- crease in growth rates between the 1950 year class (age- group VIII) and the 1957 year class (age-group I). From the s00pe of this present study, it is not possible to predict how this inter-specific competition will affect the growth and abundance of Big Bay de N00 perch in the future. ‘Qggggal Growth Higtggy The growth curve in Figure 5 is a general curve de— rived to best typify the growth of the Big Bay de Noc perch population as a whole. The curve was determined by combining data for all age~groups (1056 fish) and since the age-groups have heterogeneous growth histories, the Figure V. General growth in length and annual incre- ment in length of Big Bay de N00 yellow perch collected during 1957 and 1958. (Sexes combined). - 37 - 4:2 mmIOZ. Z. IFGZNJ >000 O 8 6 d .1 . 300- ' I50 '- . m 2 250 - .22 z. 15.0sz room I00- 50- AGE (Yeane) -58- 59 resulting curve is one which may better be applied to the population rather than a typical individual. Two expres- sions of growth are given on the bottom of Table 6. The first, the grand average calculated length, is an indica- tion of the growth rate occurring in an exploited stock, while the second, the accumulation of the average incre— ments, serves to show the slower growth potential of the stock if it were not subjected to exploitation (El-Zarka, 1958). It was felt that the grand average calculated length would be more closely correlated with actual growth patterns and would clearly illustrate the growth as it oc- curs in this exploited p0pu1ation. 2l§2r0p0rt102§te Growth of Sexes Calculated growth histories for female and male yel- low perch are shown in Tables 7 and 8, respectively. The length of both sexes was similar for the first year of life. The growth curves of the sexes started to diverge after the first year, the females being longer (See Fig— ure 6). The females maintained this constant advantage (about 5 mm.) for all age-groups older than age-group II. This difference in growth between the sexes did not affect the age at which legal size (8% inches) was attained. Both sexes required an average of five years growth to reach legal commercial size. (The average age of fish in the Table 7 4o Calculated Total Lengths at the End of the Different Years Collected During July, 1958 of Life for Female Yellow Perch from Big Bay de Noc Age No. of Length (Millimeters) at End of Year Group Fish 2 5 4 5 7 8' I 2 66 ... ... ... ... ... ... ... II 6 62 100 ... ... ... ... ... . . (38)‘ III 247 72 108 145 ... ... . . ... ... (36) (37) IV 59 68 115 152 185 ... ... ... ... (47) (57) (53) V 17 71 115 161 192 222 ... ... ... (42) (48) (51) (50) VI 4 64 107 149 185 218 246 ... ... (43) (42) (56) (33) (28) VII 1 71 118 160 205 229 259 294 ... (47) (42) (45) (24) (50) (35) VIII 1 78 127 169 215 258 260 284 508 (49) (42) (46) (25) (22) (24) (24) Grand average calculated length 71 109 147 188 222 251 289 508 Grand average increment of length 71 58 58 55 5O 27 50 24 Accumulation of average increments 71 109 147 180 210 257 267 .291 ' Increments in parentheses. 41 Table 8 Calculated Total Length at the End of the Different Years of Life for Male Yellow Perch from Big Bay de Noc Collected During July, 1958 “ f —7 - Age Number of Leggth (millimeters) at End of Year 1 2 5 4 5 Group Fish II 1 64 113 .00 000 000 (49)* III 105 72 105 158 ... ... (53) (53) IV 25 67 107 152 184 ... (40) (45) (52) “""7v 4 69 106 ‘ 152 189 215 (57) (46) (57) (26) " Grand average calculated length 71 105 141 185 215 Grand average increment of length 71 55 56 55 26 Accumulation of average increments 71 106 142 175 201 1 Increments in parentheses. three commercial samples taken in May, 1958, from Nahma Flats and Garden Bluff was 5.04 years.) This differential growth pattern has been noted in the four stocks of yellow perch previously studied in the Great Lakes. The differences in length were not as pronounced Figure VI. General growth in length and annual increments in length of Big Bay de Noc perch collected during July, 1958. (Male, broken line; female, solid line). -42- mmzoz. 2. 15.0sz >000 m 8 6 u - - 300F- 250 - I50 - _ m 2 .22 2. 15.02”; >000 I00- 50- AGE (vane) -43.. 44 in the present study as were found in southern Green Bay by Hile in 1942. Older males (over age-group V) were lacking in this study and had these fish been adequately represented, a greater length discrepancy might occur be- tween sexes in these older age-groups. Despite the differences in growth, the same general description of the course of growth may be applied to both males and females. The most rapid growth takes place in the first year of life, after Which annual increments de- creased continuously as is shown in Figure 6. Growth Histories in Individual Sample Areas As was previously mentioned, the growth histories of fish from the sample areas were determined separately to see if any single area differed from the others with re- spect to rate of growth, thereby giving possible indica- tion of the existance of sub-populations. The tabular results of the calculated lengths for males and females for each year of life from the different sample areas are given in Appendix A. Analyses of variance were performed between the sample areas and the calculated lengths of each age-group at given years of life with the sexes held constant. The only sig- nificant differences at the 5% level resulted between the areas and calculated lengths of age-group III males at both 45 the third and second annulus, and between areas and the calculated lengths of age-group III females at both the third and second annulus. Although these discrepancies in growth were noted be- tween the areas,it is felt that they do not give positive evidence of existing sub-populations, but rather indicate a trend toward variation of growth between younger indi- viduals inhabitating the different areas. This trend may finally result in the creation of isolated sub-p0pu1ations through inter-specific competition for food and space be- tween the alewife and the yellow perch. Comparisons of Growth With That ipOther Great Lakes Waters Comparisons of growth in length between Big Bay de N00 and other Great Lakes waters (See Table 9) showed that fish from Lake Erie had a decidedly faster rate of growth throughout their life. Saginaw Bay and northern Lake Michigan.fish both had comparable rates of growth, with those perch from Lake Michigan growing at a slightly more accelerated pace. The males of southern Green Bay and Big Bay de N00 also showed similar rates of growth. The Bay de Noc females grew at approximately the same rate as the males, while in Green Bay the dispr0portionate growth of the sexes was more pronounced in the later years of life. 46 Table 9 Growth in Length of Yellow Perch from Different Localities of the Great Lakes (Sources of data: Lake Erie, Jobes (1952); Saginaw Bay, El-Zarka (1958); southern Green Bay and northern Lake Michigan, Hile and Jobes (1942); Big Bay de Noc, 1958 sam- ples, present study) Ave. Calculated Length (In.) at and Mar Locality and Sex I 2 5 4 '5' 6 7 ‘Lake Erie M818 . 506 606 8.4 9.4 1001 0000 0000 Female 1 307 607 806 908 1007 0000 0000 Sexes combined 5.6 6.6 8.5 9.6 10.4 .... .... Saginaw Bay Male 2.6 4.2 5.6 6.7 7.6 8.5 9.5 Female 1 2.7 4.5 5.9 7.5 8.8 10.2 11.5 Sexes combined 2.6 4.2 5.8 7.1 8.2 9.4 10.2 Southern Green Bay Male 2.9 4.6 6.0 7.4 8.4 9.6 10. Female 2.8 4.6 6.4 8.0 9.0 10.4 11.5 Sexes combined 2.8 4.6 6.2 7.7 8.7 10.0 10. Northern 6 Michigan & 2 2.8 4.4 5.9 7.1 8.5 9.6 .... Big Bay de Noc Male 208 4'02 06 705 805 0000 00.0 Female 3 2.8 4.4 5.8 7.4 8.7 .... .... Sexes combined 2.8 4.5 5.7 7.4 8. .... .... 1Unweighted means. 2No data for sexes separately. 5Weighted means. 47 Table 10 gives a comparison of the growth in weight at time of annulus formation between Great Lakes waters. As suspected, the faster growing Lake Erie stock was con- siderably heavier and maintained its consistent weight advantage over all other stocks. The Green Bay perch were heavier than those from Bay de N00 in the earlier years of life with the females maintaining their heavier status throughout. During the fifth year of life the Bay de Noc males surpassed those from Green Bay in weight. 48 Table 10 Growth in Weight of Yellow Perch from Different Localities of the Great Lakes (Sources of data: Lake Erie, Jobes (1952); Saginaw Bay, El-Zarka (1958); southern Great Bay and northern Lake Michigan, Hile and Jobes (1942); Big Bay de Noc, 1958 sam— ples, present study). t L Average Calculated Weight (Ounces) at End of Year Locality and Sex 71 2 5 4 5 6 7 Lake Erie Male 0.28 1.98 5.98 5.64 7.20 .... ..... Female 10.52 2.08 4.41 6.70 8.68 .... ..... Sexes Combined 0.50 2.05 4.20 6.17 7.94 .... ..... Saginaw Bay Male 0.09 0.45 1.10 1.98 2.98 4.50 . Female 10.10 0.46 1.51 2.86 4.82 7.79 10.27 Sexes Combined 0.10 0.44 1.20 .42 .90 6.04 . Southern Green Bay Male 0.14 0.60 1.58 2.57 4.16 6.28 . 0 Female 0.14 0.60 1.62 5.59 5.08 8.01 10.85 Sexes Canbined10.14 0.60 . 0 2.98 4.62 7.14 . Northern Lakg Michiganl 2 0.21 0.78 1.75 2.95 4.75 7.16 ..... Big Bay de Noc Male 0.11 0.41 1.04 2.52 Female 3 0.11 0.49 1.19 2.61 Sexes Combined 0.11 0.47 1.14 2.58 #f-P UIU'IH OO)\J iUnweighted means. 2No data for sexes separately. 3Weighted means. COEFFICIENT 0F CONDITION The coefficient of condition, "K," is accepted as an index which describes the general "well-being" or "plump- ness" of fish. This index value may be affected by any environmental factor having an influence on condition, such as availability of food. This value is also under the in- fluence of many physiological factors, such as disease or state of sexual maturity, which may weaken or emaciate the individual, thereby camflng a decline in relative heaviness. According to Jobes (1952) individual growth rate does not influence condition values in yellow perch and therefore condition cannot be correlated, as such, with growth. The average coefficient of condition of the perch in Big Bay de Noc was derived by the formula: W x 105 ' Ems-”'55— where KTL is the condition factor based on total length, W is the weight in grams, and L is the total length in millimeters. The KTL value was determined for 155 males and 511 females from five different localities (Garden Bay, Gray's Springs, Puffy Bay, Garden Bluff, and Katee Bay). These data were compared by an analysis of variance, correcting for the unequal number of individuals per sample area and for the _ 49 _ 50 dispr0portion of sexes, as described by Snedecor (1956). The results of this analysis are shown in Table 11. The KTL values between sample areas differed significantly at the 5%11evel, but they did not differ with regard to sex. That is to say, that KTL values of males and females taken from the same locale did not differ, but there were differences between the KTL values of sample areas. This might possibly be explained by the presence of sub-p0pu1a- tions within the general stock, all other factors being equal. A Multiple Range test (See Appendix B for explanation of test) described by Duncan (1955, 1957) was then per- formed on the separate sexes to determine which of the five areas these differences did occur. The ranked means of the males (See Table 12) singled out Kates Bay as hav- ing the lowest KTL value and Garden Bay as having the high- est. The test showed no significant differences at the 5%.level between the means of the Garden Bay, Garden Bluff, Puffy Bay and Gray's Springs samples; and Gray's Springs and Kates Bay did not differ. The ranked means of the KTL values of females exhibited the same order as those of the males with Katee Bay again having the lowest value. The test on the females (See Table 15) gave the following re- sults: the means of Garden Bay, Garden Bluff, Puffy Bay 51 Table 11 Analysis of Variance Between "K8 " Values of Sample Areas and Sex (Interaction negligible with dispr0portionate sub-class numbers). Male Female l 2 Area n1 X1 112 W D WD Gray's Springs 8 1.04 60 1.10 7.059 —O.6 -0.4255 Puffy Bay 15 1.15 51 1.12 10.109 0.1 0.1011 Garden Bluff 57 1.14 110 1.15 57.545 0.1 0.5755 Garden Bay 10 1.16 18 1.15 6.429 0.1 0.0645 91,561 . -1.9979 Preliminary Analysis of Variance of Original Data Source Degrees of Freedom Sum of Squares Mean Square Total 445 8.4781 Sexes 1 0.0585 0.0585 Areas 4 0.9999 0.2499 Individual 456 7.1902 0.0164 Interaction sum of squares: 2WD - (2WD) /ZW :- 051552 Correction for disproportion: 8.8. of sexes - a-Oinfiél 1 Completed Analysis Source Degrees of Freedom Mean Square 83x93 1 0.04569“ Areas 4 0.2465 Interaction 4 0.0558 Individuals 456 0.01649 Tests: 0.04 6 0.246 0 Area 07016£9 ‘ 14'9“" I"(4,400) ' 2'39 Interaction 8'8 8° . 2.04 3(4 #00) a 2.59 . ’ nlnz 2 l - - w. D8X2-X1 52 Table 12 Multiple Range Test to Determine the "KTL" Values of Male Yellow Perch Not Significantly Different Between Sample Areas. a) b) I L Analysis of Variance Source Degrees of Freedom he can S uu Between Areas 4 0. 21%2e Error 150 0.0215 s - 0.1459 Critical Values R'p 0.4041 0.4260 0.4410 0.4510 0) Ranked Area Means and Replication Numbers.’ 0 D E 0'97 W 1‘15. TT'. 4 I716 (45) (8) (15) (57) (10) d) Test Sequence Results" E-A ' a 0.7685 0.4510 E-B ' . 0.5577 0.4410 (BCDE) D"A . ‘ 102050 004410 EC-A ' . 0.7588 0.4260 B-A ' a 0.2579 0.4041 (BA) * Area code: A - Kates Bay B - Gray's Springs 0 - Puffy Bay D - Garden Bluff E - Garden Bay #0 The means within the parentheses are not significantly different at the 5% level. 55 Table 15 Multiple Range Test to Determine the "KTL" values of Female Yellow Perch Net Significantly Different Between Sample Areas a) Analysis of Variance Source Degrees of Freedom Mean Square Between Areas 4 0.09120 Error 506 0.01446 8 = 0.12024 b) Critical Values :zfa-réél- 78* 373% 3-8)- R'P 0. 5550 0. 5511 0.5651 0. 5715 0) Ranked Area Means and Replication Numbers. 0 D E T048 1710 IT 2 1'715 ISIS (92) (60) (51) (110) (18) d) Test Sequence Results“ E—A ' a 5.569 0.5715 E-B ' . 0.2651 0.5651 (BCDE) D-A ' - 0.821 0.5651 C-A ' . 0.4905 0.5511 B-A)’ = 0.44515 0.5550 (A) ’ Area code: A - Katee Bay B - Gray's Springs 0 - Puffy Bay D - Garden Bluff E - Garden Bay " The means within the parentheses are not significantly different at the 5% level. 54 and Gray's Springs samples did not differ at the 5% level of significance as was found in the males. 0n the other hand, the mean value of the Katee Bay sample differed sig- nificantly from all other areas. The four areas not significantly different with re- spect to mean KTL values were within relatively close proximity to one another while Katee Bay was somewhat re- moved. It might therefore be postulated that the fish inhabitating the area between Garden Bluff and Gray's Springs are from one sub-population while those of the Katee Bay area are from another sub-p0pu1ation. Comparisons of the Avepgge Condition Coefficiept Between phe Waters of the Great Lakep In order that comparisons might be made between the condition factor of Big Bay de Noc perch and other data previously reported for the Great Lakes, it was necessary to change the average K—total length value, (KTL)’ to one corresponding to K-standard length, (KSL). This conver- sion was done using the formula: 5 KSL " 1' KTL where KSL is the condition factor based on standard length, KTL is the condition factor based on total length, and r is the ratio of total length to standard length. The ratio of total length to standard length 55 (1.172), was determined by Hile (1942) for the yellow perch of Green Bay varying in standard length from 150 to 209 millimeters. This cubed ratio, multiplied by the average KTL value (1.11), gave a resulting KSL value of 1.79. ‘ In comparison to other values reported from the Great Lakes, the Bay de Noc perch are considerably lighter for a given length. For Lake Erie perch, Jobes (1952) reports an average KSL value of 1.91, while Hile and Jobes (1941) found a KSL value of 1.8 for Saginaw Bay and Hile and Jobes (1942) reported values of 1.87 and 2.18 for Green Bay and northern Lake Michigan, respectively. FOOD HABITS . The stomachs of 247 yellow perch were taken from five sample areas for subsequent food analysis. Table 14 gives the major groups of organisms consumed and the percentages of stomachs containing these food items. The percentages expressed are based only on the number of stomachs con— taining food and not the total number examined because it has frequently been demonstrated that fish may regurgitate their stomach contents after becoming entangled in the meshes of a gill-net. Mayflies (Hexagenia and Ephemera), crayfish (Cambarus), isOpods (Asellus), amphipods (Gammarus and Hylalla), and midge larvae (Tendipedidae) were the organisms represented most frequently in the stomachs of perch found in Big Bay de Noc. In the deeper waters of the Garden Bluff area a few larger perch were found to have fish remains in their stomachs. This was the only indication of fish predation encountered. The species of these fish could not be de- termined due to advanced state of digestion. Coots (1956) reported small crustaceans, snails, and fish as the primary food of the yellow perch in the Klamath River, California. Ostracods, copepods, and midge larvae are the major food items of young perch, according to - 56 _ 57 wmmH .mH ane m 4H .. 4H no He so mm .. mm mom noose mmmH .mH eHse uH H .. 04 HH mH um om an o nquuam n.58nu mmmH .HH eHse m 5H .. e am no om an MH mm mom unease mmmH .oH eHse .. m RH MH Hm MH 4 s m 84 eeon noonoo wmmH .m eHne .. .. .. m mm mm om cs m om mom emunm owonpo mHeonm anm oomeHa noHHH noAHe neon ane neon soon ana open one 1582 Imauvmo lagged Ihono IomH mnowaopm some oagamm «6 .oz .chom one; maopH muowns> moans ma nomaopm Ho ommpqoonom mm commonmwfl .nonom eoaaom uem Ho mnooaopm n8 esopH 000m Ho nowpenfiepmdn homosuonm #H manta 58 Turner (1920) and Langford and Martin (1941). Moffett and Hunt (1945) found that winter predation by large yellow perch on bluegills was prevalent. PARASITES A sample of 50 yellow perch ranging in size from 205 to 241 millimeters was taken by gill-nets from Garden Bay on November 27, 1958. The fish were immediately examined for external parasites. This examination covered the head, eyes, fins, body, gills, and 0percula. No macro- sc0pic parasites were noted. The gills and vicera were then removed and placed in polyethylene bags. This material was kept under refriger- ation from five to seven days at a temperature of approxi- mately 58° F. after which a complete examination was made. This examination consisted of washing the gills and vicera with isotonic saline and then Opening and inspecting the entire alimentary tract. All organs were checked for cysts or free parasites. The parasites found were trans- ferred to tap water where they remained for 20 minutes. They were then killed by immersion in a mixture of hot alcohol-formalin—glacial acetic acid. No parasitic forms were found in 11 of the 50 fish examined. The trematodes and acanthocephalans were stained in Semicon's carmine and mounted in a commercial medium, Permount. The nematodes were placed in vials containing a mixture of three parts 70% ethyl alcohol and one part - 59 - 6O glycerin, and the vials left unst0ppered. More glycerin was added as the alcohol evaporated. After five days in highly concentrated glycerin, the specimens were mounted in a glycerin-gel medium. Identifications were made using the keys and descrip- tions in Van Cleave (1952), Meyer (1954), and Hopkins (1954). Only four species of parasites were found in the 50 perch comprising the sample. These species were: TREMATODA Order Digenea Family Allocreadiidae Bunodera lucioperidae (Mueller, 1776) This small trematode was found in the stomach and intes- tine of 58% of the fish examined with an average incidence of 5.1 specimens per host. Van Cleave (1954) reported only a single specimen of B. lucioperidae taken from the yellow perch in Oneida Lake, while Pearse (1924) and Fischthal (1945) recorded the species as abundant in the perch of Wisconsin. Van Cleave noted this genus not only to be of high intensity in perch p0pu1ations inhabiting shallow water, but also as having seasonal limitations. No forms were recorded during the summer months of June and July. Dur- ing the colder months Bunodera was found in abundance. 61 ACANTHOCEPHALA Order Palaeacanthocephala Family Echinorhynchidae Echinorpypchus salmonis Mueller 3. salmonis occurred in 52% of the samples and was found exclusively in the lower intestine. The average number of individuals per host was 2.7. This genus was not reported in fish from Oneida Lake by Van Cleave, in Wisconsin by Fischthal, or in Maine by Meyer (1954). Bangham (1955) found p. salmonis in 25 species of fish in Lake Huron; approximately 5% of the perch examined were infested. NEMATODA Order Camallanoidea Family Cucullanidae Dichelype cotlephora (Ward and Magath, 1916) The adult form of Q. cotylophora occurred throughout the intestine while immature worms were found quite frequently encysted in the liver. A single adult specimen was located in the cystic duct. Twenty-four percent of the sample harbored this parasite with an average of 1.7 individuals per host. Van Cleave reported yellow perch were the chief host of 2. cotylophora in Oneida Lake, with an incidence of 62 infestation running 60% and the occurrence of 10 to 15 worms per host. This form has no seasonal variation and is found in hosts from all depths. Bangham noted incidence of infestation to be 50%11n the perch of Lake Huron. The species is also abundant both in Maine and Wisconsin. NEMATODA Order Spiruroidea Family Spiruridae Spinitectus gracilis (Ward and Magath, 1917) A single larval form of the genus Spinitectungas collected from the stomach mucosa. This individual was tentatively identified as S, gpgpilia, The genus is correlated with mud bottom and its 00- currence is independent of depth according to Van Cleave who reported only larval forms infesting the yellow perch of Oneida Lake, while Bangham found mature individuals in the perch of Lake Huron. RELATIVE ABUNDANCE During the years 1944-1949, the fishing intensity for yellow perch was relatively stable in the State of Michigan waters of Green Bay as shown in Table 15. (The percentages given in this table are expressed as percentages of the 1929-1945 mean for both fishing intensity and abundance.) The average fishing intensity for this period of six years was 55.7 percent. With the decline in abundance of the lake trout and the Whitefish in 1949 and 1950, commer- cial fishermen turned to the less economically desirable yellow perch as a "buffer" species in h0pes it would sus- tain them until the two more profitable species reached their former levels of abundance. Between 1950 and 1957 the average intensity for perch increased to 62.6 percent. Relative abundance during this period showed a constant rise to a record high in 1957. Coupled with this sharp increase in abundance was the upward trend of production which, along with intensity, reached a peak in 1955 and after a slight decrease, held stable in 1956 and 1957. The sharp increase in abundance of perch was first noticed in 1955. Going on the assumption that an average of 5 years of growth is required for a fish to reach com- mercial size, it would mean that the 1948 year class, and - 65 _ Table 15 Production in Thousands of Pounds, Abundance and Fishing Intensity (Expressed as Percentages of the 1929-1945 Mean) of Yellow Perch in the State of Michigan Waters of Green Bay, 1945-1957.‘ Year Production Abundance Intensity 1945 125 67 52.6 1944 49 65 22.1 1945 151 150 28.4 1946 116 112 29.5 1947 70 64 51.1 1948 66 55 55.1 1949 65 49 57.6 1950 107 52 58.4 1951 66 46 41.0 1952 175 79 62.5 1955 251 121 58.5 1954 545 158 70-7 1955 411 141 82.5 1956 522 . 128 71.1 1957 550 165 56.4 ‘ Data received from Hile, personal communication, 1959. 65 those immediately subsequent to it, were strong year classes. The strength of these year classes coincided well with the sharp decrease in abundance of the lake trout in particular. It is also interesting to note that in 1948 and 1949 the walleyed-pike reached a peak of abundance and this seemingly had no noticeable effect on the resulting abundance of these same years classes of yellow perch (Hile pp gl., 1955). At present, the abundance of yellow perch is at an all time high. Whether this peak of abundance can stabi- lize or be maintained depends largely on the inter-specific competition afforded the perch by remaining species in the biomass such as the walleyed-pike and the alewife which utilize the same habitat as does the perch. It is felt that the sudden "explosive" appearance of the alewife may, through direct and indirect competition, be a decisive factor in bringing about a decline in the overall abundance of the yellow perch in future times. The explanation of the consistent decline in.gr0wth rates of the 1955 and 1956 year classes of yellow porch in Big Bay de Noc may be found in this factor of inter-specific competition, and also may preview future occurrences. SUMMARY 1. The yellow perch, Egppg,flaveecens (Mitchill), is an important food and sport fish due to its wide distribu- tion and abundant numbers. 2. In the Green Bay area of Lake Michigan the commer- cial production of yellow perch has, during the past 58 years, averaged well over 150 thousand pounds per year. Big Bay de Noc produces between 10 and 50 percent of this annual total. 5. This present study was based on 1095 specimens, 1045 of which were used in the calculation of growth his- tories. 4. The body-scale relationship for the yellow perch of Big Bay de Noc was determined by a linear regression of body length on scale radius for 104 perch ranging in size from 50-510 millimeters. The computed equation was: Y . 25.95 + 1.269 X 5. The relation between total length in millimeters and weight in grams of 592 Bay de Noc perch taken in July, 1958, was described by the equation: I w . 5.457 x 10"5 L5'257 6. The calculated lengths at a given age were con- sistently larger in the older fish. The discrepancies - 66 - 67 noted were exactly the opposite of those described by Lee. 7. The cause of these discrepancies in the Big Bay de Noc perch is attributed to differential growth rates be- tween the varying year classes due to inter-specific com- petition. 8. The length of the sexes was similar in the first year of life after which the females maintained a consist- ent 5-6 millimeter length advantage within each age—group. 9. The annual increments of growth in length decreased with age after the first year in both sexes. Both males and females reached the legal commercial size of 8% inches after 5 years of growth. 10. The compared calculated growth histories of the different sample areas gave no indication of the presence of faster or slower growing sub-populations. Although differences in growth were found in the younger age-groups, they were attributed to the natural variation of growth between the sample areas. 11. The growth in length of Big Bay de Noc perch is comparable to that found in southern Green Bay and is slightly higher than reported for northern Lake Michigan. 12. The growth in weight of the Big Bay de Noc perch ‘Was slower in the younger fish when compared to other 68 Great Lakes stocks but had a more rapid proportional in— crease than any other stock after the third year of life. 15. The coefficient of condition was determined for 155 male and 511 female perch from five sample areas. The average coefficient of condition based on standard length of the Bay de Noc perch was 1.79, which was less than that reported for the other Great Lakes stocks. 14. There were no significant differences found be— tween the coefficient of condition of males and females. The condition index was'not found to be correlated with size or age, but significant differences were found to occur between the Katee Bay area and all other sample areas. 15. Mayflies, crayfish, aquatic isopods, amphipods, and midge larvae were the food items most frequently rep- resented in the stomachs of yellow perch. Very little fish predation was exhibited by the perch of Big Bay de N00 at the time of sampling.‘ 16. Only four species of internal parasites were found ‘to infest the local perch p0pu1ation. None of these spe- <3ies was represented in great abundance and no external IParasites were noted on any of the fish specimens. 17. The relative abundance of the yellow perch in (Ereen Bay is now at an all time high. Whether the 69 population of perch now occurring is able to stabilize at its present level depends largely on the competition af— forded it by the other species inhabiting the same ecologi- cal niche. APPENDIX -70- APPENDIX A Calculated Total Length at the End of the Different Years of Life for Yellow Perch (Sexes Combined) from Katee Bay Collected on January 27, 1958 Age Number of Lepgth $millimeters)at Endlof Year Group Fish 1, 2 5 4 5 6 III 518 68 112 162 ... ... ... (45)* (50) IV 72 68 115 155 191 ... ... (45) (42) (40) V 10 70 110 150 188 224 ... (40) (40) (58) (56) VI 2 74 115 165 195 251 269 (41) (50) (50) (56) (58) Grand average calculated length 68 112 160 191 225 269 Increment of average 68 44 48 51 54 44 Grand average incre- ment of length 68 45 48 40 56 58 Accumulation of average increments 68 115 161 201 257 275 ‘ Increments in parentheses. - 71 72 Calculated Total Length at the End of the Different Years of Life for Yellow Perch (Sexes Combined) from Nahma Flats Collected on May 25, 1958 Age Number of Length (millimeters) at End of Year Group Fish 5 IV 9 76 126 175 219 ... ... ... (SO)‘ (49) (44) V 50 74 125 170 205 255 ... ... (51) (45) (55) (28) VI 8 74 119 160 198 225 251 ... (45) (41) (58) (27) (26) VII 1 74 128 165 190 219 248 271 (54) (57) (25) (29) (29) (25) Grand average calculated length 74 124 169' 206 251 251 271 Increment of average 74 5O 45 57 25 2O 20 Grand average increment of length 74 50 45 57 28 26 25 Accumulation of average increments 74 124 169 206 254 260 285 * Increments in parentheses. 75 Calculated Total Length at the End of the Different Years of Life for Yellow Perch (Sexes Combined) from Garden Bluff Collected on May 23 and May 24, 1958 Age No. of Le th millimeters at End of Year Group Fish 1 2 3 4 5 7 8 IV 23 73 126 172 209 ... ... ... ... (55)‘ (46) (37) V 88 72 115 165 200 228 ... ... ... (43) (50) (35) (28)' VI 21 72 119 165 200 226 250 ... ... (47) (46) (35) (26) (24) VII 1 77 120 183 211 234 253 273 ... (45) (63) (28) (25) (19) (20) VIII 1 79 114 144 188 229 257 276 297 (35) (50) (44) (41) (28) (19) (21) Grand average calculated length 72 118 166 202 228 250 274 297 Increment of average 72 46 48 36 26 22 24 23 Grand average increment of length 72 45 49 35 28 24 20 21 Accumulation of average increments 72 117 166 201 229 253 273 294 *:Increments in parentheses. 74 Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Puffy Bay Collected on July 9, 1958 (Females) Age Number of Length (millimeters) at End of Year Group Fish 1 2 3 4 5 III 23 71 106 144 ... ... (55)* (38) IV 7 69 109 145 180 ... (40) (54) (57) V l 71 113 166 194 229 (42) (55) (28) (55) Grand average calculated length 71 107 144 181 229 Increment of average 71 36 37 37 48 Grand average incre- ment of length 71 51 38 36 35 Accumulation of average increments 71 122 160 196 231 (Males) Age Number of Length (millimeters) at End of Year Group Fish 1 2 3 4 II 1 64 113 ... ... (49) III 10 72 105 136 ... (33) (31) IV 4 66 113 155 186 (47) (42) (31) Grand average calculated length 70 108 141 186 Increment of average 70 38 33 45 Grand average incre- ment of length 70 38 34 31 Accumulation of aver- age increments 70 108 142 173 3 Increments in parentheses. 75 Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Garden Bluff Collected on July 10 and July 16, 1958 Females Age No. of 7__ Length (millimeters) at End of Year I Group Fish 1 6 7 8 III 76 73 106 140 ... ... ... ... ... (33)" (44) IV 16 67 115 155 184 ... ... ... ... (48) (40) (29) V 13 72 114 161 191 221 ... ... ... (42) (4'7) (30) (30) VI 4 64 107 149 185 218 246 ... ... (43) (42) (36) (33) (28) VII 1 71 118 160 205 229 259 294 ... (47) (42) (45) (24) (30) (35) VIII 1 78 127 169 213 238 260 284 308 (49) (42) (44) (23) (22) (24) (24) Grand average calculated length 72 109 145 188 222 251 289 308 Increment of average 72 37 36 43 34 29 38 19 Grand average increment of length ' 72 37 44 31 3O 27 29 24 Accumulation of average increments 72 109 153 184 214 241 270 294 T:Increments in parentheses. 76 Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Garden Bluff Collected on July 10 and July 16, 1958 Males Age Number of Le th millimeters at End of Year Group Fish 3 * 5 III 47 74 106 156 000 00. (32)‘ (30) IV 8 68 107 148 181 ... ' (39) (41) (33) V 2 71 107 151 195 223 (36) (44) (44) (28) Grand average calculated length 73 106 138 184 223 Increment of average 75 55 52 46 59 Grand average increment of length 73 33 32 35 28 Accumulation of average increments 73 106 138 173 201 5 Increments in parentheses. 7? Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Garden Bay Collected on July 11, 1958 Females Age wNumber of Length (millimeters) at End of Year Group ' Figh 1., 3 III 16 72 113 161 ... (41)‘ (48) IV 2 73 104 159 190 (31) (55) (31) Grand average calculated length 72 112 161 190 Increment of average 72 46 49 29 Grand average increment of length 72 40 49 31 Accumulation of average increments 72 112 161 192 Males ge umber 0 en th mi ime ers a ear Group Figh 1 #3 4 5 III 5 68 101 151 000 000 (33) (30) IV 4 62 100 151 185 ... (38) (51) (34) V l 66 103 169 202 225 (37) (66) (33) (23) Grand average calculated length 65 101 143 188 225 Increment of average 65 36 42 45 37 Grand average increment of length 65 35 42 34 23 Accumulation of aver- age increments 65 100 142 176 199 TIncrements in parentheses. 78 Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Gray's Springs Collected on July 12 and July 15, 1958 Females Age NumBer of Eenétfi (mizlimeters) at End of Year Group Fish; 1 ‘ 3 4 I 2 66 0.. .0. .0. II 6 62 100 ... ... (38)‘ III 53 72 113 146 ... (41) (33) IV 3 66 119 155 190 (53) (36) (35) Grand average calculated length 71 112 146 190 Increment of average 71 41 34 44 Grand average increment of length 71 41 33 35 Accumulation of average increments 71 112 145 180 Mgles ng NumBer of Le%gth (miIIimetgrs) at E53 of Yggg Group Figh 2 5 4 5L III 7 75 108 146 ... ... (33) (38) V 1 66 107 137 165 190 (31) (30) (28) (25) Grand average calculated length 74 108 145 165 190 Increment of average 74 34 37 20 25 Grand average incre- ment of length 74 33 37 28 25 Accumulation of average increments 74 107 144 172 197 : Increments in parentheses. 79 Calculated Total Length at the End of the Different Years of Life for Yellow Perch from Kates Bay Collected on July 13 and July 15, 1958 Females e umber o e th m1 imeters at d o ear Group Fisp: _p 4 5 III 79 72 106 146 ... ... (34)‘ (40) IV 11 68 119 153 188 ... (51) (34) (35) V 3 64 108 162 195 223 (44) (54) (33) (26) Grand average calculated length 71 108 147 190 223 Increment of average 71 37 39 43 33 Grand average incre- ment of length 71 36 40 34 26 Accumulation of average increments 71 107 147 181 207 Males . Age _Number of, Length (millimetggsjat End of Year Group Fish 1 2 13 4 III 36 69 104 140 ... (33) (36) IV 9 69 108 154 185 (39) (46) (31) Grand average calculated length 69 105 143 185 Increment of average 69 36 38 42 Grand average incre- ment of length 69 36 38 31 Accumulation of average increments 69 105 143 174 : Increments in parentheses. APPENDIX B Multiple Range Test The mean KTL’ or coefficient of condition values, de- rived from five sample areas were subjected to an "F" test to determine whether area differences existed. The "F" test showed statistical differences, and the Multiple Range test as described by Duncan (1955, 1957) was performed tockmen- mine between which areas these differences occurred. This test is designed to group means that have unequal numbers of Observations yet are not significantly different. The procedure is as follows: Section A, is a preliminary analysis of variance to determine the error standard deviation, "s". Section B, is the computation of a critical value, R'p. This value is found by multiplying the "s" value from Section A by a Zp value which is obtained from a table 0f Studentized "t" values by Duncan (1955). Section C, is the coding of sample means with respect to ascending magnitude. The number in parentheses is the number of observations (a replications) used to determine the mean. - go - 81 Section D, is the test sequence. The lowest mean value is subtracted from the highest and the difference is altered to a prime value by multiplying it by Aij' A13. =Ef?;/(ri + 17;) Where: r1 = number of observations of lower mean and r3 = number of observations of higher mean. The prime values are then compared to the criti— cal value, Zp, corresponding to the number of means lying between the two means being tested, plus two. If the prime value does not exceed the Zp value, then the means being tested along with those intermediate ones are not significantly different provided a larger replication number is not present between the two means being tested. If this is the case, then the test must be continued to see if the mean with the larger number of observations will be excluded from the group. If the prime value does exceed the Zp value, then the test continues using the largest mean and the next smallest one. The test sequence 82 is brought to a close after all possible combi- nations of non-different mean groups are ob- tained. See Tables 12 and 13 for actual data analysis by the Multiple Range test. LITERATURE CITED Bangham, Ralph V. 1955. Studies on fish parasites of Lake Huron and Manitoulin Island. Am. Mid. Nat., Vol. 53, NO. 1, Pp. 184-194. Carlander, Kenneth D. 1950. Growth rate studies of saugers, Stizostedion canadense (Smith) and yellow perch, erca flavescens (Mitchill) from Lake of the floods, MInnesota. Trans. Am. Fish. 800., Vol. 79 (1949). PP- 50-42. Coots, Millard 1956. The yellow perch, Perca flavescens (Mitchell), in the Klamath River, Calif. Fish and Game, Vol. 42, NO. 7, pp. 219-228. Duncan, David B. 1955. Multiple range and multiple F tests. Biometrics, Vol. 11, No. 1, pp. 1—42. 1957. Multiple range tests for correlated and heteroscedastic means. Biometrics, Vol. 13, NO. 2’ Pp. 164-176. El-Zarka, Salah E. 1958. Fluctuations in the population structure of yellow perch, Percg flavescens (Mitchell), in Saginaw Bay, Lake Ruron. Rh.D. thesis, University of Michigan. Fischthal, Jacob H. 1945. Parasites of northwest Wisconsin fishes. Trans. Wisc. Acad. Sci., Arts, and Lett., Vol. 57, PP. 157-220. - 83 - Fraser, C. M. 1917. On the scales of the spring salmon. Cont. to Canadian Biology. Supplement to the 6th annual report of the Dept. of Naval Services, Fisheries Branch, pp. 39-52. Hile, Ralph 1954. Changing concepts in the fishery research on the Great Lakes. Proc. Gulf and Carib- bean Fisheries Institute, 6th annual session (1933). pp- 64-70. Hile, Ralph, and Frank W. Jobes 1941. Age, growth, and production of the yellow perch, Perca flavescens (Mitchill), of Saginaw Bay. Trans. Am. Fish. Soc., Vol. 70 (1940), pp. 102-122. 1942. Age and growth of the yellow perch, Perca flavescens (Mitchill), in the flisconsin waters of Green Bay and northern Lake Michi- Hile, Ralph, George F. Lunger, and Howard J. Buettner 1953. Fluctuations in the fisheries of State of Michigan waters of Green Bay. Fish. Bull. No. 75, U. S. Fish and Wildlife Serv., V01. 54, PP. 1-540 Hopkins, S. H. 1934. The Papilose Allocreadiidae. Ill. Biol. Monographs, Vol. 13, No. 2, pp. 65-74. Jobes, Frank W. 1952. Age, growth, and production of yellow perch in Lake Erie. Fish. Bull. No. 70, U. S. Fish and Wildlife Service, Vol. 52, pp. Joeris, Leonard S. 1957. Structure and growth of scales of yellow perch of Green Bay. Trans. Am. Fish. Soc., Vol. 86 (1956), pp. 169-194. 85 Lee, Rosa M. 1920. A review of the methods of age and growth determination in fishes by means of scales. Min. Agric. and Fish., Fish. Invest., Ser. V0, VOle 4', N00 2’ pp. 1-320 Langford, R. R. and W. R. Martin 1941. Seasonal variations in the stomach contents and rate of growth in a population of yel— low perch. Trans. Am. Fish. Soc., Vol. 70 (1940), pp. 436-440. Meyer, Marvin C. 1954. The larger animal parasites of the fresh- water fishes of Maine. Fishery Research and Management Division Bulletin No. 1. Miller, Robert R. 1957. Origin and dispersal of the alewife, Alosa pseudoharenggg, and the gizzard shad, Dorosoma cepedianum, in the Great Lakes. Trans. Am. Fish. Soc., Vol. 86 (1956), pp. 97-111. MOffett, J. No and. B. P. Hunt 1944. Winter feeding habits of bluegills, Lepomis macrochirus Rafinesque, and yellow perch, Perca flavescens (Mitchill), in Cedar Lake, Nashtenaw County, Michigan. Trans. Am. Fish. Soc., Vol. 73 (1943), pp. 231-242. / ‘Pearse, A. S. 1924. The parasites of lake fishes. Trans. Misc. Acad. Sci., Arts, and Lett., Vol. 21, pp. Pycha, Richard L. and Lloyd L. Smith, Jr. 1955. Early life history of the ellow perch, Perca flavescens (Mitchill , in the Red Lakes, Minnesota. Trans. Am. Fish. Soc., Vol. 84 (1954), pp. 249-260. 86 Smith, Stanford H. 1954. A method of producing plastic impressions of fish scales without the use of heat. Prog. FiSh-Culto’ V01. 16, NO. 2, pp. 75.78. Snedecor, George W. 1956. Statistical Methods. The Iowa State College Press, Ames, Iowa, 534 pp. Turner, Clarence L. 1920. Distribution, food and fish associates of young perch in the Bass Island region of Lake Erie. Ohio Jour. Sci., Vol. 20, pp. Van Cleave, H. J. and J. F. Mueller 1932. Parasites of the Oneida Lake fishes. I. Descriptions of new genera and new species. Roosevelt Wildlife Annals, Vol. 3, pp. 1-71. 1934. Parasites of Oneida Lake fishes. III. A biological and ecological survey of the worm parasites. Roosevelt Wildlife Annals, Vol. 3 3 PP 0 161-554 0 Wallin, 011e 1957. On the growth structure and developmental physiology of the scale of fishes. Inst. of Freshwater Res., Drottningholm, No. 38, pp. -385-447. Whitney, R. R. and K. D. Carlander 1956. Interpretation of body-scale regression for computing body lengths of fish. ‘Jour. Wild. M813... Vela 20, NO. 1, Pp. 21-270 HICHIGRN STRTE UNIV. LIBRQRIES \IHIIIIHNIHIIIllllmlll‘llllHlHlll||l|||H|||l|||||||3|l|| 31293102774803