A COMPARESON OF TWO POPUMTIONS OF WHITEFISH. Cgrggonus. W {MiTCHIkLIr IN THE MUNlSlNG BAY AREA GP LAKE SUPERK’R 111053: for (Phil Dow :35 M. S. MJECHIGAN STATE UNIVERSITY Samar: Rabat-t "Gary 2%: A -Jp. A- in HQ”: 1‘, ABSTRACT A COMPARISON OF TWO POPULATIONS OF WHITEFISH. Coregonus clupeaformis (MITCHILL), IN THE MUNISING BAY AREA OF LAKE SUPERIOR by James Robert Clary All of the fish used in this study were taken by pound nets and by gill nets. Collections were made during the months of June. July. and October of 1961, and May of 1962. Additional data were obtained from collections made in the same area in July 1957 and May 1958. The calculated growth of the fish under study indicated that two populations of Whitefish exist in the Munising Bay area, in so far as the rate of growth is concerned (slow and fast growing). The length-weight relations of the two popu- vlations were compared and found to be significantly different. The slow growing Whitefish weigh less than fast growing white- fish of the same length. The total length-standard length relations of the fast and slow growing whitefish less than 350 millimeters standard length were compared and found to be significantly different, the tail lengths of the slow growing Whitefish being more variable than those of the fast James Robert Clary growing whitefish. Morphometric measurements were taken from both populations. Statistical analysis indicated that the slow growing whitefish have longer heads than fast growing whitefish of the same length, while the fast growing white- fish are deeper in the body. The distributions of the two populations have not been determined. But, the fast growing whitefish appear to inhabit the waters surrounding Munising Bay, while the slow growing whitefish seem to be concentrated in the bay. A COMPARISON OF TWO POPULATIONS OF WHITEFISH, Coregonus clupeaformis (MITCHILL), IN THE MUNISING BAY AREA OF LAKE SUPERIOR BY James Robert Clary A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Fisheries and Wildlife 1962 y/W'W gm Kai/”(K DEDICATED TO MY PARENTS ACKNOWLEDGEMENTS The writer wishes to express his sincerest thanks to Dr. Eugene W. Roelofs under whose able guidance this study was undertaken and carried to completion. His encouragement and criticisms were invaluable to the success of this study. Thanks are also due to Dr. Phillip J. Clark for his advice on statistical procedures. The writer is indebted to Mrs. Francis Baldassarre for her meticulous review of the manuscript: To Messrs. Phillip, Joe, Paul, and Jerome VanLandschoot who gave so generously of their time and equipment in collecting the whitefish so necessary for this study. To Mr. Isaac Robere for his help in collecting many of the fish used in this study. The writer is grateful to the Michigan State Agri- cultural Experiment Station for their grant which made this study possible. To Miss Bonnie Bauman, my wife-to-be, for her patient understanding all during the study. And to all of the many people who must remain unnamed, my deepest thanks. iii TABLE INTRODUCTION . . . . . FIELD METHODS . . . . . .2. AGE DETERMINATION . . . . GROWTH DETERMINATION LENGTH‘WEIGHT RELATION . . OF CONTENTS TOTAL LENGTH-STANDARD LENGTH RELATION . MORPHOMETRIC MEASUREMENTS Head Length Dorsal-Pectoral Distance DISCUSSION . . . . . . SUMMARY . . . . . . . . . . LITERATURE CITED . . . . . iv Page 10 18 25 34 35 35 41 43 45 Table 10. LIST OF TABLES Growth in length Of Whitefish in Munising Bay, Lake Superior and other Great Lakes waters . . . . . . . . . . . . . Dates, collections. gear used, and numbers Of whitefish collected.. . . . . . . . . . . Average calculated lengths attained.by the age groups at the end Of each year of life for fast growing whitefish . . . . . . . . . Average calculated lengths attained by the age groups at the end Of_each year of life for slow growing whitefish . . . . . . . . . Regression coefficients of Munising Bay Whitefj-Sh O O O O O O O O O O O O O O I 0 Analysis of covariance of length—weight relationships Of fast growing Munising Bay whitefish . . . . . . . . . . . . . . . . Analysis Of covariance of length-weight relationships Of fast and slow growing Munising Bay whitefish . . . . . . . . . Calculated weights Of fast and slow growing whitefish from the Munising Bay area . Calculated weights of slow growing whitefish from the Munising Bay area in June 1953 (Edsall) and October 1961 . . . . . Calculated weights at the end Of each year of life Of Munising Bay whitefish, slow and fast growing populations, . . . . . . Page 12 13 «16 19 20 22 23 24 Table Page 11. Analysis of covariance of total length- standard length relationships of fast growing whitefish less than 350 millimeters standard length . . . . . . . . 27 12. Analysis of covariance of total length- standard length relationships of fast -growing whitefish between 350 and 449 millimeters standard length . . . . . . . . 29 13. Analysis Of covariance Of total length-standard length relationships Of fast and slow growing Munising Bay whitefish . . . . . . 30 14. Total length-standard length regressions_ of Munising Bay whitefish . . . . . . . . . 32 15. Total length-standard length relationships of fast growing Munising Bay whitefish . . 33 16. Analysis of covariance of head lengths of fast and slow growing Munising Bay white- fish . . . . . . . . . . . . . . . . . . . 36 17. Analysis Of covariance Of dorsal-pectoral distance of fast and slow growing Munising Bay whitefish . . . . . . . . . . . . . . . 39 vi LIST OF FIGURES Figure Page 1. Munising Bay, Lake Superior. showing sample areas . . . . . . . . . . . . . . . 4 2. Typical regression line used for growth' comparisons Of Munising Bay whitefish . . . 15 3. General growth in length of Munising Bay whitefish . . . . . . . . . . . . . . . . . 17 4. fHead length-total length relationships of Munising Bay whitefish . . . . . . . . . . 37 5. Dorsal-pectora1--total length relationships of Munising Bay whitefish . . . . . . . . . 4O vii LIST OF APPENDICES Appendix Page A. Length Frequency Distributions of Munising Bay Whitefish . . . . . . . . . . . . . . . 47 B. Original Data Relating to Weights and Measurements Of Munising Bay Whitefish . . 53 viii INTRODUCTION A population of relatively slow growing whitefish. Coregonus clupeaformis (Mitchill), in Munising Bay, Lake Superior was discovered in 1957 by investigators at Michigan State Universityi' Since only a few specimens were available, no further study was made of these fish at that time. Edsall (1960) analyzed data collected by the United States Bureau of Commercial Fisheries in 1953. The results of Edsall's work indicated that the Munising Bay whitefish had a slower growth rate than any whitefish previously found in the Great Lakes (Table 1). He determined that they rarely reached the legal minimum commercial length of 17 inches. Evidence for the existence of a fast growing population Of whitefish is provided by a commercial fishery in the Munising area, which must depend upon fishes other than those of the slow growing population. The purpose of this study was to establish the existence of more than one population Of whitefish in the Munising Bay area and to compare their growth rates and certain morpho- metriC«features. Munising Bay, the site of this study. is located 100 .Asmmflv mmonom .cmmssoaz mxmq “flammav Dams Eonm omummom .oflhmuso mxmq “Ammmav :mumoo cm> Eoum .aousm mqu “Amvmav maflm cam cmumoo cm> .mfium wxma “Aommav Hammom .HOflHmmsm mxmq “Dunn mo moonsom m.mm u- m.mm o.a~ v.o~ H.mH m.sa «.ma o.~H ¢.m .. u- oflumuco mxmq N.MH m.m 0.5 m.¢ .mH xom nusom m.sa m.mH ¢.m O.m qumo mam mam ommflsofiz wxmn 6.6N m.m~ m.mm m.v~ m.m~ m.m~ ¢.Hm «.ma H.6H m.NH m.m o.m conga wxmq o.¢m m.¢m s.mm m.m~ m.~m H.mm ¢.Hm s.om o.ma H.mH H.6H s.mH m.o mflum mxmq 0.0H h.mH ¢.mH ¢.¢H m.MH m.NH H.NH m.HH m.OH H.0H v.m v.m N.b m.m HOHHOQDw mxmq ga ma NH AH OH m m h o m g m N H mwxmfl umwnw Owed mo Ham» mo com um Ammnucflv mnpmsmq Hmuoe omumasoamo Ommum>m mmu4 .mumumB mwxmq ummuw Hmfiuo pom Hoflummsm mxmq .mmm msflmflcsz CH SmflmmuHSB mo numcma GA QDBOHO .H manna 3 miles west of Sault Ste. Marie, Michigan on Lake Superior (Figure l). ’3 A, Figure l. Munising Bay. Lake Superior, showing sample areas. Murray Bay Murray (/qu 1m) 923R: East Channel SAND West (areas! 193;) m) mun- Channel Jun! mz < nu (M47 ”53) JULY My) ("d-71947) Powell (2:?) Munising Bay Point 3%y N’ If E FIELD METHODS All of the fish used in this study were taken by pound nets with 5 1/2" stretched mesh and by gill nets with 2 1/2" stretched mesh. Collections were made during the months of JUne, July, and October of 1961, and May of 1962. Some data were also Obtained from collections made in the same area in July 1957 and May 1958. All weights and measurements were taken by the writer, except those in the July 1957 and May 1958 collections. The locations of the nets used for each collection are indicated in Figure l. The type of net employed and number Of fish caught in each collection are listed in Table 2. At the beginning of the study an attempt was made to weigh and measure the fish on board the boat used to lift the nets; this proved to be unsatisfactory due to the constant motion of the boat. Therefore, all subsequent measurements were made on shore after the boat had docked. The measurements which were made are as follows: TotglfLength. Measured from the tip of the snout to the tip of the caudal fin with the lobes compressed to give the maximum possible measurement. Table 2. Dates, collections, gear used, and numbers of whitefish collected for age- growth and morphometric studies from Munising Bay area. Date Locality Gear Number,of fish 1957 July 11 West Channel Pound nets 300 *(1-300) 1958 May 23 West Channel Pound nets 76 *(1-76) 1961 June 21 west Channel Pound nets 64 *(1-59) (104-109) Mid Channel Pound nets 22 *(60-82) East Channel Pound nets 22 *(83-103) (110-111) 'July 19 West Channel Pound nets 80 *(1-43, 86-122) Middle Channel Pound nets 14 *(44-53) East Channel Pound nets 10 *(44-58) Trout Bay Pound nets 15 *(70—85) Oct. 26 Murray Bay Point Gill nets 129 *(1-129) Powell Point Gill nets 29 *(130—159) Sand Point Gill nets 41 *(160-201) *Catalogue numbers. Standard Length. Measured from the tip of the snout to the end of the last vertebra Head Length. Measured from the junction of the premaxillaries (tip of the snout) to the extreme bony margin Of the operculum, excluding the opercular membrane Dorsal-Pectoral Distance. The distance between the origins Of the dorsal and pectoral fins. Length measurements were made on a conventional fisheries measuring board. Unless otherwise specified, all measurements are given to the nearest millimeter. Head lengths and dorsal-pectoral distances were taken with needle- point dividers. This distance was then transferred to the meter stick on the measuring board and read to the nearest millimeter. Weights were taken on a spring balance and read to the nearest ounce, with the exception of the May 25, 1962 collection which was weighed on a Hobart spring scale. Scale samples were taken from the left side of the fish, just below and anterior to the dorsal fin but above the lateral line. Some difficulty was encountered in obtaining scales from this key area when the fish were captured in gill nets, as the netting tended to scrape the scales from the fishes' body. (In these instances, scale samples were taken as close to the key area as possible. The scale samples from each fish were preserved in small envelopes and all data pertinent to that fish were recorded on the envelope. AGE DETERMINATION Scale impressions were made on cellulose acetate 0.020" thick, utilizing a roller press constructed like the one described by Smith (1954). These impressions were examined with a Bausch and Lomb Tri-Simplex microprojector under a magnification Of 43 times. The age of each fish is given in terms of completed years of life, a determination reached by counting the number Of annuli on the scale. The distance from the focus to each annulus was measured along the greatest radius of the scale and recorded on a calibrated IBM scale card. Each fish is considered to have passed into the next highest age-class after January lst. Therefore, all fish captured after that time were assigned a virtual annulus at the edge of the scale until the actual annulus was formed. This procedure affected only the two groups of fish collected in May 1958 and 1962, as the writer determined that annulus formation occurs in late May or early June. GRGN TH DETE RMINATI ON Growth computations were based on the assumption that after the completion of the first annulus, scale growth is directly proportional to fish growth. A direct proportion nomograph, as described by Carlander and Smith (1944), was utilized for growth determination. Van Oosten (1923) deter- mined that the total length of whitefish at the time of scale formation is between 35 and 40 millimeters. By a scale diameter-total length relation, Edsall (1960) determined that the intercept value was 37.74 millimeters for Mnnising Bay whitefish. In this study, however, the intercept value, "c" was arbitrarily set at 40 millimeters. This value was used because the exact intercept value of the body-scale regression might be distorted by Obtaining scale samples from different areas on some fish. It is thought by the writer that the use of 40 millimeters as the intercept value will not greatly distort the calculated growth values. 10 CALCULATED GROWTH The calculated growth of the fish under study indicated that two populations Of whitefish exist in the Munising Bay area, in so far as the rate of growth is concerned. Although the July 1957, June 1961, and July 1961 collections contained a few individuals from the slow growing population of fish, they consisted primarily of fast growing individuals. For the purpose of this study, having first eliminated the few.slow growing individuals from all computations Of those collections, the writer will refer to them as collections of fast growing fish. In the same manner, the October 1961 collection was pruned of the few fast growing individuals which it contained. Thus, the collections can now be designated as fast and slow growing throughout the paper. The number of fast and slow growing individuals excluded from the collections' computations are indicated in Tables 1 to 5 in the appendix, the length- frequency distributions for each Of the collections. The calculated length at the end of each year of life for the fast and slow growing populations is listed in Tables 3 and 4, respectively. The growth rates of the two populations were compared 11 12 mmfi mov o¢¢ mmm Nam mwm th wmwum>m Nae Hme mmm mmm new mam ems m HH> New mas mmm awn «mm med Hm . H> use Ham men mmm and men > mam mam mew Has «om >H mam wen mes mm HHH mum mas ma HH m s o m e m m H swam ozone m mom How» mo com um AmHmumEHHHHEV Spmcwa Hmuou omumasoamo HTQEDZ mmsomo mom .HOHHmmDm Oxmq .>mm madness: CH wooeuumaaoo Homa hash .Hmma mash .hmma mash .mmma was Scum ow>flum© smammuflg3 msflzonm ummm Hom mmaa m.Hmm> some no use may um msoum mom mfiu an omsflmuum msumsma nmumasuamo mmmum>¢ .m manna, 13 0mg mmv 0N¢ Nmm Hmm 0mm me Nom th mmN osN OHN vhH NmH .Hm>¢ owe mmw 0mg me mmm hmm Hmm HHm omN moN NMN mON NwH mMH H >HN II II II II II II II II II II II II II o HHHN wa mmm mum mwm th mom mmN omN NNN mmH 50H OMH w HHN mmm Nom ovm ONm th obN omN mNN mmH me NMH o Hx mmm mHm mmN mbN me va vHN mmH me omH NH N 0mm ¢Hm omN mON mvN wHN mmH mmH MNH vH NH mNm mom omN mmN mNN HON 50H mNH mm HHH> MHm NmN moN 5mm hON th mMH hm HH> mom th bvN HHN MhH OMH vs H> .omN ooN «NN HmH NMH 5N > mmN NmN OON hMH NH >H mom ¢HN OMH m HHH vH mH NH HH 0H m m h o m g m N H SmHm msoum mmbomw mwfl HOQEDZ mmfl .HomH .uoo AmsHBOHm BOHDV zmHMTUHSB ham mchHszz mom OMHH m.um0> some no one mg» no masoum 0mm 03» ha owsHmuum mnumcwH UmumHDUHmu mmmum>< .v OHQOB 14 by a "t" test (Snedecor, 1946) to determine if they were significantly different. For this test, the July 1961 collection Of fast growing fish was compared to the October 1961 collection of slow growing fish. Five-year—old fish were chosen for the test as they were the oldest group of fast growing fish in which could be found enough individuals to permit comparison by the "t" test. Twenty-seven 5-year—old fish from each collection were chosen without reference to length. The growth rate of each individual fish was plotted as follows: The age was plotted on a logarithmic scale on the x-axis against the back-calculated length at each age on the Y—axis (Figure 2). A regression line was calculated for the five plotted points (back—calculated lengths at ages I, II, III, IV, V). The slopes (regression coefficients) of the 27 lines representing each population were totaled, and the averages were obtained (Table 5). The two averages were then compared and a "t" value of 9.37 was Obtained. This value indicates that the growth rates are significantly different at the 0.1% level. The general growth curves for the slow and fast growing populations of whitefish are shown in Figure 3. 15 mesa mo Dam» .smammuasz Nam msHmHsaz mo usomHnmmeoo nuzonm you new: msHH sOHuumHmmH HOUHQ>B .ov .om .ONH LowH ICON ..o¢~ .omN ..0Nm .N mHDmHm stqemrttru u; quuaq {2401 paaetnoteo 16 Table 5. Regression coefficients Of Munising Bay whitefish (used in growth rate comparison of fash and slow growing populations). Fast Growing Population Slow Growing Population 29.837 22.527 30.515 20.670 49.071 23.855 30.755 26.606 34.841 20.574 30.242 27.347 31.580 22.191 48.602 29.253 42.386 23.355 35.086 28.042 33.446 27.561 37.237 20.826 35.073 23.156 33.678 19.017 29.094 20.421 31.065 21.509 42.937 18.641 32.717 20.393 26.609 17.915 29.104 19.392 31.306 16.044 35.076 25.963 31.387 24.184 43.587 25.434 34.121 24.294 35.903 20.265 33.888 14.373 Average Fast Growing Population = 34.783 Average Slow Growing Population = 22.363 17 omen mo Ham» EHHHN HHun HM N NH HHS HH> H> >~ >HHHH H H COHumHDmom GOHumHDmom mGHBOHO 30Hm mstoHO ummm .smHmmuH33 >mm msHmHssz mo sumcmH CH nu3oum-Hmumst .m mhsmHh _.oma .omH room IOGN .omN vomm .omm roow uo¢¢ .omv SIGQBWTTIIW u? uzfiueq IEQOI Denatnoteo L EN GTH-WE I GHT RELATI ON The length-weight relation of fish having a constant form and specific gravity is W = CL3, where W = weight, C = a constant, and L = length. However, this relation is rarely encountered in nature due to the variability in form and weight of different species Of fish. A more accurate method Of computation, as described by Hile and Jobes (1942), involves the use of the equation W = an. The length—weight regression was determined for each collectiOn by the method of least squares using the logarithms of the lengths and weights. The length-weight relations for each collection of fast growing fish were compared by analysis of covariance (Snedecor, 1946) to determine if a common line could be used to describe all Of the collections. The results (Table 6) indicate that the length—weight regressions are not significantly different: therefore, they can be described by the following equation, where W = weight in ounces and L = length in centimeters: Log W = -3.86768 + 3.23033 Log L The length-weight relation for the October 1961 col- lection Of slow growing fish was significantly different from the relation derived from the combined collections of fast 18 19 Table 6. Analysis of covariance of length—weight relations (fast growing collections) Munising Bay whitefish. Notation May 1958 July 1957 June 1961 July 1961 Totals 2 2x .0527 .7857 .4578 .5258 2.0232 Zyz .6329 8.4535 5.3824 5.7512 22.2515 ny .1720 2.5129 1.5366 1.6769 6.5356 Slope 3.2634 3.1981 3.3567 3.1891 3.2303 n 76 258 102 173 609 Zdz .0717 .4170 .2245 .4035 1.1394 To test for significant differences in the slopes: $2 = .003003 $2 = .001858 1 2 2 s1 3 F = 2 = 1.6163(601) defrees Of freedom. 3 2 1.6163 is less than 2.62, therefore the slopes are not significantly different. ‘ To test for significant differences in the elevations: 32 = .00461 $2 = .00186 3 2 4 83 3 F - 2 = 2.473 (604) degrees of freedom. s 4 2.473 is less than 2.62, therefore the elevations are not significantly different. 20 growing fish (Table 7). :Therefore, the following equation must be used when predicting weight for the slow growing whitefish: Log W = -3.7816 + 3.12152 Log L The predicted weights Obtained from the length—weight relations for the fast and slow growing pOpulations are listed in Table 8. These indicate that slow growing whitefish always weigh less than fast growing whitefish of the same length. At first it may be presumed that the difference is a result Of seasonal variation Of the length-weight regressions, but Edsall (1960) based his length-weight relation on fish captured in June of 1953, and the predicted weights obtained frOm.his relation and this writer's are not appreciably different (Table 9). Since the writer's length-weight relation for the fast growing fish is based on collections made at the same time of year as Edsall's, it seems apparent-that the leanrowihg whitefish.do in fact weigh less per given length than.thef fast growing whitefish. The calculated weights at the end Of each year Of life for bOth populations of fish are shown in-TableflOr' 21 Table 7. Analysis of covariance of length-weight relations of Munising Bay whitefish (fast and slow growing). 1,—7 Notation Fast growing Slow growing Totals 2x2 2.0232 .3040 3.7566 2y2 22.2515 3.4185 47.4130 ny 6.5356 .9489 13.0594 Slope 3.2303 3.1216 3.4764 n 609 198 807 2d2 1.1394 .4564 2.0133 To test for significant differences in the slopes: 82 = .00316 $2 = .00199 1 2 2 s1 1 F = 2 = 1.587 (803) degrees of freedom. 3 . 2 ~l.587 is less than 3.86, therefore the slopes are not significantly different. To test for significant differences in the elevations: 2 2 s3 — .41435 34 — .00199 2 83 1 F - 2 = 208.3208 (804) degrees of freedom Os 4 208.3208 is greater than 6.70, therefore the elevations are significantly different at the 0.1% level. 22 Table 8. Calclulated weights of fast and slow growing white- fish from the Munising Bay area. Total length Calculated weight in ounces 1n millimeters Fast growingl Slow growing2 250 4.45 3.94 260 5.05 4.45 270 5.70 5.01 280 6.41 5.61 290 7.18 6.26 300 8.02 6.96 310 8.91 7.71 320 9.87 8.52 330 10.91 9.37 340 12.01 10.29 350 13.22 11.26 360 14.45 12.30 370 15.78 13.40 380 17.20 14.56 390 18.72 15.79 400 20.30 17.09 410 21.99 18.46 420 23.77 19.90 430 25.64 21.42 440 27.62 23.01 450 29.70 24.68 lFast growing length—weight relation based on combined July 1957, May 1958, June 1961, and July 1961 collections. 2Slow growing length-weight relation based on October 1961 collection. 23 Table 9. Calculated weights of slow growing whitefish from the Munising Bay ares in June 1953 (Edsall) and October 1961. June 1953 (Edsall) October 1961 Average total Average Calculated Calculated length weight weight weight (inches) (ounces) (ounces) (ounces) 7.3 1.4 1.5 1.55 7.5 1.6 1.6 1.67 8.2 2.1 2.2 2.23 8.8 2.8 2.7 2.77 9.2 3.1 3.1 3.19 9.7 3.6 3.7 3.77 10.2 4.2 4.4 4.41 10.7 5.1 5.1 5.12 11.2 6.1 5.9 5.90 11.7 6.9 6.7 6.76 12.3 7.8 7.9 7.90 12.7 .8.9 8.9 8.73 13.2 10.2 9.9 9.85 13.7 11.4 11.1 11.10 14.3 12.4 12.7 12.64 14.7 14.1 13.9 13.79 15.2 16.3 15.4 15.31 15.7 16.7 17.1 16.93 16.4 16.1 19.6 19.38 16.8 20.8 21.2 20.91 17.4 26.8 23.7 23.34 24 Table 10. Calculated weights at the end of each year of life of Munising Bay whitefish, slow and fast growing populations. Yeiifgf Slow growing Fast growing Calculated Increment Calculated Increment weight in weight weight in weight (ounces) (ounces) (ounces) (ounces) I .54 .54 1.33 1.33 II 1.27 .73 4.06 2.73 III 2.29 1.02 9.10 5.04 IV 3.47 1.18 17.94 8.84 V 4.73 1.26 27.62 9.68 VI 6.06 1.33 33.71 6.09 VII 7.11 1.05 37.08 3.37 VIII 8.27 1.16 IX 9.37 1.10 X 11.37 2.00 XI 16.05 4.68 XII 19.90 3.85 XIII 26.25 6.35 XIV 30.59 4.34 (weights are from the length—weight relation derived from the combined May 1958, July 1957, June 1961, and July 1961 collections for the fast growing population: and OctOber 1961 for the slow growing population.) TOTAL LENGTH-STANDARD LENGTH RELATIONSHIP The total length—standard length relationship makes it possible to calculate the average expected total lengths from actual standard length measurements. It also provides an indirect measurement of tail length, but since tail growth is not constant throughout the life of whitefish (Van Oosten and Hile, 1949), those under study were divided into two groups according to size. A separate relationship was then derived for each group. One group included all fish with standard lengths of less than 350 millimeters. The other, group contained all fish with standard lengths of between 350 and 449 millimeters. The total length—standard length relationship was derived for each size group by taking the average total length Of the fish in that group and dividing it by the average standard length of the same fish. The resulting factor was then used to calculate total length from standard length. The reciprocal Of that factor can be used to calculate standard length from total length. The relationship for the slow growing whitefish was Obtained from the October 1961 collection. This collection 25 26 consisted almost entirely Of fish with standard lengths of less than 350 millimeters. Only 4 of the 198 fish in that collection had standard lengths greater than 350 millimeters. Therefore, it was not possible to derive a total length— standard length relationship for the 350 to 449 millimeter size group. The total length-standard length relationship for the slow growing whitefish with standard lengths of less than 350 millimeters is: Total length = 1.206 Standard length The total length—standard length relationships for the fast growing whitefish were based upon the June 1961 and July 1961 collections (standard length measurements were not taken in 1957 or 1958). Two relationships, one for each size group, were calculated for each collection. The total length-standard length relations of the fast growing fish with standard lengths of less than 350 millimeters were 'compared by analysis of covariance. The results of the test indicate that the two relationships are not significantly different (Table 11). Thus, all of the fast growing fish with standard lengths of less than 350 millimeters can be described by the following relationship: Total length = 1.1985 Standard length Similarly, the total length-Standard length relationship 27 Table 11. Analysis of covariance of total length-standard length relationships of fast growing whitefish less than 350 millimeters standard length, June 1961 and July 1961. f Notation July 1961 June 1961 Totals 2x2 1477.46 379.26 2093.31 Zy2 1975.02 481.03 2794.75 ny 1699.90 423.86 2406.84 Slope 1.15055 1.11760 1.14978 n 115 45 160 2d2 19.19 7.32 27.41 To test the slopes for significant differences: 2 2 s1 = .37 2 s2 = .17 S1 1 F - 2 = 2.176 (156) degrees of freedom. s 2 2.176 is less than 3.91, therefore the slopes are not significantly different. To test the elevations for significant differences: 2 2 s3 - .52 2 s4 — .18 s3 1 F = 2 = 2.9714 (157) degrees of freedom. 3 4 2.9714 is less than 3.91, therefore the elevations are not significantly different. 28 of the 350 to 449 millimeter size group were compared by analysis of covariance (Table 12). The results of this test indicate that the fast growing fish in that size group can be described by the following relationship: Total length = 1.1919 Standard length The total length—standard length relationships of the fast and slow growing whitefish less than 350 millimeters standard length were compared by analysis of covariance to determine if they were significantly different. The results show that the slopes of the total length-standard length regression of this size group are significantly different at the 1% level (Table 13). The actual calculated values of the two relationships are not appreciably different, however. The important difference lies in the variability of the tail length. The lengths of the tails Of slow growing whitefish are more variable than are the tail lengths Of fast growing whitefish of the same total length. The total length-standard length relationships derived thus far rest on the assumption that the intercept value is zero. that is, when the total length is zero, the standard length is also zero. An intercept value does exist for the data used in this study, however, due to the absence Of'small fish in the collections. These fish normally would 29 Table 12. Analysis Of covariance of total length-standard length relationships of fast growing whitefish between 350 and 449 millimeters standard length, June 1961 and July 1961. fl Notation July 1961 June 1961 Totals 2x2 '1560.18 247.62 1922.28 2y2 2248.14 327.94 2772.44 ny 1861.16 279.56 2290.65 Slope 1.193 1.129 1.192 n 58 57 115 2d2 27.78 12.32 41.99 To test the slopes for significant differences: 2_ 2- 81 - 1.03 82 — .36 2 .81 1 F = 2 = 2.861 (111) degrees of freedom s 2 2.861 is less than 3.94, therefore the slopes are not significantly different. . To test the elevations for significant differences: s2 = 86 82 = 37 3 4 2 s3 1 F - 2 = 2.324 (112) degrees of freedom s 4 2.324 is less than 3.94, therefore the elevations are not significantly different. 30 Table 13. Analysis of covariance Of total length-standard length relationships of fast and slow growing Munising Bay whitefish. (All fish included with standard lengths less.than 350 mm.) Notation Fast growing Slow growing (June & July 1961) (October 1961) Ex? 2093.31 795.68 2y? 2794.75 1119.40 ny 2406.84 850.69 Slope ’ 1.1478 1.0591 n 160-w 192, Zdz 27.41 209.93 ‘T TO test the slopes for significant differences: 2 2 s1 — 3.62 .s2 — .68 . 2 81 1 F = 2. = 5.323 (348) degrees of freedom 8 _ 2 5.323 is greater than 3.89, therefore the slopes are significantly different at the 5%rlevel. ' 31 reduce the intercept value to zero. Therefore, to determine a more accurate total length—standard length relationship, the formula for a straight line was used. This formula is: Y = a + bX, where Y = total length, a = intercept, b = slope, and X = standard length. The total length-standard length regressionsderived for the fast and slow growing fish using this formula (Table 14) were based upon the same data used in the previous relationships and analysis of covariance tests, and the initial differences were maintained. The predicted values obtained from the total length-standard length relations derived by both methods are listed in Table 15. It is apparent that the slight increase in accuracy obtained by using the intercept value does not warrant the extra work necessary to derive it. 32 Table 14. Total length-standard length regressions of Munising Bay whitefish. Fast growing population Size group Total length-standard length regression < 350 mm. Total length = 15.1 + 1.150 standard length 350 to 449 mm. Total length = 0.00 + 1.192 standard length Slow growing population Size group Total length—standard length regression < 350 mm. Total length = 37.2 + 1.069 standard length 33 Table 15. Total length-standard length relationships of fast growing Munising Bay whitefish. Number Average Average Predicted Predicted of total standard total total fish length length lengthl length2 3 286 236 283 285 4 294 242 290 293 4 307 255 306 308 5 313 259 311 313 4 325 272 326 328 3 334 278 333 335 8 346 286 343 344 4 356 295 354 354 4 363 302 362 362 8 375 314 376 376 4 383 323 387 387 8 394 331 397 396 23 405 341 408 408 48 414 350 417 417 28 423 357 426 426 8 434 362 431 431 5 447 374 446 446 13 454 378 451 451 9 465 390 465 465 5 475 399 476 476 5 485 407 485 485 l 496 416 496 496 l 500 422 503 503 1 511 433 516 516 l 525 440 524 524 1Based on total length-standard length relationships derived by dividing total length by standard length. 2Based on total length—standard length regression derived by utilizing the formula for a straight line. MORPHOMETRIC MEASUREMENTS Various workers have used morphometric measurements for distinguishing populations Of fish. Marr (1957) defines the term "population" as: A population of fish includes all individuals of a given species when there are no subspecies, or if there are subspecies, when their distributions are not discrete. It includes only all individuals of a subspecies when the distributions of the subspecies are discrete, The results of current studies point out that morpho- logically different populations of whitefish do exist in various geographic localities of the same body of water as well as in separate bodies of water. Svardson (1949) maintains that the Genus Coregonus is subject to considerable morphological variation due to environmental changes. One of the purposes of this paper is to point out differences between the two populations of whitefish inhabiting Munising Bay. These fish occupy the same area, yet they have signifi- cantly different growth rates and body proportions. Caraway (1951) compared whitefish of the same age class in his morphometric studies. Due to the extreme difference in growth rates, such comparisons are questionable for the Munising Bay whitefish because proportional body 34 35 measurements may vary with size. Therefore, through use of analysis of covariance, the comparison of the slow and fast growing populations of Munising Bay whitefish are based upon fish of the same size. Morphometric measurements were taken from 135 fish in the July 1961 collection (fast growing) and from 198 fish in the October 1961 collection (slow growing). Head Length The head length measurements of the fast and slow growing populations Of whitefish were compared by analysis of covariance. The results indicate that the two populations are significantly different at the 5% level (Table 16). The slow growing whitefish have longer heads than do fast growing whitefish of the same length. This difference is apparent in Figure 4 which contains the regression lines of each population. Dorsal-Pectoral Distance The dorsal-pectoral distance was the measurement used to depict the body depth of the fish under study. This measurement was used in preference to the depth measurement normally employed by biologists because Of the variability of the abdomen in whitefish. 36 Table 16. Analysis of covariance of head lengths of fast and slow growing Munising Bay whitefish. Notation July 1961 October 1961 Totals 2x2 2430.14 2078.39 8133.61 2y2 6712.03 7503.17 196.14 ny 360.84 344.14 1171.88 Slope .14848 .16558 .14408 n 136 198 334 Ed2 12.64 13.81 27.30 To test for significant differences in the slopes: $2 = .33 32 = .080 1 2 2 S l l . F = 2 = 4.125 (330) degrees of freedom.‘ 5 2 4.125 is greater than 3.89, therefore the slopes of the two populations are different at the 5% level. 37 mumumEHHHHE CH numcma Hmuoe O O 3 2 A. 4 p» D T410 '400 #390 L380 .370 '360 ”350 ~340 P330 ’320 >310 I300 Home amnouuo .smwmmuHEB hmm msHchsz mo mQHSOGOHDMHOH sumsmH HODODIsumcmH comm .v mustm .0m 00 Oh om sxeqemIIITw UT unfiueq peeH 38 The dorsal—pectoral distances for each population and their relation to total length were compared.by analysis of covariance. The results of the test indicate that the two populations are significantly different at the 1% level (Table 17). This difference is apparent in Figure 5. 39 Table 17. Analysis of covariance of dorsal—pectoral distance of fast and slow growing Munising Bay whitefish. Notation July 1961 October 1961 Totals 2x2 2424.77 2078.39 8094.06 Zyz 15099.46 13116.80 28216.26 ny 647.30 528.17 2471.94 Slope .26695 .2541 .3054 n 135 198 333 Zdz 32.42 27.43 80.00 To test for significant differences in the slopes: 82 = .21 s2 = 1182 l 2 2 s1 1 F = 2 — 1.1445 (329) degrees of freedom 8 2 1.1445 is less than 3.89, therefore the slopes are not significantly different. To test for significant differences in the elevations: 82 = 19.94 82 = .182 3 4 2 83 1 F = 2 = 109.56 (330) degrees of freedom s 4 109.56 is greater than 6.76, therefore the elevations are significantly different beyond the 1%.level. 4O mumumfiflaaflz CH Samson Hmuoa 00 0000000000000000000000 87 6543210987654321098765 444444444333333333322222 Hmmfl 900000 Hmma sass .amflwmuflnz sum msflmflcsz mo mmflanOHumamH numcma HmuonIIHMHouommlammHon .m wusmflm 00 on ow om . OHM . ONH OMH Odd sxaqamrttrw ur eouensra Iezoqaea—IESIOQ DISCUSSION Further research must be carried on before the distributions of the two populations can accurately be determined. The fast growing whitefish appear to inhabit the waters surrounding Munising Bay. However. a collection made in May 1962 indicates that they do move into the bay. The extent and frequency of these movements have yet to be determined. Very little information is available regarding the movements of the slow growing whitefish. They seem to be concentrated in Munising Bay; but, commercial catches indicate that they occasionally move into the west channel. Nets which were set on the east and west side of Grand Island in May 1962 failed to take any slow growing whitefish. This may be an indication that their distribution is confined primarily to Munising Bay. However, there are no apparent physical barriers which would prevent them from leaving the bay. This concentration of slow growing whitefish in Munising Bay may have resulted in it being closed to commercial fishing as a nursery area: a function which it apparently does not serve. Extensive tagging experiments are needed before the movements and distributions of the two populations can be 41 42 accurately ascertained. The writer has referred to the fast and slow growing whitefish as populations throughout the paper. This implies that heritable differences do exist between the two groups. The highly significant difference in growth rates lends credence to this implication. The continuous exchange of water which occurs between Munising Bay and its surrounding waters supports the idea that the environments are similar thus weakening any argument in favor of environmentally induced differences. However, a complete limnological study of the area is needed before the environment as a causal factor of population differences can be completely discounted. If we consider the two populations to be genetically compatiblef we must assume that they are not interbreeding. Any long term interbreeding would tend to eliminate the significant differences between the populations. Therefore. either they spawn in different areas. or at different times in the same area. Whether one accepts environment or genetics as the cause for the population differences, the fact remains that these differences are present. The need for further study is obvious. SUMMARY 1. The calculated growth of the fish under study indicated that two populations of whitefish exist in the Munising Bay area, in so far as the rate of growth is concerned. The growth rates of the two populations were compared by a "t" test and found to be significantly different at the 0.1% level. 2. The length—weight relationships were derived for each population of whitefish. The relations were compared by analysis of covariance and found to be significantly different at the 1% level. The length-weight relations indicate that the slow growing whitefish always weigh less than fast growing whitefish of the same length. 3. The total length-standard length relationships of the fast and slow growing whitefish less than 350 millimeters standard length were compared by analysis of covariance. The results indicated that the relations were significantly different. The significant difference lies in the variability of the tail length. The lengths of the tails of slow growing whitefish are more variable than are the tail lengths of fast growing whitefish of the same length. 4. Morphometric measurements were taken from 135 fast 43 44 growing fish and from 198 slow growing fish. Two such measure- ments were taken, head length and the dorsal—pectoral distance. The head length measurements of the fast and slow growing populations were compared by analysis of covariance. The results indicate that the two populations are significantly different at the 5% level. The slow growing whitefish have longer heads than do fast growing whitefish of the same length. The dorsal—pectoral distance was used to depict body depth. The distances for each population and their relation to total length were compared by analysis of covariance. The results of the test showed that the two populations were significantly different at the 1% level. 5. Further research is necessary before the distributions of the two populations can accurately be determined. The fast growing whitefish appear to inhabit the waters surrounding Munising Bay. while the slow growing whitefish seem to inhabit the Bay. This concentration of slow growing whitefish in Munising Bay may have resulted in it being closed as a "nursery area.‘ which function the Bay apparently does not serve . LITERATURE CITED Caraway, Prentice A. 1951. The whitefish, Coregonus clupeaformis (Mitchill), of northern Lake Michigan, with special reference to age, growth, and certain morphometric characters. Ph.D. thesis, Michigan State University: 1—135. Carlander, Kenneth D., and Lloyd L. Smith, Jr. 1944. Some uses of nomographs in fish growth studies. Copeia, 3:157-162. Edsall, Thomas A. 1960. Age and growth of the whitefish,- Coregonus clupeaformis (Mitchill), of Munising Bay, Lake Superior. Trans. Am. Fish. Soc., 89:323-332. Hart, John L. -l93l. The growth of the whitefish, Coregonus culpeaformis (Mitchill), Contr. Canad. Biol. and Fish., N.S., 6 (20):427-444. Hile, Ralph. 1948. Standardization of methods of expressing lengths and weights of fish. Trans. Am. Fish. Soc., 75:157-164. Hile, Ralph and Frank W. Jobes. 1942. Age and growth of the yellow perch, Perca flavescens (Mitchill), in the Wisconsin Waters of Green Bay and northern Lake Michigan. Pap. Mich. Acad. Sci Art, Lett., 27:241-266. Marr, John C. 1957. The problem of defining and recognizing subpopulations of fishes. U.S. Fish. and Wild. Service, Special Scientific Report-Fisheries, 208:1-6. Roelofs, Eugene W. 1958. Age and growth of whitefish, Coregonus clupeaformis (Mitchill), in Big Bay de Noc and northern Lake Michigan. Trans. Am. Fish. Soc., 87:190-199. Smith, Stanford H. 1954. A method of producing plastic impressions of fish scales without the use of heat. Prog. Fish-Cult., l6 (2):75-78. 45 46 Snedecor, George W. 1946. Statistical methods applied to experiments in agriculture and biology. 4th ed. Collegiate Press, Ames, Iowa, 1—485. Svardson, Gunnar. 1949. The Coregonid problem. II. Morphology of two coregonid species in different environments. Institute of Freshwater Research, Fishery Board of Sweden, Drottningholm, Report 31: 151-162. Van Oosten, John. 1923. The whitefishes (Coregonus clupeaformis). A study of the scales of whitefishes of known ages. Zool. Sci. Contr., N. Y. Zool. Soc., 2 (l7):380-412. . 1939. The age, growth, sexual maturity, and sex ratio of the common whitefish, Coregonus clupeaformis (Mitchill), of Lake Huron. Pap. Mich. Acad. Sci., Arts, and Lett., 24:195-221. Van Oosten, John and Ralph Hile. 1949. Age and growth of the lake whitefish, Coregonus clupeaformis (Mitchill), in Lake Erie. Trans. Am. Fish. Soc., 77:178-249. APPENDIX A 48 Table 1. Length frequency distribution of Munising Bay whitefish, July, 1957. Total length in AGE GROUPS millimeters II III IV V VI VII VIII IX 260-269 270-279 280-289 2 290-299 300-309 310-319 1 320-329 330-339 340-349 350-359 360-369 370-379 380-389 390-399 400-409 410-419 420-429 430-439 440-449 1 450-459 460-469 470-479 480-489 490-499 500-509 510-519 520-529 530-539 540-549 550-559 560-569 H l—‘NNNW-bO‘O‘U‘I l—l Average Total Length 297 329 Total Number of Fish 4 33 22 31 27 2 25 28 11 17 ll l—‘NuhLOCD 417 454 162 49 1 1* Ch 483 12 1* 1* 1* 1* 1* 481 560 *Designates slow growing whitefish. 49 Table 2. Length frequency distribution of Munising Bay whitefish, May 1958. Total AGE GROUP length in millimeters III IV V VI VII VIII 270-279 280-289 290-299 300-309 310-319 320-329 330-339 340-349 350-359 360-369 370-379 380-389 390-399 400-409 410-419 420-429 430-439 440-449 450-459 460-469 470-479 480-489 490-499 500-509 510-519 520-529 1 1 530-539 540-549 550-559 1 [—1 1.: HNl—‘O‘Ntoww g... {0:5wa P403P'H N [.1 [—4 '—l Average Total Length 0 - 449 456 483 Total Number of Fish 0 16 50 10 0 O 50 Table 3. Length frequency distribution of Munising Bay whitefish, June 1961. Total AGE GROUPS length in millimeter II III IV V. VI VII VIII IX X XI XII XIII H 3(- 260-269 270-279 1 280-289 290-299 300-309 1 310-319 320-329 330-339 340-349 350-359 360-369 370-379 380-389 390-399 400-409 410-419 420-429 430-439 440-449 450-459 460-469 470-479 480-489 490-499 500-509 1 510-519 520-529 1 530-539 540-549 550-559 1 N '—l 1* 1* HHwaI-‘Wubw 1* U'lwl-‘w bflwNI-J N Nub- l—‘UJNU'IkoufiUJ-bl" LA) [.4 Average Total Length 293 331 401 459 479 Total Number of Fish 4 22 38 35 8 1 0 1 l C) l *Designates slow growing whitefish. 51 Table 4. Length frequency distribution of Munising Bay white- fish, July 1961. Total length in millimeters II III ‘ IV V VI VII VIII IX X fl AGE GROUPS 260-269 270-279 280-289 290-299 300-309 310-319 320-329 330-339 340-349 350—359 360-369 370-379 380-389 390-399 400-409 2 18 410-419 44 420-429 1 21 430-439 1 440-449 1 450-459 460-469 470-479 480-489 490-499 500-509 510-519 520-529 530-539 540—549 550-559 1 560-569 570-579 1 NNI—‘wN 1* 1* NNQHNWWHH 1* 1* N OHHNNHNH w-bwl-‘O‘bw NM F‘F‘F‘H Average Total Length 304 344 410 447 449 571 Total Number of Fish 10 27 105 29 3 2 1 2 *Designates slow growing whitefish. 52 Table 5. Length frequency distribution of Munising Bay whitefish, October 1961. Total AGE GROUP length in ‘ millimeter III IV V VI VII VIII IX X XI XII XIII XIV 250-259 1 260-269 270-279 280-289 290-299 300-309 2 310-319 320-329 330—339 340-349 350-359 360-369 370-379 380-389 390-399 400-409 1 410-419 420-429 1 430-439 440-449 1** 1 450-459 460-469 1 470-479 1** 480-489 1** 490-499 1 1 F'N HI- I—‘l—‘U‘Ifl-bUJbH NNbNbNUJH 1.; HHWWUfi NWNI—‘H l—J l—‘l—‘bml-‘ONU'IUU bah-Nt-<fi(»+- 1.: I-‘l-‘I-‘U'IO‘QQQN F'H |._J f—l Average Total Length 296 317 311 323 322 333 339 346 398 424 O 490 Total Number of Fish 5 12 27 47 37 36 14 12 6 4 0 1 **Designates fast growing whitefish. APPENDIX B 54 July 11: 1957 (Slow growing fish designated by *) Catalogue Total Weight Number Length 1 372 19 2 351 14 3 394 18 4 369 16 5 383 17 6 352 14 7 370 15 8 360 15 9 .377 18 10 422 23 11 395 19 12 407 21 13 400 20 14 305 14 15 365 13 16* 342 12 17 336 12 18 341 12 19* 326 ll 20 344 11 21 315 10 22 310 8 23 310 8 24 306 8 25 322 10 26 322 8 27 301 8 28 315 8 29 329 9 30 290 7 31 319 9 32 333 ll 33 298 8 34 330 ll 35 316 9 36 301 8 37 303 9 38 309 8 39* 308 8 40 299 8 41 297 .8 42 296 8 43 308 8 55 July 11, 1957 Catalogue Total Weight Catalogue Total Weight Number Length Number Length 44 289 7 88 450 35 45 311 9 89 '450 32 46 284 7 90 434 25 47 320 9 91 417 21 48 449 28 92 537 55 49 397 20 93 504 40 50 428 25 94 482 35 51 397 21 95 450 32 52 450 26 96 465 32 53 470 35 97 400 22 54 448 28 98 433 29 55 440 24 99 407 22 56 471 29 100 522 47 57 405 23 101 475 36 58 412 23 102 449 32 59 408 21 103 458 29 60 420 23 104 390 22 61 414 21 105 449 25 62 433 24 106 441 28 63 426 25 107 435 26 64 422 25 108 425 34 65 414 23 109 433 26 66 430 24 110 433 27 67 400 22 111 434 25 68 415 23 112 461 38 69* 394 19 113 480 37 70 560 52 114 397 21 71 445 26 115 414 24 72 447 23 116 408 21 73 425 25 117 433 24 74 430 25 118 406 22 75 405 21 119 404 21 76 390 21 120 388 20 77 434 23 121 415 22 78 387 19 122 435 29 79 408 20 123 417 25 80 437 28 124 413 24 81 468 30 -125 399 24 82 463 35 126 475 38 83 396 19 127 440 31 84 423 26 128 435 28 85 497 42 129 416 23 86 460 38 130 443 32 87 520 46 131 412 24 56 July 11, 1957 Catalogue Total Weight Catalogue Total Weight Number Length Number Length 132 399 21 178 403 21 133 440 27 179 405 20 134 416 23 180 407 18 135 398 21 181 416 20 136 417 24 182 420 20 137 404 23 183 381 18 138 415 23 184 413 21 139 420 24 185 403 22 140 440 26 186 416 21 141 463 28 187 400 21 142 431 25 188 391 18 143 406 21 189 423 24 144 407 21 190 414 21 145 409 22 191 434 25 146 416 22 192 442 33 147 414 23 193 543 61 148 493 38 194 449 29 149 439 25 195 431 29 150 407 20 196 415 21 151 399 19 197 406 22 152 407 20 198 406 22 153 391 19 199 402 20 154 423 28 200 415 24 155 393 20 201 461 31 156 429 28 202 417 25 157 412 25 203 430 25 158 435 27 204 411 23 159 439 28 205 498 44 160 460 36 206 408 22 161 415 24 207 394 22 162 402 19 208 414 22 163 401 17 209 432 24 164 430 27 210 463 36 165 456 30 211 402 24 166 442 25 212 460 33 167 396 21 213 438 25 168 450 28 214 439 29 169 439 28 215 402 ' 22 170 408 24 216 403 20 171 402 211 217 471 35 172 406 20 218 388 19 173 406 20 219* 437 29 174 399 20 220 440 29 175 473 35 221 404 19 176 401 21 222 404 20 177 420 22 223 422 25 57 July 11, 1957 Catalogue Total Weight Catalogue Total Weight Number Length Number Length 224 397 19 263 456 32 225 391 18 264 443 27 226 482 36 265 413 22 227 439 26 266 445 29 228 440 28 267 413 22 229 438 27 268 418 23 230 384 21 269 453 31 231 428 26 270 447 30 432 409 22 471 447 28 233 425 27 272 442 24 234 440 25 273 417 23 235 421 23 274 417 23 236 394 19 275 433 22 237 416 24 276 465 23 238 422 24 . 277 440 32 239 413 24 278 415 25 240 425 24 279 474 37 241 400 19 280 436 24 242 398 21 281 428 24 243 431 25 282 431 24 244 393 19 283 435 27 245* 412 21 284 440 28 246 399 20 285 444 29 247 422 26 286 434 27 248 422 25 287 437 26 249 422 27 288 662 98 250 446 31 289 471 36 251 457 .31 290 479 35 252 452 30 291 477 36 253 460 30 292 436 27 254 456 30 293 425 25 255 430 27 294 467 30 256 460 38 295 446 28 257 431 27 296 437 26 258 442 20 297 435 27 259 419 19 298 445 28 260 429 21 299 448 26 261 424 22 300 485 35 262 434 23 58 May 23, 1958 Catalogue Total Weight Catalogue Total Weight Number Length Number Length 1 423 28 39 428 26 2 458 30 40 442 29 3 425 23 41 455 27 4 520 50 42 452 30 5 448 28 43 523 44 6 452 28 44 466 34 7 440 28 45 430 27 8 458 34 46 489 43 9 439 29 47 482 36 10 450 32 48 455 32 11 465 34 49 440 29 12 435 23 50 457 32 13 450 31 51 438 29 14 439 26 52 492 41 15 463 33 53 435 27 16 447 29 54 453 33 17 483 38 55 462 31 18 465 31 56 458 31 19 454 26 57 472 37 20 456 31 58 474 36 21 447 27 59 434 27 22 455 32 60 458 33 23 440 26 61 474 34 24 463 34 62 440 32 25 434 25 63 550 58 26 428 25 64 465 37 27 470 30 65 460 36 28 532 45 66 438 30 29 432 27 67 532 53 30 515 50 68 428 25 31 516 44 69 435 28 32 442 26 70 437 26 33 430 " 25 71 456 33 34 440 24 72 440 25 35 435 25 73 445 28 36 438 27 74 429 26 37 437 31 75 551 60 38 460 34 76 455 27 59 June 21 I 1961 (Slow growing fish designated by *) Catalogue Total Standard Weight Number Length Length 1 387 327 18 2 415 357 22 3 405 339 20 4 378 313 15 5 365 305 14 6 355 288 11 7 351 291 12 8 407 340 22 9 361 297 15 10 405 344 23 11 374 316 15 12 341 286 13 13 342 287 13 14 383 321 18 15 351 297 7 16 340 284 11 17 349 288 14 18 376 311 15 19 375 319 16 20 373 314 15 21 370 308 19 22 377 312 18 23 381 323 18 24 382 321 18 25 357 291 14 26 278 322 16 27* 310 --— 9 28 365 313 16 29 297 245 8 30 335 283 11 31 308 253 8 32 317 267 10 33 299 248 -- 34 308 251 8 35 299 243 7 36 350 291 12 37 466 400 32 38 428 356 27 39 455 369 29 60 June 21, 1961 Catalogue Total Standard Weight Number Length Length 40 456 378 31 41 456 370 35 42 434 358 27 43 455 382 35 44 437 366 25 45 474 398 37 46 475 400 35 47 450 377 31 48 428 360 26 49 470 401 34 50 440 370 27 51 425 354 24 52 457 385 29 53 491 407 36 54 449 375 31 55 464 389 33 56 467 390 32 57 434 362 25 58 420 354 28 59 453 378 28 60 462 385 32 61 464 394 36 62 506 430 46 63 462 388 33 64 489 410 33 65 433 358 29 66 435 364 27 67 455 380 36 68 550 464 47 69 430 362 26 70 469 392 36 71 428 356 , 28 72 433 364 ' 25 73 457 378 29 74 440 367 34 75 438 360 24 76 456 383 35 77 450 376 28 78 367 311 19 79 479 400 40 61 June 21, 1961 Catalogue Total Standard Weight Number Length Length 80 456 381 34 81 465 383 32 82 445 367 28 83 451 377 30 84 525 440 53 85 464 388 37 86 476 398 38 87 485 406 39 88 486 406 39 89 482 407 .39 90 511 433 45 91 426 358 24 92 426 360 26 93 485 , 404 33 94 ‘ 299 250 7 95 275 228 5 96 309 257 8 97 319 268 10 98* 352 288 14 99 315 265 9 100 300 251 8 101* 264 221 5 102 310 258 9 103 300 ‘ 249 8 104 321 262 10 105 311 258 8 106* 354 291 13 107 326 271 11 108 415 350 20 109 331 276 14 110* 370 306 16 111 341 282 13 62 July 19, 1961 (Slow growing fish desiganted by-*) Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 1 342 290 12 63 90 2 350 290 12 63 93 3 289 237 7 52 77 4 283 233 7 52 76 5 295 240 8 54 74 6 308 251 8 57 79 7 307 259 8 55 83 8 403 337 23 78‘ 106 9 399 336 23 72 105 10 416 348 24 74 110 11 422 352 25 74 110 12 460 388 33 -- --- 13 422 355 29 -- --- 14 310 255 8 53 .74 15 452 373 29 -- --— 16 510 421 41 83 115 17 460 377 29 77 99 18 457 384 38 -- --- 19 430 360 23 -- --- 20 430 364 24 -- --- 21 406 342 23 70 109 22 345 284 11 60 90 23 316 262 9 64 81 24 340 276 12 56 88 25 361 299 17 65 103 26A 331 275 10 .58 80 26B 268 307 15 71 95 27* 340 284 12 .61 91 29A 361 304 12 77 99 29B 403 331 22 79 104 30 410 347 25 68 112 31 383 324 16 68 102 32 416 355 22 70 107 33 407 334 22 70 109 34 418 347 22 74 105 35 415 348 24 74 111 36 425 357 24 73 112 37 405 340 22 66 110 63 Ju1y 19, 1961 VT fi Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 38 427 362 23 70 115 39 420 353 21 75 108 40 406 344 22 69 109 41 415 350 22 76 110 42 .465 384 32 -- --- 43 425 360 23 74 111 44 422 356 27 72 115 45 345 291 13 61 92 46 556 476 59 -- --- 47 522 440 51 -- --- 48 496 416 46 -- --— 49 463 386 33 -— --- 50 460 386 28 -- --- 51 410 338 22 70 109 52 420 354 ’ 24 75 113 53 418 350 22 75 110 54 336 283 12 60 86 55 425 360 24 75 120 56 444 370 27 -- --- 57 449 380 30 -- --- S8 408 478 22 74 112 59 312 258 9 58 80 60 425 356 25 76 117 61 470 392 32 . -- --- 62 448 374 28 -- --- 63 419 347 22 78 108 64 457 381 33 -- --- 65 500 422 45 -- --- 66 404 332 23' 69 115 67* 362 304 12 78 91 68 456 383 ~31 -- --- 69 420 346 23 75 116 70* 381 311 ,16 72 97 71‘ 417 341 23 77 95 72* 403 338 320 76 108 73 .392 325 18 70 103 74 421 357 24 78 ’ 108 75 ‘ 422 354 27 . 73. 1117' ,76 .425 - 357 24 71 116 77 410 338 23 73 '102 64 July 19, 1961 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 78 417 366 27 73 118 79 419 354 25 75 116 80 413 347 24 71 117 81 410 349 26 77 116 82 413 346 26 72 108 83 359 290 15 62 92 84 414 346 24 74 115 85 403 337 21 70 110 86 402 335 21 77 105 87 410 346 22 72 109 88 410 345 22 72 111 89 417 348 22 69 112 90 405 337 27 69 107 91 405 347 23 70 112 92 413 347 21 74 109 93 416 348 26 74 114 94 422 353 24 75 112 95 421 348 25 72 115 96 412 344 23 72 113 97 379 321 17 66 99 98 412 342 21 73 108 99 390 .327 21 71 109 100 408 342 21 69 109 101 428 364 24 75 105 102 419 347 .21 75 110 103 410 342 23 72 110 104 392 333 22 70 109 105 410 344 20 71 107 106 391 327 18 65 105 107 395 336 18 69 107 108 423 357 24 73 115 109 420 354 24 73 116 110 418 349 25 73 116 111 405 336 22 70 108 112 405 337 22 69 113 113 423 357 26 75 114 114 410 346 21 68 114 115 411 348 22 72 111 116 418 350 22 73 107 117 --- 390 31 74 129 65 July 19, 1961 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 118 --— 435 33 88 126 119 571 465 57 95 142 120 470 390 32 78 124 121 448 373 28 78 121 122 447 373 27 76 116 1A 415 348 22 -- --- 2A 394 329 -— 76 110 3A 418 349 29 73 116 4A 325 263 9 58 78 5A 311 260 9 53 .77 6A 322 274 10 61 85 7A 359 301 14 62 91 8A 415 348 23 74 104 9A 416 342 v 22 74 103 10A 408 338 25 70 113 11A 415 349 25 72 111 12A 422 348 -- 74 112 13A 406 343 24 71 110 14A 348 290 13 62 89 15A 402 336 26 67 109 16A 421 353 24 70 109 17A 416 350 26 70 108 18A 415 348 26 74 113 19A 402 338 20 67 108 20A 411 346 23 69 110 21A 400 338 23 69 109 22A 405 340 21 71 105 23A 420 350 23 73 114 24A 405 342 29 74 116 25A 412 348 29 74 110 26A 416 342 26 71 110 27A 420 350 21 69 —-- 28A 418 346 24 74 115 29A‘ 355 298 15 63 91 30A 348 281 10 67 89 31A 349 287 12 59 84 32A 307 257 10 54 82 33A 417 349 24 71 104 34A 334 277 12 73 91 35A 425 361 23 76 109 66 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 36A 410 343 23 75 110 37A 292 240 8 52 66 38A 305 252 8 51 78 39A 410 347 23 73 114 40A 413 349 22 66 106 41A 398 332 23 -- -—- 42A 417 350 24 -- --- 43A 286 236 7 —- --- 44A 295 242 8 -- --- 45A 411 342 21 —- -—- 46A 423 354 25 -- —-- 47A 417 352 22 -- --- 49A 327 271 11 -- --- 50A 420 352 22 -- -—- 51A 422 355 24 -- --— 52A 294 244 7 -- --- 53A 321 269 10 -- --- 54A 416 347 21 -- --- 55A* 322 257 25 -- --- 56A 400 334 21 -- --- 57A 363 297 13 -- -—- 58A 318 262 9 -- --- 59A 348 287 13 -- --- 60A 329 275 12 -- —-- 61A 407 349 27 73 114 67 October 26, 1961 (Fast growing fish desiganted by **) Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 1 342 287 12 66 85 2 324 268 8 63 78 3 356 292 9 67 82 4 313 256 9 57 75 5 357 300 14 64 93 6 344 282 11 62 87 7 321 266 10 61 80 8 357 295 11 65 84 9 339 279 10 67 78 10 343 288 ll 61 88 11 3 348 287 11 66 86 12 330 273 g 10 162 75 13 333 277 10 62 84 14 320 265 8 60 75 15 351 288- 11 68 80 16 346 281 10 62 83 17 314 257 7 61 .70 18 315 262 8 64 75 19 300 247 7 \ 54 72 20 388 276 10 62 79 21 322 270 9 60 80 22 365 305 12 64 91 23 323 267 9 59 84 24 320 264 8 '58 82 25 309 255 8 58 75 26 323 266 8 62 80 27 329 268 9 61 79 28 306 252 7 51 74 29 325 271 9 59 75 30 323 269 9 60 82 31 347 288 10 63 84 32 338 280 10 63 81 33 299 250 7 55 75 34 352 290 11 63 88 35 333 278 10 64 77 36 309 255 8 56 77 37 330 274 9 61 79 38 326 272 9 59 81 68 October 26, 1961 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 39 318 265 8 62 81 40 335 277 9 60 80 41 298 245 7 56 7O 42 305 252 7 57 71 43 305 250 8- 55 73 44** 475 400 35 80 129 45** 445 372 27 75 115 46 469 388 31 85 123 47** 481 405 34 80 121 48 498 417 41 91 132 49 400 328 20 74 106 50 449 375 29 80 116 51 490 407 34 88 120 52 317 252 ~ 8 54 74 53 395 327 17 70 99 54 377 312 15 69 95 55 362 298 12 66 97 56 358 292 12 64 85 57 328 272 10 62 80 58 341 281 10 66 85 59 320 264 9 60 81 60 342 284 11 64 86 61 329 270 9 7O 80 62 295 240 7 55 75 63 340 282 11 62 88 64 368 307 13 68 91 65 375 307 13 68 91 66 319 265 9 6O 79 67 306 255 8 57 73 68 367 303 14 69 87 69 350 285 12 67 82 70 374 311 14 66 88 71 314 263 8 55 72 72 326 268 9 64 79 73 393 327 17 74 98 74 423 349 23 83 106 75 345 287 11 63 91 76 316 258 9 6O 76 77 318 263 9 67 77 69 October 26, 1961 J _— Catalogue Total Standard weight Head Dorsal- Number Length Length Length Pectoral 78 353 293 12 63 92 79 281 231 7 54 70 80 366 300 13 66 90 81 323 269 9 58 77 82 331 278 11 ‘ 61 80 83 331 273 9 61 82 84 320 264 9 56 81 85 318 252 8 62 76 86 322 265 9 59 82 87 308 252 8 59 77 88 335 280 9 61 83 89 330 271 10 65 75 90 326 268 9 58 78 91 365 303 . 14 66 91 92 337 .278 11 64 85 93 331 277 11 63 85 94 328 279 9 62 80 95 318 265 8 58 76 96 355 294 12 63 93 97 325 270 10 59 82 98- 352 290 12 66 90 99 320 269 9 61 83 100 315 260 9 58 79 101 325 267 9 58 79 102 383 315 16 77 92 103 330 273 10 62 83 104 342 281 9 60 80 105 324 269 8 57 78 106 338 278 11 67‘ 83 107 ’ 328 270 9 59 76 108 354 289 12 68 75 109 345 296 9 65 84 110 308 252 7 57 76 111 317 264 10 62 80 112 310 258 8 59 78 113 .306 255 8 62 72 114 301 240 7 59 70 115 297 245 8 54 72 116 316 263 8 59 74 117 323 268 10 63 84 70 October 26, 1961 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length 'Pectoral 118 309 257 8 62 77 119 305 252 7 53 77 120 322 265 8 58 81 121 328 273 9 59 80 122 313 255 8 56 77 123 319 266 9 57 74 124 310 258 8 57 78 125 288 238 6 54 70 126 305 250 8 59 77 127 315 283 9 57 77 128 310 258 8 6O 71 129 318 265 9 58 78 130 318 258 8 57 75 131 331 278 - 10' 58 80 132 351 284 10 70 82 133 338 278 12 63 89' 134 390 ~320 16 75 91 135 315 262 8 58 79 136 360 297 11 65 86 137 299 253 7 54 74 138 323 273 10 58 84 139 322 266 8 57 80 140 " 338 280 9 60 81 141 321 269 8 58 75 142 300 248 7 53 74 143 322 268 9 59 79 144 334 278 9 61 ‘79 145 351 291 11 67 88 146 334 273 9 61 85 147 338 284 10 62 84 148 307 257 7 55 76‘ 149 337 277 9 59 82 150 315 262 8 56 78 151 299 248 7 57 72 152 333 277 9 64 80 153 306 255 8 55 76 154 354 294 12 64 84 155 315 262 7 59 74 156 310 257 7 58 71 157 316 258 8 57 78 71 October 26,:1961 Catalogue Total Standard Weight Head Dorsal- Number Length Length Length Pectoral 158 329 278 9 60 83 159 285 235 6 53 67 160 320 267 10 57 85 161 329 270 10 62 82 162 316 264 10 57 80 163 347 295 12 .65 90 164 304 258 8 .57 79 165 330 277 8 63 78 166 323 268 10 59 83 167 322 266 8 60 83 168 252 --- 8 55 78 169 295 --— 7 66 77 170 323 270 8 61 79 171 348 287 ' 11 68 85 172 316 260 7 58 75 173 314 262 7 57 75 174 318 265 8 6O 77 175 332 277 8 65 76 176 308 348 6 62 73 177 320 268 '7 60 78 178 304 251 7 58 75 179 312 261 7 59 771 180 321 267 7- 58 77 181 277 230 5 54 67 182 347 290 12 64 87 183 341 287 10 60 85 184 312 257 8 57 79 185 323 268 8 60 78 186 340 280 10 61 83 187 310 261 7 57 75 188 300 252 7 56 74 189 286 240 6 54 72 190 292 244 7 57 70 191 355 301 12 65 88 192 310 258 6 57 78 193 324 274 9 59 82 194 293 242 5 54 72 195 317 262 7 59 79 196 310 256 6 61 70 197 282 217 5 52 70 198 298 248 6 53 71 199 287 238 .7 ,54 69 200 289 240 6 56 65 201 315 258 8 57 76 , .- mi ' A“, r“ .0 JV” ,R‘LY, A13 USE C" ' 339* “h "‘111111111111Es