LAKE TROUT BREEDING HABITS 



75 



spawned early. In all other lakes studied, the 

 lake trout spawned in shallow water and usually 

 later. Increased cloudiness in July, August, and 

 September, and low temperatures in September, 

 advanced the date of spawning in Raquctte 

 Lake. Shallower lakes had earlier spawning 

 dates. At the time of spawning, water tempera- 

 ture varied from 58° to 37° F., but in Raquette 

 and Otsego Lakes it was observed that spawning 

 times approximated the turn-over times of the 

 lakes. Generally, the spawning period was about 

 20 days, but it varied from 10 to 40 days and was 

 fairly consistent from year to year in any one lake. 



Spawning, whether in shallow or deep water, 

 took place on gravel or rubble bottom that had 

 crevices into which the eggs could roll. No nest 

 or redd was built. No evidence of spring water 

 was observed near any spawning area. 



In the spawning act, which usually occurred 

 during the evening, from 2 to 10 lake trout par- 

 ticipated. Each attempt at spawning lasted 

 only a few seconds; the act was repeated many 

 times. 



Approximately 1 month after spawning, a 

 sample of eggs recovered from the crevices in the 

 rocks of Otsego Lake was found to be 79 percent 

 alive. No measurement of the effects of preda- 

 tion on eggs was possible, but it was estimated 

 that only eggs that failed to roll into crevices 

 between the stones could be eaten by predators. 



In Otsego Lake in 1941 the eggs hatched about 

 April 15 and the fry left the spawning area about 

 May 22. In the deep water of Seneca Lake 

 where the lake trout had spawTied in early October 

 a single advanced fry was taken April 2, 1940. 

 Its development indicated that hatching occurred 

 in late January. 



Extensive operation of a small beam trawl, set 

 hnes, and minnow traps in Otsego, Keuka, and 

 Seneca Lakes failed to produce any lake trout 

 between advanced fry stage and a length of about 

 6 inches. Twelve specimens between 6 and 10 

 inches long that were captured in gill nets in Keuka 

 Lake were found to be 1- and 2-year-olds and to be 

 feeding mostly on Mysis relicta. 



ACKNOWLEDGM ENTS 



Deep appreciation is expressed to the following 

 people whose assistance made this work possible: 

 Dr. A. H. Wright, professor of zoology, Cornell 



University, Ithaca, N. Y., gave much encourage- 

 ment and made funds available; Peter I. Tack, 

 A. H. Underbill, and William M. La%vrence, 

 graduate students, and Philhp Strong, fish hatch- 

 ery foreman, provided a large amount of help in 

 the netting operations and the aquatic photog- 

 raphy. 



Members of the New York State Conservation 

 Department were most cooperative and generous 

 with their time and equipment. Among those to 

 whom I am particularly indebted are S. M. 

 Cowden, supervisor of fish culture; A. P. Miller, 

 district supervisor of fish culture; Dr. Emmehne 

 Moore and Dr. W. C. Senning, aquatic biologists; 

 Charles Deuell, David Haskell, K. B. Nichols, 

 and L. D. Winslow, fish hatchery foremen; and 

 L. D. Tompkins, game protector. 



I am further indebted to V. S. L. Pate and 

 Minter J. Westfall, Jr., for identification of aquatic 

 insects from Otsego Lake, and to J. R. Westman, 

 for scale samples and data on the lake trout of 

 Lake Simcoe, Ontario. 



LITERATURE CITED 



Atkinson, N. J. 



1931. The destruction of grey trout eggs by suckers and 

 bullheads. Trans. Amer. Fisheries Soc, vol. 61, pp. 

 183-188. 

 BissoNETTE, T. H., and J. Wendell Burger. 



1940. Experimental modification of the sexual cycle of 

 fish. Abstracts of papers presented at the North- 

 eastern Fish Culturists' Meeting, p. 12. 

 Cook, W. A. 



1929. A brief summary of the work of the Bureau of 

 Fisheries in the Lake Superior region. Trans. Amer. 

 Fisheries Soc, vol. 59, pp. 56-62. 

 Dymond, John Rich.\rd80N. 



1926. The fishes of Lake Nipigon. University of 

 Toronto Studies, Publications Ontario Fisheries Re- 

 .search Laboratory, No. 27, pp. 3-108. 

 Embody, George C. 



1934. Relation of temperature to the incubation periods 

 of eggs of four species of trout. Trans. Amer. Fish- 

 eries Soc, vol. 64, pp. 281-292. 

 EwiNG, Mavrice, a. Vine, and J. L. Worzel. 



1946. Photography of the ocean bottom. Jour. Optical 

 Soc. America, vol. 36, No. 6, June 1946, pp. 307-321. 

 Fry, F. E. J. 



1939. A comparative study of lake trout fisheries in 

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 Biol. Ser., No. 46: Publications of the Ontario Fish- 

 eries Research Laboratory, No. 58, pp. 7-69. 

 Fry, F. E. J., and W. A. Kennedy. 



1937. Report on the 1936 lake trout investigation, 

 Lake Opeongo, Ontario. Univ. of Toronto Studies, 



