Preferred Temperatures of Yearling Lake Trout of the Marquette and Manitoba Strains

摘要

The preferred temperatures of yearling lake trout (Salvelinus namaycush) of the Marquette and Manitoba strains were determined by using temporal thermal-gradient shuttleboxes. Lake trout of both strains were reared from the fry stage at the Great Lakes Fishery Laboratory under similar conditions (photoperiod, temperature, and ration). The mean preferred temperature of fish of the Marquette (10.2C) and Manitoba (9.2C) strains did not differ significantly and the preferred temperature ranges of the two strains were similar. Temperature preference of yearlings of the two strains thus does not appear to differ; the post-planting depth and temperature distribution of the two strains in Lake Ontario is most likely the result of a complex interaction between many environmental factors (temperature, depth, food availability, predation, behavior, light intensity, etc.).