Feeding rate of young-of-the-year ruffe on eggs of lake whitefish

We measured the feeding rate of individual (0.6-12.2 g) young-of-the-year ruffe (Gymnocephalus cernuus) on the live eggs of lake whitefish (Coregonus clupeaformis) at 3, 5, and 9 degrees C in the laboratory. These temperatures were selected because they covered the range of lake temperatures over which eggs of most Great Lakes coregonines would be most vulnerable to predation by ruffe. Ruffe readily consumed lake whitefish eggs, and regression analysis showed consumption increased with ruffe size and water temperature. Mean daily egg consumption as a percent of mean ruffe body weight was 0.25% at 3 degrees C, 0.59% at 5 degrees C, and 1.00% at 9 degrees C.