EFFECTS OF EGG COMPOSITION AND PREY DENSITY ON THE LARVAL GROWTH AND SURVIVAL OF LAKE WHITEFISH (COREGONUS-CLUPEAFORMIS MITCHILL)

Eggs were collected from two stocks of lake whitefish, Coregonus clupeaformis, in Lakes Michigan and Huron to assess the effect of egg composition and prey density on larval growth and survival. Egg composition parameters including wet weight (mg egg−1), dry weight (mg egg−1), percent water, total caloric content (cal egg−1), caloric density (cal egg−1), percent lipid content, and total lipidcontent (mg egg−1) were measured. Fish hatched from six parental females in each stock were fed one of four rations (0, 18, 24, 50 brine shrimp larva−1 day−1) after yolk sac absorption. Length at hatch, endogenous growth, exogenous growth, and survival were measured during a 42‐day laboratory experiment. Length at hatch of larvae was positively related to egg caloric content (r2=0.780). Endogenous growth for lake whitefish larvae was positively related to percent lipid content (r2=0.896) and total egg lipid content (r2=0.876) of parental females. Exogenous growth and survival of larval lake whitefish was positively related to prey availability. Larval fish growth was accurately modelled (r2=0.973) as a function of prey abundance using a threshold‐corrected hyperbolic equation. These results indicate that both egg composition and prey availability have the potential to influence the growth and survival dynamics of larval lake whitefish significantly. Copyright © 1992, Wiley Blackwell. All rights reserved