Food Consumption and Bioenergetics of Young-of-the-Year Walleye (Stizostedion vitreum vitreum): Model Predictions and Population Density Effects

Abstract

I compared in situ growth and food consumption estimates of young-of-the-year walleye (Stizostedion vitreum vitreum) reared at three different densities in outdoor ponds with predictions of a bioenergetic model for walleye (KitcheH et al. 1977. Res. Board Can. j. Fish. 34: 1922–1935), and used the model to determine whether fish population density affects growth efficiency or metabolism. Maximal walleye growth rate was adequately predicted by model simulations. Consumption estimates were 40% lower than predicted, but predictions were improved when the respiration equation of Minton and McLean (1982. Can. J. Fish. Aquat. Sci. 39: 1396–1403) was substituted in the model. There was no evidence that juvenile walleye have higher consumption or respiration rates than those predicted by allometric models based on larger fish. Walleye in low-density ponds had a higher growth efficiency and active metabolic rate than those reared at lower densities, but the difference was not statistically significant.