REPRODUCTIVE STRATEGY IN YELLOW PERCH (PERCA-FLAVESCENS) - EFFECTS OF DIET ONTOGENY, MORTALITY, AND SURVIVAL COSTS

Under the diets zooplankton only; zooplankton and benthos; zooplankton, benthos, and fish, optimal age at first reproduction decreased as the decrease in mortality caused by reproduction increased. When adult yellow perch fed only on zooplankton, adult survival rate has little effect on optimal age at first reproduction. When fish and benthos are utilized, the optimal age at first reproduction varies strongly with adult survival. Growth rates were affected by both age at maturity and diet ontogeny, with diet ontogeny having a much greater effect. Maximal adult size was affected by reproductive strategy in each case, with larger terminal sizes obtained when maturity was delayed. Increases in size with delayed maturity were greatest when zooplankton, benthos, and fish were available as prey items. -from Authors