Survival of larval milkfish, Chanos chanos, during changeover from endogenous to exogenous energy sources

Abstract

Survival of laboratory-reared larvae of milkfish, Chanos chanos , during transition from the prelarval to postlarval stages was examined in relation to the changeover of energy sources. The prelarval and early postlarval stages of the fish can be divided into 5 phases; 1) rapid growth corresponding to rapid yolk less rapid yolk resorption; 3) stagnant growth with rapid yolk resorption, yolk being still the only nutrient for the larvae; 4) stagnant growth based on both yolk and exogenous food, from the onset of feeding to the complete exhaustion of yolk; and 5) rapid growth based solely on exogenous food. The survival rate decreased when the larvae depended solely on yolk, then leveled off when they had both endogenous and exogenous energy sources, and again declined when they came to depend totally on exogenous food. Feeding during the period from the onset of feeding to complete yolk resorption seems important for the successful survival of milk-fish larvae thereafter.