Growth, Development, and Feeding Success of Atlantic Cod Larvae Gadus morhua Related to Egg Size

Abstract

Abstract The size of Atlantic cod eggs declines during the spawning season, and the potential effects of this on larval development were studied. Eggs from 12 females were artificially fertilized and incubated in separate aquaria. Egg diameter was correlated significantly (P < 0.05) with egg dry weight. The standard length of unfed larvae continued to increase a few days beyond yolk exhaustion, whereas the increase in muscle tissue (myotome height) reached its maximum at the time of yolk exhaustion. Egg dry weight was significantly correlated with larva dry weight, standard length, myotome height, and the size of the mouth gape. The ability of larvae to capture artemia nauplii was related to the size of their mouth gape, itself a function of larval size. Atlantic cod larvae from large eggs may survive the shift to exogenous feeding better than those from small eggs. Late-spawned Atlantic cod larvae may have a lower survival potential than those spawned earlier in the season.