The mouth and gut develop the day after hatching. The larvae first live on their yolk sac and commence exogenous feeding on zooplankton at 45 to 50 hours after hatching (Kohno et al., 1986).
L. calcarifer is an opportunistic predator with an ontogenetic shift in the diet. Fish less than 40 mm feed almost exclusively on microcrustacea. With increasing fish size, this food type is progressively replaced by macrocrustacea, other invertebrates and fish (Davis, 1985) (see Figure 3).
Kungvankij et al. (1985) found that the stomach content of fish greater than 200 mm consisted of 70 percent crustaceans (such as shrimp and small crab) and 30 percent fish, while Davis (1985) observed that fish above 300 mm feed almost exclusively on fish, reaching 80 percent of the diet in the largest fish.
L. calcarifer is a suction feeder and prey is swallowed whole. There is a positive correlation between predator and prey length - the latter can reach 60 percent of predator length (Davis, 1985). Cannibalism is a common occurrence and hence it is necessary to grade the fish on a regular basis.
