FEEDING-HABITS OF BONEFISH, ALBULA-VULPES, FROM THE WATERS OF THE FLORIDA-KEYS

We examined stomach contents of 385 bonefish that ranged in length fro m 228 to 702 mm FL. Relatively few prey species made up most of the di et by weight-xanthid crabs (29.9%), gulf toadfish, Opsanus beta (17.2% ), portunid crabs (10.9%), alpheid shrimp (9.2%), and penaeid shrimp ( 7.7%) together made up 74.9%. A variety of gastropods (17 families and 24 species) and bivalves (9 families and 16 species) were eaten, but gastropods made up only 2.7% of the diet by weight and bivalves made u p only 2.5%. Polychaetes, represented by at least seven families, were important in the diet numerically (37.1%) but made up little of the d iet by weight (1.4%). Cluster analysis and ordination of stomach conte nts permitted bonefish to be grouped according to length. Large bonefi sh (>439 mm FL) ate more xanthid crabs, alpheid shrimp, Callinectes sp p., and O. beta than did small bonefish; penaeid shrimp were more impo rtant in the diet of small bonefish (<440 mm FL). The stomach contents of bonefish caught in Florida Bay were significantly different from t hose of bonefish caught on the ocean (Florida Straits) side of the Flo rida Keys, but the differences were slight and the same prey taxa domi nated the diet in both areas. Xanthid crabs, alpheid shrimp, O. beta, penaeid shrimp, and Callinectes spp. together made up over 50% of the dissimilarity in diet of bonefish between the two areas. Some seasonal effects on diet were found, but variable sample sizes among seasons i n the respective sampling areas made it difficult to detect seasonal t rends. Bonefish fed selectively on some prey groups, but other common prey groups were not selected and were less common in stomachs than in the prey environment. The suite of epibenthic crustaceans and fishes found in bonefish stomachs was significantly different from that avail able as prey in the environment. Our results suggest that teleosts, ma inly O. beta, are more important in the diet of bonefish than reported in previous studies.