Food Habits of the Sea Bream, Archosargus Rhomboidalis (Linnaeus), and Comparative Growth on Plant and Animal Food

Food habits and utilization of plant and animal food by an omnivorous, tropical sparid fish, the sea bream (Archosargus rhomboidalis) were studied. Stomach analysis of fish from Biscayne Bay, Florida, showed changes in the proportion of various food items as the fish grew: 4.1–8.0 cm fork length sea bream ate mostly amphipods; larger fish (8.0–10.0 cm) ate filamentous algae; ingestion of coarser algae and vascular plants increased as fish grew. Molluscs formed a significant portion of the diet of fish greater than 20.0 cm. Sea bream fed mostly during daylight.

Juvenile sea bream (8.6–13.0 cm FL) were fed shrimp, or one of two filamentous algae, Enteromorpha flexuosa and Polysiphonia subtilissima, at 25°C, for 18 days, to compare their growth on these foods. The fish had a mean weight gain of 7.87% dry weight when fed shrimp; fish fed on Enteromorpha and Polysiphonia experienced losses similar to those of starved controls (−9.48, −24.64, and −21.60% respectively). Sea bream apparently need animal as well as plant food to survive and grow.