Diet and feeding behaviour of juvenile and adult banana prawns Penaeus merguiensis in the Gulf of Carpentaria, Australia

Abstract

The diet of Penaeus mergulensis de Man was studied by examining the contents of the foreguts of 432 juven~les collected from estuarine and 467 adults from offshore habitats in the Gulf of Carpentaria between February 1985 and November 1989. The juveniles in the estuary had fed mainly at night and on rising or near-high tides; the largest amount of food was found in prawns collected 2 h after high tide. Crustaceans, bivalves, gastropods and polychaetes were the most common food items in the guts of both juveniles and adults. Copepods and other crustaceans were significantly more common in the diet of juvenile prawns caught at night. Foraminiferans, nematodes and algae were found less frequently as the size of the prawns increased. Comparative analysis of foregut contents showed no difference between schooling and non-schooling adult P. merguiensjs. The study shows that tidal stage, daylight, and the size of P. merguienes affect the compos~tion of the diet.