Diets of trawled predatory fish of the Gulf of Carpentaria, Australia, with particular reference to predation on prawns

Abstract

The diets of 79 predatory fish species from 128 trawling stations in the Gulf of Carpentaria are described. Twenty-three of the 40 most abundant predatory species were major piscivores (more than 50% by dry weight of their diets consisted of teleosts). These fish ate mainly Pleuronectiformes, Leiognathidae and Anguilliformes. For 14 of the 17 minor piscivore species (less than 50% by dry weight of their diets consisted of teleosts), members of the Crustacea (Brachyura, Penaeidae, Stomatopoda and other Crustacea) were the main dietary items. Members of the Penaeidae were the second most important crustacean component in the combined diets after Brachyura, but they represented a relatively small fraction of the diet of all 27 prawn-eating fish species. Most of the penaeid prey consisted of small, non-commercial Metapenaeopsis spp. and Trachypenaeus spp. The diets of four species -Arius thalassinus, Carangoides rnalabaricus, Lutjanus rnalabaricus and Nernipterus furcosus- showed evidence of seasonal differences.