On a collection of fish and prawns from the East Alligator estuary, Kakadu National Park, Australia

Abstract

52 species of fish and 16 species of prawns were collected from estuarine and inshore waters of the East Alligator River and Murgenella Creek in Kakadu National Park by beam trawl between September 1978 and May 1979. Sciaenids dominated the fish fauna, with Johnius novaeguineae being the most abundant species, followed by the gobioidid Brachyamblyopus rubristriatus, another sciaenid Johnius weberi, and the polynemid Polynemus verekeri. The prawns were dominated by a sergestid, Acetes sp., and a penaeid, Atypopenaeus formosus. Four species of fish are new records for Australia: Ilisha megalopetra, Datniodes quadrifasciatus, Johnius macropterus and Johnius novaeguinae. Four species do not appear to have been described: Leiognathus sp. 1; two sciaenids and a goby. The fish in this region are estuarine and inshore species typical of tropical Indo-Pacific waters with high turbidity and fluctuating salinities and, despite the restrictions of beam trawl sampling, include a number of species that occur in inshore waters of the Gulf of Carpentaria as well as tidal swamp areas near Darwin.