Geographical distribution, growth and breeding miagration of the eastern Australian king prawn Penaeus plebejus Hess

Abstract

P. plebejus is commonly caught along the east coast of Australia between Bundaberg (25ºS.) and Lakes Entrance (38ºS.) and a few specimens have been recorded from Lord Howe Island and Tasmania. The results of tagging studies conducted to determine the relationship between juvenile (estuarine) stocks and adults at sea suggest that maturing prawns migrate along the coast to breed in warmer oceanic waters north of their estuarine habitat. The stocks from different estuaries mix at sea and appear to form a single large adult population in south-east Australia. It is postulated that the larvae are carried south from the spawning area by the East Australian Current system, occasionally as far south as Tasmania or east to Lord Howe Island (but not to New Zealand). The longest migration was 930 km (in 260 days) which is a record for an adult crustacean. The highest growth rate observed was a carapace length increment of 19½ mm (from 20½ to 40 mm) in 4 months.