Growth and migration of tagged eastern Australian king prawns, Penaeus plebejus Hess

Abstract

Growth rates and migration of P. plebejus were investigated by a series of tagging experiments. Growth records of 157 recaptured, streamer-tagged prawns from 2450 releases were analysed for estimates of von Bertalanffy growth parameters by Fabens method. The size-age relationship differed between sexes with males attaining only 75% of the maximum size of female prawns. There was no appreciable size-related mortality of tagged individuals. Recaptured tagged prawns confirmed the previously determined northerly movement and showed little movement toward deeper water off New South Wales. Once past the easternmost point of the continent dispersal into a range of depths occurred. There was no apparent relationship between rates of movement and size, suggesting that fluctuations in the intensity of the East Australian Current were responsible for variations in these rates. Based on the results of this and other tagging studies, a two-substock hypothesis, defined by the origins of the bulk of recruits, is postulated.