Discriminating Populations of the Eastern King Prawn, Penaeus plebejus, From Different Estuaries Using ICP-MS Trace Element Analysis

Abstract

ICP-MS is being used to determine if prawns, like some species of fish, possess an "environmental imprint" attained in their juvenile nursery habitats. Such an imprint could act as a naturally occurring tag and provide useful information on nursery grounds, migration patterns, and stock structure. Samples of juvenile eastern king prawns, Penaeus plebejus, from four different estuarine nursery areas several hundreds of kilometers apart were distinguished from one another using combinations of the concentration of elements in their body tissues. Four different body tissues were used: eyes, hepatopancreas, abdominal muscle, and exoskeleton. Canonical-variate (discriminant) analyses showed that each of the four body tissues could be used to correctly classify the samples with high (100%) predictability. The results although helpful, should be treated with caution as they only provide a static and narrow representation of the prawns' elemental profiles in space and time. Further experiments are in progress to determine if the prawns retain these differences through time in the wild and in the laboratory.