Genetic variation and population subdivison in the greentail prawn Metapenaeus bennettae (Racek & Dall)

Abstract

The genetic structure of M. bennettae populations from six locations on the east coast of Australia was investigated using starch-gel electrophoresis. Eight polymorphic loci (fumarate hydratase, glucose- 6-phosphate isomerase, malate dehydrogenase-1 and -2, mannose-6-phosphate isomerase, octanol dehydrogenase, phosphogluconate dehydrogenase and phosphoglucomutase) were examined. All loci over the six sites were in Hardy-Weinberg equilibrium. Although low levels of variation typical of penaeid prawns were found, the contingency Χ² analysis of allele frequencies over all locations revealed considerable genetic heterogeneity. However, pairwise comparisons of adjacent locations showed that most of this genetic heterogeneity was largely attributable to the Moreton Bay-Lake Macquarie comparison. These two locations are the most widely separated adjacent sample sites. Replicate samples from 1982 and 1983 revealed consistency in allele frequencies at Moreton Bay and at Lake Macquarie. These results confirm previously reported genetic heterogeneity between Queensland and New South Wales populations of M. bennettae, but they do not support the report that nearby populations in both Queensland and New South Wales are also heterogeneous.