Enzyme variation in jackass morwong, Nemadactylus macropterus (Schneider, 1801) (Teleostei: Cheilodactylidae), from Australian and New Zealand waters

Abstract

Nemadactylus macropterus was sampled from eight localities around southern Australia, ranging from Western Australia to New South Wales, and from one area off the western coast of New Zealand. Thirty-three enzyme loci were analysed by gel electrophoresis. Average heterozygosity per locus per sample was 10.1 %, ranging from 8.4% to 11.I% per sample. Although no significant differentiation was observed among the Australian samples, there was significant differentiation between the Australian and New Zealand samples. This was primarily attributable to variation at the sAAT-I * locus, where the common allele had a frequency of around 0.80 in Australian samples and around 0.94 in the New Zealand sample (P<0.001). Across all 33 loci, 0.47% of the total genetic variation in Australian and New Zealand samples was due to differentiation between these two areas. This is significantly greater (P=0.001) than the value of 0.17% that could be ascribed to sampling error alone. Two loci (ADH* and GPI-I *) that had previously been reported as monomorphic in New Zealand specimens were found to be polymorphic in the New Zealand samples analysed in this study, and allele frequencies at these loci were indistinguishable from Australian samples.