ENZYME VARIATION IN JACKASS MORWONG, NEMADACTYLUS-MACROPTERUS (SCHNEIDER, 1801) (TELEOSTEI, CHEILODACTYLIDAE), FROM AUSTRALIAN AND NEW-ZEALAND WATERS

Nemadactylus macropterus was sampled from eight localities around sout hern Australia, ranging from Western Australia to New South Wales, and from one area off the western coast of New Zealand. Thirty-three enzy me loci were analysed by gel electrophoresis. Average heterozygosity p er locus per sample was 10.1 %, ranging from 8.4% to 11.1% per sample. Although no significant differentiation was observed among the Austra lian samples, there was significant differentiation between the Austra lian and New Zealand samples. This was primarily attributable to varia tion at the sAAT-1 locus, where the common allele had a frequency of around 0.80 in Australian samples and around 0.94 in the New Zealand s ample (P<0.001). Across all 33 loci, 0.47% of the total genetic variat ion in Australian and New Zealand samples was due to differentiation b etween these two areas. This is significantly greater (P=0.001) than t he value of 0.17% that could be ascribed to sampling error alone. Two loci (ADH and GPI-1*) that had previously been reported as monomorphi c in New Zealand specimens were found to be polymorphic in the New Zea land samples analysed in this study, and allele frequencies at these l oci were indistinguishable from Australian samples.