Enzyme variation in south-eastern Australian samples of the blue-eye or deepsea trevalla, Hyperoglyphe antarctica Carmichael 1818 (Teleostei: Stromateoidei)

Abstract

Six samples (n =67 to 154) of blue-eye or deepsea trevalla were collected from south-eastern Australia (seamounts off New South Wales, a seamount south-east of Tasmania called the Cascade Plateau, off the east, south and west coasts of Tasmania, and off the coast of South Australia). All fish were analysed by starch or cellulose acetate electrophoresis for the products of seven polymorphic loci (defined in this study as those with an average heterozygosity greater than 0.06); a minimum of 24 fish per area were also analysed for 29 other less variable loci. The average heterozygosity per locus was 5.3%. Polymorphic loci showed no significant deviations from Hardy-Weinberg equilibrium. The coefficient of genetic subpopulation differentiation, G_ST, was 0.38%. Bootstrapping procedures showed that this low value could be attributed to sampling error alone. Contingency Χ² analysis similarly failed to reveal any significant inter-sample differentiation for any locus. The results indicate that gene flow is sufficient to prevent any genetic differentiation among the sampled localities. During the course of the study a second trevalla species, Schedophilus labyrinthicus, was identified in the New South Wales component of the fishery.