An allozyme investigation of the stock structure of arrow squid Nototodarus gouldi (Cephalopoda: Ommastrephidae) from Australia

Allozyme electrophoresis was used to examine the stock structure of arrow squid Nototodarus gouldi (McCoy 1888) from Australia. Samples collected from six localities around southern Australia, separated by distances of between 700 and 4300km, were examined for allozyme variation at 48 loci. The data revealed no evidence of more than a single species among the 203 squid examined. Nine polymorphic loci were detected, although only three were sufficiently variable to provide real insight into the population structure of arrow squid. There were no significant deviations from Hardy-Weinberg expectations for any locus, population, or for the metapopulation. Pairwise comparisons of allele frequencies revealed minor evidence of stock structure, with the Iluka (north New South Wales) sample set displaying significant allelic differences from the Tasmanian sample set at Acyc and from the Ulladulla (south New South Wales) sample set at Sordh. F-statistics also provided weak support that the Australian metapopulation is not panmictic. Further studies are needed to delineate the degree of stock segregation within the Australian/New Zealand region in order to successfully manage the arrow squid fishery in these waters. © 2004 Published by Elsevier Ltd on behalf of International Council for the Exploration of the Sea.