Biochemical genetic evidence supporting the taxonomic separation of Loligo gahi from the Genus Loligo

Fifteen specimens of Loligo gahi caught within the Falkland Islands Interim Conservation and Management Zone during March 1988 were subject to genetic analysis using horizontal starch gel electrophoresis. Comparison of allele frequencies at 22 clearly resolving putative enzyme loci showed these animals to exhibit a degree of genetic differentiation from samples of Loligo forbesi and Loligo vulgaris vulgaris (I = 0.19 and 0.22 respectively) greater than that normally expected between congeneric species. The degree of difference was of the order typically exhibited between members of different but confamilial genera, for example as here between Loligo forbesi and Alloteuthis subulata (I=0.22). It is therefore concluded that Loligo gahi should no longer be regarded as a member of the genus Loligo. Genetic analysis of further species is necessary to clarify whether or not Loligo gahi should, as has been suggested on morphological grounds, be united in a separate genus with other American myopsid species also currently ascribed to the genus Loligo.