Genetic variation in the rock lobstersJasus edwardsiiandJasus novaehollandiae

Abstract

Twenty‐one proteins encoded by 33 scoreable genetic loci were surveyed in three samples of Jasus edwardsii from New Zealand and in one sample of Jasus novaehollandiae from Tasmania. Only one polymorphic locus, Est‐1, was found in J. edwardsii and two polymorphic loci, Est‐1 and Ldh, in J. novaehollandiae. Est‐1 allelle frequencies in J. edwardsii were similar in the three geographically isolated samples. Together with the biological data this suggests that J. edwardsii forms one stock. J. novaehollandiae differed from J. edwardsii only in allele frequencies at the Ldh locus. From Nei's measure, a genetic distance of 0.003 was found between the two species. This small genetic distance and the minor morphological differences suggest that they are con‐specific populations. A more extensive biochemical and morphological survey of the two lobsters is required to determine their specific status. Low levels of genetic variation were found in J. edwardsii, heterozygosities 1.2–1.7%, and J. novaehollandiae, heterozygosity 2.8%. Within the Crustacea, decapods in general have low heterozygosities but high levels have been found in euphausiids. It is suggested that this is related to life cycle heterogeneity which might be an important factor in determining genetic variation.