Morphological variation in relation to the taxonomy of the destructor group of the genus Cherax (Decapoda: Parastacidae)

2019-10-18T00:04:32Z (GMT) by Anthony Sokol
The present study was directed at clarifying the taxonomy of the destructor group of the genus Cherax. This group was defined by Riek (1969) to include four species, viz. C. destructor, C. albidus, C. davisi and C.esculus. Approximately 1600 specimens representing over 80 localities wereexamined. These included specimens from three outgroup species; C. rotundus,C. punctatus and C. dispar. Variation in sixteen metric and thirty multistatecharacters was analysed using bivariate (analysis of covariance) and multivariate (principal components analysis) techniques. Preliminary multivariate analyses investigating the efficacy of size-correction methods supported the use of residuals following regression. Ratios failed to remove the effects of size.

None of the taxonomic analyses supported the distinction of C. davisi or C. esculus from C. destructor suggesting that these two species should be synonymized with C. destructor. By contrast, C. albidus was found to be morphologically distinct. The pattern and timing of speciation of C. albidus and C. destructor are unclear but may relate to the increase in aridity in inland Australia during the late Tertiary. The analyses also indicated that heterochrony may underly the morphological divergence of these two species.