Phylogenetic relationships among the Australian and New Zealand genera of freshwater crayfishes (Decapoda : Parastacidae)

We sequenced approximately 500 base pairs of DNA from the 16S region of the mitochondrial genome to estimate relationships among the freshwater crayfi sh genera of Australia and New Zealand. In total, 35 sequences were obtaine d, representing 32 species and all 10 genera native to Australia and New Ze aland. From these sequences, maximum likelihood, minimum evolution and pars imony estimates of phylogenetic relationships among the genera were obtaine d and compared with previous hypotheses concerning the relationships among the crayfish genera. Our results support the monophyly of each genus (excep t perhaps Euastacus) and the organisation of these genera into three major clades: the first clade contains the genera Engaeus, Tenuibranchiurus, Geoc harax, Gramastacus, and Cherax; the second clade contains the genera Parane phrops, Parastacoides, Euastacus, and Astacopsis; and the third clade conta ins the genus Engaewa. We reject the ecological hypothesis of Riek for two major clades of crayfish species. Finally, we provide a checklist of the Au stralian and New Zealand species as they are currently recognised.