Cyprideis (Crustacea, Ostracoda) in Australia
Keywords: Cyprideis torosa, Cyprideis australiensis, Cyprideis westraliensis, Cyprideis consobrina, molecular phylogeny, 4 theta rule, valve morphology, soft part morphology
Abstract. The identity of Australian Cyprideis has been disputed for several decades. Here, we compare selected aspects of morphology and genetic diversity of two DNA regions (COI and ITS1) between European populations of C. torosa and a Cyprideis population from southern Western Australia, tentatively assigned to C. cf. australiensis. We find that the European and Australian specimens belong to two different genetic species according to the 4 theta rule. We also find some differences in morphology between C. torosa and C. cf. australiensis that allow us to differentiate between these two species. Furthermore, we doubt the assumed synonymy between C. australiensis and C. westraliensis. It would thus seem that at least one, maybe two or even more, species of Cyprideis exist in Australasia that are not part of the near-cosmopolitan C. torosa cluster. The status of Cyprideis consobrina from New Caledonia should also be investigated in light of these new findings.