The genus Metacyclops Kiefer in Australia (Crustacea: Copepoda: Cyclopoida), with description of two new species

Abstract

Two new species of the genus Metacyclops Kiefer, 1927 are described from subterranean waters of Western Australia, one from the Kimberley region and the other from the Pilbara region. They both belong to the "trispinosus"-group, which has a clear Eastern Gondwana connection and the centre of diversity in Australia. A phyletic tree of this group in Australia is proposed. Metacyclops kimberleyi sp. nov. is distinguished from other members of the group by at least two autapomorphies: the exceptionally long dorsal seta on the caudal rami and the maxilliped with only seven armature elements. The only clear autapomorphy of M. pilbaricus sp. nov. seems to be its unusual body shape. An antenna without exopod and the second endopodal segment of this appendage with only six setae is a synapomorphy that suggests a close relationship between these two new species. As the genus Metacyclops in Australia already has seven valid species, a key to aid in their identification, as well as a map of their distributions, are presented.