Austromesocypris bluffensis sp. n. (Crustacea, Ostracoda, Cypridoidea, Scottiinae) from subterranean aquatic habitats in Tasmania, with a key to world species of the subfamily

Abstract. Austromesocypris bluffensis sp. n. is described and we report another species, Austromesocypris sp., both collected from subterranean aquatic habitats in Tasmania. This discovery adds a major taxonomic group to the already diverse invertebrate cave fauna of Tasmania, and is of interest because, globally, obligate subterranean aquatic species (stygobites) are poorly represented within the family Cyprididae. The genus Austromesocypris Martens, De Deckker & Rossetti, 2004 is otherwise known to comprise entirely “terrestrial or semi-terrestrial” species. The second species is not described because only juvenile specimens were collected. Both species stand apart from their congeners by the carapace shape, which is rectangular in Austromesocypris bluffensis and triangular and asymmetrical in the unnamed species. Another unique feature of the new species is the almost symmetrical uropodal rami. We also identify some broader systematic issues within the Scottiinae including the position of two New Zealand species, Scottia audax (Chapman, 1961) and Scottia insularis Chapman, 1963 in the genus, and point out their closer relationship to the Gondwana genera of Scottiinae, Austromesocypris and Mesocypris Daday, 1910, than to the Palearctic genus Scottia Brady & Norman, 1889, based on the morphology of the maxillula and mandibula. The identity of the Australian records of Scottia audax (Chapman, 1961), Austromesocypris australiensis (De Deckker, 1983) and the Boreal records of Scottia pseudobrowniana Kempf, 1971 are all considered doubtful. A key to the world species of Scottiinae is provided.