On Caledromus robinsmithi, a new genus and species of Psychrodromini Martens, 2001 (Crustacea, Ostracoda, Herpetocypridinae) from New Caledonia (Pacific Ocean)

The New Caledonian Archipelago is a hot spot for biodiversity and endemism. Where-as popular groups such as birds and plants are well-studied, invertebrate groups such as ostracods remain ill-known. Here, Caledromus robinsmithi gen. et sp. nov. is de-scribed from a single locality on 'Grande Terre', the main island of the archipelago. The new genus belongs to the Psychrodromini, one of the four tribes in the subfamily Her-petocypridinae (family Cyprididae). Caledromus gen. nov. can be distinguished from all other herpetocypridinids by a combination of the following factors: the absence of marginal septa in both valves, the mildly developed marginal valve structures, the small Rome organ on the A1, the total reduction of the five natatory setae on the A2, the rectangular second palp segment of the Mx1, the broad and asymmetrical palp on the female T1, the absence of additional postlabyrinthal coils in the Hp and the seta Sp of the CR which is a fixed spine. Because of the close similarity to the genus Psy-chrodromus, the new genus is thought to have Palaearctic affinities, contrary to other ostracod species in New Caledonia, which are either circumtropical or with Australian zoogeographical connections.

Automated summary

The New Caledonian Archipelago is a biodiversity hotspot with many unique species. This study introduces a new genus and species of ostracod, Caledromus robinsmithi, found on the main island of the archipelago. The new genus is distinct from others in the same subfamily based on several characteristics. It is believed to have affinities with a genus from the Palaearctic region.