Mospicalanus schielae, a new genus and species of calanoid copepod (Crustacea: Spinocalanidae) from deep Antarctic water

Abstract

 A new genus and species, Mospicalanus schielae, collected at bathypelagic depth in the Antarctic Ocean, is described from female specimens and a stage V male. The new species is placed in the Spinocalanidae on account of the absence of fifth legs and leg 1 characteristics. It appears to be closely related to Mimocalanus Farran, 1908, sharing apomorphic characters such as the lack of a rostrum, reductions of setal armament on the mouthparts, and absence of an outer spine on the first exopod segment of leg 1. Mospicalanus schielae can be distinguished from other spinocalanid genera by the setation of the antennary exopod, the maxillule, and the paecoxal endite of maxilla. Diagnostic characters of Spinocalanidae and Bathypontiidae are also discussed in order to clarify affiliation of genera tentatively assigned to the latter family. An updated key is given for the spinocalanid genera.