Ekleptostylis heardi (Diastylidae), a new cumacean species from South Atlantic waters

Abstract

A new species of Diastylidae in the genus Ekleptostylis was discovered among cumacean specimens collected at two stations in the South Atlantic by the RN Eltanin in 1962. The new species, E, heardi, features a smooth, unornamented carapace, a rounded distal process on the basis of the second peraeopod of males, and a telson which is shorter than the telsonic somite and which, in males, exhibits a flattened dorsal process strongly produced posteriorly over the terminal part. The characteristic telson process is shared by its only other congener, E. walkeri (Calman, 1907) and by the similar Diastylis pseudinornata Ledoyer, 1977, which also occurs in the South Atlantic. Both sexes of E. heardi differ from the preceding two species and from other similar species of Diastylis by the spination of the telson, uropods, and third maxilliped, and by other aspects of the carapace.