A new genus of Canuellidae (Copepoda, Harpacticoida) associated with Atlantic bathyal sea-urchins

Both sexes of Echinosunaristes bathyalis gen. ct sp. n. are described from the rectum of a deepwater spatangoid sea-urchin Palaeopneustes sp. taken off San Salvador Island, Bahamas. The new genus displays strong sexual dimorphism in body form, size, antennules and caudal rami. E. bathyalis can also be readily distinguished from the other members of the family by the specialized geniculation mechanism of the male antennule, the atypical reductions in the mouthparts and the unusual facies of the swimming legs. On the basis of the structure of the genital field in both sexes, Echinosunaristes is placed in the Sunaristes lineage which groups species that arc primarily associated with crustacean hosts. A ncw genus Intersunaristes is established to accommodate Sunaristes curticaudata Thompson & A. Scott, 1903 and S. dardani Humes & Ho, 1969. Canuella paenelanitica Fiers, 1992 is formally transferred to the genus Elanella Por, 1984. Records of Canuellidae associated with other invertebrates arc compiled and a key to the 17 genera of the family is presented.