NEW TANTULOCARID POLYNYAPODELLA-AMBROSEI GEN. ET SP. NOV., (BASIPODELLIDAE) FROM THE NORTHEAST WATER POLYNYA (GREENLAND) WITH EMPHASIS ON THE PHYLOGENY OF ITS HOST GENUS CERVINIA (COPEPODA, HARPACTICOIDA)

Several life cycle stages of a new genus and species of Tantulocarida are described from the Arctic Northeast Water Polynya (NEW) on the Eas t Greenland shelf. Polynyapodella ambrosei gen. et sp. nov. was found to infest a new species of the deepwater harpacticoid genus Cervinia ( Cerviniidae). The tantulocarid is placed in the family Basipodellidae on account of the male trunk sac formation and appears to be most clos ely related to Nipponotantulus heteroxenus recorded from southern Japa n. The harpacticoid host Cervinia sp. shows a close affinity with Cerv inia langi and C. philippinensis sp. nov. (proposed for C. langi sensu It (o) over cap (1983)). Analysis of the phylogenetic relationships w ithin the genus Cervinia revealed that it represents a paraphyletic ta xon as it is currently diagnosed. The genus Pseudocewinia, previously regarded as a junior subjective synonym of Cervinia, is reinstated to accommodate the type-species P. magna. Cervinia tenuiseta shares a sis tergroup relationship with the genus Expansicervinia and is assigned t o a separate genus Brotskayaia gen. nov. The genus Cervinia is redefin ed to include the species of the synarthra-group, the type-species C. bradyi and C. pilosa. Neocervinia gen. nov. is proposed to accommodate C. tenuicauda and C. unisetosa. The taxonomic position of C. tenuiset a sensu For (1969), C. synarthra sensu For (1967) and C. brevipes is b riefly discussed as well as the taxonomic implications caused by the e xtreme sexual dimorphism displayed by some species of Cervinia.