Pseudometeorina mystica gen. et sp nov., a new Idyanthidae Lang incertae sedis (Copepoda, Harpacticoida) from the Guinea Basin (eastern tropical Atlantic)

Pseudometeorina mystica gen. et sp. nov. was recorded in 2005 during Cruise M 63/2 of RV Meteor in the Guinea-Basin. The new species shares several apomorphies with Styracothorax gladiator Huys, 1993 Aspinothorax insolentis Moura and Martinez Arbizu, 2003 and Meteorina magnifica George, 2004 (body slender and of rather triangular shape, tapering posteriorly; female antenna with 1-segmented exopod; antenna endopod-2 with only 3 lateral setae; bases of swimming legs 1-4 transversely elongate, approximately twice as wide as coxa; exopod of first swimming leg 2-segmented), indicating a strong affinity to Idyanthidae Lang, 1944. Noteworthy are pronounced morphological similarities with M. magnifica, which is the rationale for the assignation of the generic name Pseudometeorina. Nonetheless, P. mystica gen. et sp. nov. surprisingly has none of the autapomorphies of Idyanthidae, lacking particularly the sexually dimorphic endopod in the second swimming leg of the male, which is a very specific derived character of the family. Pseudometeorina mystica gen. et sp. nov. is described, its phylogenetic position is discussed, and the new species is tentatively placed into Idyanthidae as species incertae sedis.