New benthopelagic calanoids (Crustacea: Copepoda) from deep Atlantic waters

Abstract

Two new genera and species of benthopelagic clausocalanoid copepods are described from collections taken at abyssal depths close to the sea bed in the tropical Atlantic. Procenognatha semisensata gen. et sp. nov. and Ranthaxus vermiformis gen. et sp. nov. both share the presence of sensory setae on maxilla and maxilliped with all other members of bradfordian copepods of Clausocalanoidea, but do not fit the diagnosis of any of these genera. Procenognatha differs from other bradfordians by the swollen basal half of the proximal posterior seta on the maxillule praecoxal arthrite and by having three sclerotized terminal setae on the maxilla endopod. Ranthaxus is distinguished by the presence of worm-like sensory setae on maxillule, maxilla, basis and endopod segment 5 of maxilliped and by welldeveloped, elongated worm-like sensory setae of maxilliped syncoxa.