A newly discovered Helicocranchia species (Cephalopoda: Cranchiidae: Taoniinae) in the northern Gulf of Mexico

Only two species of Helicocranchia—Helicocranchia pfefferi Massy, 1907 and Helicocranchia papillata Nesis, 1987—are currently accepted as valid. The genus is found globally in tropical and subtropical regions at depths to >1000 m (Voss 1980). We collected Helicocranchia specimens in the northern Gulf of Mexico during the DEEPEND project (Deep Pelagic Nekton Dynamics of the Gulf of Mexico; sampling 2015–2018) and from the western North Atlantic Ocean during two different research cruises. Physical examination of specimens found differences from recognized species in external pigmentation and in the morphology of the gladius rostrum. Molecular analysis of the COI gene in the specimens also revealed species-level differences. This study reviews current taxonomy and describes a new Helicocranchia species.