Abstract
A new species of deep-sea digenean, Steringophorus merretti n. sp., is described from the bythitid fish Cataetyx laticeps in deep waters of the Goban Spur, Northeastern Atlantic. It is distinguishable from other described members of the genus by its tiny eggs and large cirrus-sac. A phylogenetic tree, based on 28S rDNA sequences, indicates that this species is embedded within a clade of deep-sea species and is sister to the eurybathic species S. thulini Bray & Gibson, 1980. Steringotrema robertpoulini Pérez-Ponce de León, Anglade & Randhawa, 2018 falls within the Steringophorus Odhner, 1905 clade. In view of this the morphological and biological characteristics of species of Steringophorus and Steringotrema are discussed.