Molecular Systematics of the Long-Snouted Deep Water Dogfish (Centrophoridae, Deania) With Implications for Identification, Taxonomy, and Conservation

According to the most recent taxonomical revision, deep-sea dogfish genus Deania encompasses four species. Three of them, D. calcea, profundorum , and hystricosa occur in North Atlantic. Whilst can be identified by presence a subcaudal keel, other two species are not easily visually distinguished. Uncertainties over identification raises concerns stock units whether management plans adequate. In this study we compared onboard visual specimens, with morphological inspection skin denticles under stereo microscope independent molecular assignment using markers. Particular emphasis was paid specimens as calcea NE Atlantic where these potentially sympatrically may confused. past have been discriminated on basis size (skin roughness), but our showed that crown length covaries (and sex), irrespective species, therefore is reliable character should used discriminate between Phylogenetic analyses did indicate distinct lineage from . Interestingly, however individuals (specimens from: UK, Azores Is., Madeira Is. Seine seamount) formed well-defined sub-clade nested within clade, possibly signature vicariance event or result coalescent stochasticity.