New data on the presence and biology of the eastern Pacific black ghostshark Hydrolagus melanophasma (Chimaeridae) from the Peruvian coast

Its diagnosis was based, among other characteristics, on the absence of the anal fin, a blunt snout and a large, slightly curved dorsal spine extending beyond the apex of the first dorsal fin, as well as a long second dorsal fin of uniform height. The species dimensions, head shape, colouration and reproductive aspects are also described and compared. Phylogenetic analyses based on the mitochondrial genes cytochrome oxidase subunit 1 (COI) and 16S rRNA clearly discriminate H. melanophasma from its congeners.

The sequences in this study clustered closely with two other 16S sequences of the same species reported from Mexico. While no previous COI sequences were available, this study is the first record of COI sequences for the species in a public database. Hydrolagus melanophasma is currently classified as Least Concern by the IUCN.

However, data on catch volumes in Peru are almost non-existent and, given the fragility of chondrichthyan populations, a detailed study of their catches is warranted to assess their conservation status in a more documented manner.