|During the GO Sars cruise in 2004 a few specimens of the family Liparidae were caught. Due to the gelatinous flesh and fragile skin of these fishes, they are notoriously difficult to identify, so the onboard identification was tentative. |
The responsibility of the identification was placed with Peter Rask Møller, who along with Masters Student Steen Knudsen was doing at study of the molecular phylogeny of the family. The snailfishes are distributed in all oceans and are especially common in Polar and deep-sea habitats. Records from the Mid-Atlantic Ridge, were almost unknown before MAR-ECO, and were therefore an exciting catch. In order to get the best possible identification of the specimens, world leading specialist on the group Natalia Chernova was invited to Copenhagen to work with the specimens.
Three of the specimens caught at depths of 1950 and 2107 m were assignable to the genus Paraliparis, but the dark colour did not match any known species in the North Atlantic. It was similar to the Paraliparis copei complex in many characters such as vertebral number, teeth mainly uniserial, gill opening pore-like, opercular flap undeveloped and eight caudal-fin rays. It was, however, clear that the specimens differ from other members of this group in number of vertebrae, dorsal fin ray counts and body colour. They were therefore described as a new species to science and named Paraliparis nigellus after the dark colouration. The description was published in Marine Biology Research.
In additions to the new species, 3 tiny, 4-5 cm long, specimens of snailfishes were caught. They were indentified as members of the dwarfed-snailfish genus Psednos, which were previously unknown from the Mid-Atlantic Ridge. They were identified as Psednos groenlandicus, a species known from a few specimens from off Greenland, and descried as late as in 2001, by Chernova.
In conclusion it is clear that MAR-ECO caught only a few snailfishes, but the few caught were very interesting, and significantly added to our knowledge about this group of deep-sea fishes.
By Peter Rask Møller