Deepwater Skate

Bathyraja richardsoni

Description

The deepwater skate (or Richardson's ray) is diamond-shaped and lacks large thorns on its disc and the anterior part of its tail which are characteristic of many other species of skate. Mature males, however, do have prominent alar thorns on the outer, dorsal edges of both pectorals. Claspers in mature males are very long, extending up to approximately three quarters of the distance from the axils of the pelvics to the tip of the tail. Coloration, both on the dorsal and ventral surface, is a uniform grey or brown.

Size

The deepwater skate reportedly reaches a maximum total length of approximately 175 cm.

Range

This is a very poorly known, rarely observed species. A few specimens have been found in the eastern North Atlantic southward from the English Channel to the Bay of Biscay. The only reported captures of the deepwater skate in the western North Atlantic occurred via bottom longline during deepwater explorations by the research vessel A.T. Cameron from 1965 - 1967. Specifically, eighteen specimens were taken from off southern Labrador to off Georges Bank .

Habitat

The deepwater skate - as its name implies - is a bathydemersal, marine species occurring in waters from 1320 to 2500 m depth. Specimens have been captured on the lower parts of continental slopes, on submarine rises, and on adjacent deep-sea plains. In Canadian waters, all specimens were caught at depths ranging from 1370 - 2360 m, and at temperatures of 3.26°C to 3.85°C.

Life History

Unknown

Diet

The deepwater skate feeds mainly on fishes. Small amounts of shrimp are also consumed.

Reproduction

The deepwater skate is oviparous, laying eggs with distinct, horn-like projections. Fecundity is assumed to be less than 100 young annually.