Black dogfish to the clade formed by the granular dogfish ("C. granulatum") and combtooth dogfish ("C. nigrum"). The black dogfish is a common species, with a wide but discontinuous distribution in the temperate waters of the Atlantic Ocean; its range abuts, but does not extend into, the Arctic Ocean. In the northeast, it occurs from Iceland to Sierra Leone, including the Faroe Islands, southern Norway, and the Rockall Trough and Porcupine Seabight off Ireland. In the northwest, it is found from southern Greenland and Baffin Island to Virginia, being particularly abundant in the Laurentian Channel, and may occur further south to the
Rockall Ledge, each secured by four 80-tonne rock-anchor bolts. Establishing that the rock is part of the United Kingdom and its development as a light beacon facilitated the incorporation of the island into the District of Harris in the County of Inverness in the Island of Rockall Act 1972 and reinforced the UK Government's position with regard to seabed rights in the area. In 1978, eight members of the Dangerous Sports Club, including David Kirke, one of its founders, held a cocktail party on the island. Former SAS member and survival expert (the Irish born) Tom McClean lived on the island