The black dogfish (Centroscyllium fabricii) is a deepwater, bottom-associated shark found along the continental shelf and slope, including in the Gulf of St. Lawrence[1]. Because it inhabits depths far beyond the reach of recreational divers, observations are generally limited to incidental captures by deepwater trawlers and other fishing gear.

The species is sometimes confused with the similar-looking Portuguese dogfish, although the latter possesses smaller and less conspicuous dorsal spines in front of each dorsal fin.

The black dogfish and Greenland shark are currently the only verified shark species known[2] to occur year-round in the Gulf of St. Lawrence, whereas all other sharks documented in the region are considered seasonal visitors.

(1) NOAA Fisheries
(2) There are two known outlier cases of the spiny dogfish (Squalus acanthias) being caught by ice fishers in the Saguenay Fjord in winter (Gallant, J., unpublished data).

• Average length between 60 and 75 centimetres.
• Uniformly black to very dark brown in colour, sometimes with lighter markings on the fins or underside.
• Large oval eyes adapted for deepwater vision, often producing a greenish reflection under light.
• Long, prominent white dorsal spines located in front of both dorsal fins.
• Slender body with no anal fin.
• Deepwater species inhabiting depths of approximately 275 to 1,600 metres.
• One of only two verified shark species known to occur year-round in the Gulf of St. Lawrence.
• Year-round presence throughout Atlantic Canada and Québec, including the St. Lawrence Estuary.

The black dogfish is found year-round throughout the Gulf and Estuary of the St. Lawrence, as well as along the continental slopes of the North Atlantic from the northeastern United States to Greenland and Europe. In Atlantic Canada, the species is particularly abundant in the deep waters of the Laurentian Channel, which appears to constitute an important habitat for the species.

The black dogfish (Centroscyllium fabricii) has not currently been assessed by COSEWIC (Committee on the Status of Endangered Wildlife in Canada) and does not receive legal protection under Canada’s Species at Risk Act (SARA).

Globally, the species is listed as Least Concern by the International Union for Conservation of Nature (IUCN) because of its broad North Atlantic distribution and the apparent stability of several populations, including in parts of Atlantic Canada. Nevertheless, the black dogfish remains vulnerable to deepwater fishing pressure because of its slow growth, late maturity, and low reproductive rate.

The species is commonly taken as by-catch in deepwater trawl and longline fisheries targeting Greenland halibut and other commercially valuable species. In the northwestern Atlantic, including Atlantic Canada and the Gulf of St. Lawrence, available data suggest that populations declined substantially between the late 1970s and mid-1990s before later stabilising. Its deepwater habitat may provide partial refuge from fishing activity.