Spiny dogfish (Squalus acanthias) are possibly the most abundant living shark. An inshore and offshore dogfish of the continental and insular shelf and upper slopes. Usually near the bottom, but also in midwater and at the surface; occurs mainly between 10-200 m depth (Compagno 1984). Spiny dogfish are distributed in Northwest Atlantic waters between Labrador and Florida, are considered to be a unit stock in NAFO Subareas 2-6, but are most abundant from Nova Scotia to Cape Hatteras.

This is one of the most important sharks for fisheries because of its abundance in colder waters, utilization in various fisheries, and damage it does to gear and catches of other fishes. Catches of Squalus acanthias reached a peak in 1972 (73,500 t) then declined but in the last decade they have stabilized in a range between 36,000 and 51,000 t. Most of the catches reported to FAO have come firstly from area 27 (Northeast Atlantic) and then from area 21 (Northwest Atlantic) but in 1995 and 1996 catches taken in area 21 have exceeded those from area 27. The countries with the largest catches were Canada (5 536 t) and Norway (1 461 t). It is captured primarily in bottom trawls and with longlines and handlines, but also commonly with gill nets seines, fish traps, and other gear; it is also readily taken by rod and reel (Compagno 1984).