This shark species is unusual in two major ways. First, it is one of only two species to have a sharp, venomous spine directly in front of its dorsal fins (the other species with this unusual defense mechanism is the Horn Shark, which is not native to Oregon). The Spiny Dogfish also has no anal fin, which is common on most sharks. Its back is covered in white spots over a gray or brown colored body.
Spiny Dogfish are widely dispersed throughout the Pacific Ocean, often hunting in schools which may include thousands of individuals. Like other sharks, they are opportunistic but due to their relatively small size, prefer to feed on smaller fish, krill, squid and octopus.
Spiny Dogfish live from the intertidal zone down to at least 3,000 feet (915 meters) and are comfortable in both sunlit shallows and dark ocean canyons. They are very abundant off the coast of British Columbia and Washington, but can be found as far south as Chile.