It can be distinguished from smooth dogfish by the rows of small white spots on its side and by the two sharp spines that protrude in front of its large dorsal or back fins. Spiny dogfish feed on small fish as well as shellfish and are most often encountered during winter cod fishing trips. Land dogfish with care to minimize damage to the fish and to avoid injury. Stun dogfish and bleed them immediately by cutting off the tail. As soon as the tail is cut off, gut and dress the fish.
Adequate ice is essential to preserve the quality of dogfish.
Surround dressed dogfish completely with ice to preserve its flavor and to prevent the flesh from developing an ammonia flavor. Unless dogfish are properly chilled to prevent bacterial growth, strong ammonia smells and flavors can develop rapidly. If you cannot process your catch immediately, ice down the whole fish and dress it as soon as possible. Before freezing or preparing fresh dogfish, cut fillets away from the cartilage backbone or cut the fish into steaks. Because ammonia flavors may develop, it is widely suggested that dogfish meat be soaked to neutralize minor taints.