Dogfish

dogfish, (order Squaliformes), any of several small sharks making up an order of chondrichthyian fishes composed of the families Centrophoridae (gulper sharks), Dalatiidae, Echinorhinidae, Etmopteridae, Oxynotidae, Somniosidae, and Squalidae. In North America the name is also used for a freshwater fish, the bowfin.

spiny dogfish

The spiny dogfishes of the family Squalidae possess a sharp spine in front of each of their two dorsal fins. The most widely known species is Squalus acanthias, called the spiny dogfish, spurdog, or skittle dog. It is abundant along northern Atlantic and Pacific coasts; a closely related, if not identical, form inhabits the southern half of the world. The spiny dogfish is gray, with white spots, and is about 60 to 120 cm (2 to 4 feet) long. Often found in dense schools, it preys on fishes and various invertebrates. It is often a nuisance, as it takes baits and damages fishing nets, but it is edible and also yields liver oil and is ground for fertilizer. Its dorsal fin spines are associated with small venom glands and can cause painful wounds.