The Columbia Encyclopedia, Sixth Edition. Columbia Encyclopedia World Factbook Columbia Gazetteer American Heritage Coll. Spiny dogfishes have two spines, one in front of each dorsal fin, and lack an anal fin. Its gray skin is speckled with white. The spines in this species contain venom that can cause a very painful wound.
Spiny dogfishes migrate seasonally, preferring water within a certain temperature range.
They feed on a variety of fishes and invertebrates and cause great damage to populations of commercially valuable fish. In Europe they are fished for food. Other members of the spiny dogfish family are found in deep water. Of no commercial value, it migrates seasonally and feeds on small fishes and invertebrates. Like the spiny dogfish, the smooth dogfish is much used for dissection by students of vertebrate anatomy.