589 Spiny dogfish Squalus acanthias The spiny dogfish, spurdog, mud shark, or piked dogfish, Squalus acanthias, is one of the best known of the dogfish which are members of the family Squalidae in the order Squaliformes. While these common names may apply to several species, Squalus acanthias is distinguished by having two spines and lacks an anal fin. It is found mostly in shallow waters and further offshore in most parts of the world, especially in temperate waters. 160617 Spiny dogfish 589.jpg image/jpeg 31080 2012-04-20T09:36:34Z 616 Aquatic foods Fishes Type 1 2011-02-09T00:37:50Z 2019-05-14T18:05:27Z false specific 7797 true FOOD00575