Author David Starr Jordan (1851–1931)
English: Dogfish, Squalus acanthias L. Gloucester
Subject: Dogfish
Tag: Fish
Date 1907
Source/Photographer
English: Jordan, David Starr (1907) Fishes, New York City, NY: Henry Holt and Company
Source: https://commons.wikimedia.org/wiki/File:FMIB_51681_Dogfish,_Squalus_acanthias_L_Gloucester.jpeg

The spiny dogfish, spurdog, mud shark, or piked dogfish (Squalus acanthias) is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order. It is found mostly in shallow waters and further offshore in most parts of the world, especially in temperate waters.