Author Robert Hamilton (1794–1868)
English: Black Mouthed Dog Fish
Subject: Dogfish
Tag: Fish
Date 1866
Source/Photographer
English: Hamilton, Robert (1866) British Fishes, Part II, Naturalist's Library, vol. 37, London: Chatto and Windus
Source: https://commons.wikimedia.org/wiki/File:FMIB_36416_Black_Mouthed_Dog_Fish.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.