Spiny dogfish (Squalus acanthias) at the Josephine Marie shipwreck, Stellwagen National Marine Laboratory (cropped and adjusted from original).
Date
Source https://marinelife.noaa.gov/media_lib/preview.aspx?ID=7299&p=img
Author Doug Costa, NOAA/SBNMS
Source: https://commons.wikimedia.org/wiki/File:Squalus_acanthias_stellwagen.jpg

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. While these common names may apply to several species, Squalus acanthias is distinguished by having two spines (one anterior to each dorsal fin) 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. Spiny dogfish in the northern Pacific Ocean have recently been reevaluated and found to constitute a separate species, now known as "Pacific spiny dogfish", Squalus suckleyi.
Order: Squaliformes
Family: Squalidae
Genus: Squalus
Species: Squalus acanthias Linnaeus, 1758
Synonyms:
Acanthorhinus acanthias (Linnaeus, 1758)
Spinax acanthias (Linnaeus, 1758)
Squalus fernandinus Molina, 1782
Acanthias vulgaris Risso, 1826
Acanthias americanus Storer, 1846
Spinax acantheus Cuvier, 1863
Acanthias lebruni Vaillant, 1888
Squalus lebruni (Vaillant, 1888)
Squalus blainvillei (non Risso, 1827)
Squalus barbouri Howell-Rivero, 1936
Squalus tasmaniensis Howell-Rivero, 1936
Flakeus tasmaniensis (Howell-Rivero, 1936)
Koinga whitleyi Whitley, 1940
Koinga kirki Whitley, 1940
Squalus kirki (Whitley, 1940)