Small spurdog with a spine that is a powerful predator

The Shortspine spurdog (Squalus mitsukurii) is a dogfish, a member of the family Squalidae, found around the world on continental shelves in temperate and subtropical oceans between latitudes 45°N and 55°S, from the surface to 3,130 feet. Its length is up to 4.1 feet.


Family: Squalidae – Dogfish Sharks

Genus: Squalus 

Species: mitsukurii


Phylum– Chordata

Class– Chondrichthyles



Common NameDogfish Sharks

Family– Squalidae

Common NameDogfish Sharks




Average Size and Length: Shortspine spurdogs are born between 8.3-12 inches. Mature males are between 1.5-2.8 feet, and mature females between 1.6-3.3 feet. The maximum recorded length has been 4.1 feet.

Head: The head of the Shortspine spurdog is broad and the snout is long with barbels on the anterior nasal flaps. They have large eyes closer to the tip of the snout than the first gill slit.

Demographic, Distribution, Habitat, Environment and Range: The Shortspine spurdog is patchy worldwide. It can be found over continental and insular shelves and upper slopes on submarine seamounts and ridges on or near the bottom between the surface and 3,130 feet. However, they are mostly found between 328-1,640 feet.

Diet: The primarily feed on bony fish and invertebrates.

Aesthetic Identification: The Shortspine spurdog is a mostly slender shark. It is grey or grey brown above, and counter-shaded lighter below. The dorsal fins have dusky tips and the area of the posterior caudal notch is dusky. In young Shortspine spurdogs, these areas are black. The pectoral, pelvic and caudal fins have white posterior margins. The pectoral fins have shallowly concave posterior margins and narrowly rounded rear tips. The first dorsal fin is high and originates over or just behind the pectoral fin bases. The first dorsal spine is short and stout, giving the shark its name. It originates over the pectoral fin bases.

Biology and Reproduction: The Shortspine spurdog is ovoviviparous having 2-15 pups per litter. The number of pups increases with the female’s size. They have a long, 2-year gestation period. Males mature between 4- 11 years, and females between 15-20 years.

Behavioral Traits, Sensing and Intelligence: The Shortspine spurdog can often be found in large aggregations, in shoals, and in schools. The do segregate sex by depth and latitude.

Speed: The Shortspine spurdog is powerful.

Shortspine Spurdog Future and Conservation: There isn’t enough data to properly evaluate, however they are very vulnerable to commercial fishing, and therefore in reality are in danger.

Shortspine Spurdog Recorded Attacks on Humans: Not a threat to humans.