Spiny Dogfish

Squalus acanthias

Dogfish, grayfish, spurdog, piked dogfish, aiguillat commun, chien de mer

INTRODUCTION

The spiny dogfish may be the most abundant shark in the world and in Canada. In the western Atlantic, it ranges from the Bay of Fundy to Labrador, including the St. Lawrence Gulf and Estuary. It feeds on many commercial species and is thus considered a nuisance by the fishing industry. It is a gregarious shark that travels in large foraging schools as it follows its prey during seasonal migrations. It is believed to remain within Canada throughout the year although it normally* leaves the St. Lawrence for deeper water in winter. As of 2016, the spiny dogfish is the only shark that is fished commercially in Canada.

 

*A spiny dogfish was caught in the Saguenay Fjord in January 2015.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: November 6, 2016

VIDEO: Pacific spiny dogfish at Quadra Island, British Columbia. Images © GEERG

NAMES

Scientific name: Squalus acanthias* (Linnaeus, 1758)

Squalus: Latin = shark

acanthias: Greek = spines

*shark with spines

 

Common names: Dogfish, grayfish, spurdog, piked dogfish, aiguillat commun (Fr.), chien de mer (Fr.)

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

SIZE AND APPEARANCE

Maximum length: 1.6 m (5.2 ft)

Common length: 1 m (3.3 ft)

Maximum weight: 9.8 kg (21.6 lbs)

 

Its back and flanks are bluish grey with irregular white spots. Its underside is whitish. Both of its dorsal fins are preceded by spines. There is no anal fin. The Pacific spiny dogfish, Squalus suckleyi, is now considered a distinct species to the nearly identical Squalus acanthias.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

Spiny dogfish, Squalus acanthias, at Stellwagen Bank. Photo by NOAA

DENTITION

The teeth of the spiny dogfish are short and oblique in both jaws.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

Spiny dogfish teeth. Illustration by Garman (1913)

DISTRIBUTION (QUEBEC AND MARITIME PROVINCES)

In Canada, the distribution of the spiny dogfish extends from the Bay of Fundy to Labrador. It uses the entire water column from the surface to the bottom (up to 730 m, 2400 ft).

 

ST. LAWRENCE: The presence of Squalus acanthias in the St. Lawrence Gulf and Estuary is neither recent nor is it related to climate change.

ALL OBSERVATIONS LOGGED AND VERIFIED BY GEERG. CONTACT US FOR REFERENCES.


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AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

PREY

The spiny dogfish is an opportunistic predator that feeds on fish and invertebrates. It often hunts in foraging schools of hundreds of individuals which results in feeding frenzies.

 

Verified stomach contents: Capelin, cod, haddock, hake, herring, menhaden, ratfish, krill, crabs, polychaete worms, jellyfish, ctenophores, amphipods, squid and octopus.

 

Note: The spiny dogfish does not actively feed on marine mammals.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

VIDEO: Diving with spiny dogfish in Norway

REPRODUCTION

The spiny dogfish doesn't become sexually mature until 20 years old and its gestation period may last up to 24 months. Litters are between one and 14 pups.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

LIFE EXPECTANCY

The spiny dogfish may live up to 75 years.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 23, 2016

ATTACKS

Intentional attacks attributed to the spiny dogfish are nonexistant.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 29, 2016

FISHERIES

The spiny dogfish is the only shark species targeted by a directed fishery in Canada, which is mostly destined for export.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

STATUS

Scientific Name: Squalus acanthias

Taxonomy Group: Fishes

Range: Atlantic Ocean

Last COSEWIC Assessment: April 2010

Last COSEWIC Designation: Special Concern

SARA Status: No schedule, No Status

 

Click HERE to go to the COSEWIC profile page on the spiny dogfish.

AUTHOR: Jeffrey Gallant

LAST MODIFIED: October 30, 2016

Greenland Shark and Elasmobranch Education and Research Group (GEERG)

Quebec Shark Observatory (QSO)

Administration: Drummondville, QC

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