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Spiny dogfish (Squalus acanthias) — Squalidae

Spiny dogfish

Squalus acanthias
Family: Squalidae
VU · Vulnerable

The Spiny dogfish (Squalus acanthias) is a brackish-water fish of the family Squalidae that grows up to 160 cm.

Length
160 cm
Water
Brackish
Depth
0–1,978 m
Diet
Carnivore
Behaviour
Schooling
Activity
Diurnal
Body shape
Elongated (eel-like)
Substrate
Sand / mud bottom
Danger
Venomous / poisonous
Range
Circumglobal in boreal and temperate waters; absent from the North Pacific (replaced there by Squalus suckleyi).
Edibility
Commonly eaten

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Description

The spurdog is a slender, small shark of the family Squalidae reaching about 160 cm. The back is blue-grey with a row of small white spots and the belly is white; an anal fin is absent. In front of each of the two dorsal fins stands a venomous spine that can inflict a painful wound. The species occurs circumglobally in cool, temperate waters, including the North Sea, hunting fish, squid and crustaceans. Spurdogs are ovoviviparous with an exceptionally long gestation of 18 to 24 months. Because of overfishing and slow reproduction the species is assessed as Vulnerable across much of its range.

Frequently asked questions

How do you recognise the Spiny dogfish?

The Spiny dogfish has an elongate, eel-like body, is mainly silver-grey and shows a spots pattern. Slender shark with a venomous spine in front of each dorsal fin and a row of white blotches on the blue-grey back; no anal fin.

Where does the Spiny dogfish live?

The Spiny dogfish lives in brackish water and is mostly found around sand or mud bottom. Circumglobal in boreal and temperate waters; absent from the North Pacific (replaced there by Squalus suckleyi).

How big does the Spiny dogfish get?

The Spiny dogfish grows to a maximum of about 160 cm. On average the species is around 100 cm.

Is the Spiny dogfish dangerous to humans?

The Spiny dogfish is venomous — handle spines with care and seek medical help after a sting if needed. For wounds from the venomous dorsal spines: immerse the wound in hot water (about 45 °C) to ease pain, clean it, and seek medical care if pain or swelling persists.

Is the Spiny dogfish edible?

Yes, the Spiny dogfish is commonly eaten.

Easily confused with

These species look like the Spiny dogfish and live in the same waters.

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All data

Identification

English name
Spiny dogfish verified
Scientific name
Squalus acanthias
Family
Squalidae
Other names
Common spiny fish; Darwen salmon; Dog fish; Dogfish; Piked dogfish; Spiny dogfish; Spurdog; Spotted spiny dogfish; White-spotted dogfish; Grayfish; Huss; Pacific dogfish verified

Appearance

Size class
Extra large verified
Max length (cm)
160 verified
Average length (cm)
100 verified
Body shape
Elongated (eel-like) sourced
Dominant colour
Silver / grey sourced
Pattern
Spots sourced
Tail shape
Crescent (lunate) sourced
Mouth position
Inferior (downward)
Lips
Thin
Barbels
No verified
Dorsal fins
Two separate sourced
Dorsal spines
Yes verified

Habitat & distribution

Water type
Brackish sourced
Substrate
Sand / mud bottom sourced
Min depth (m)
0 verified
Max depth (m)
1,978 verified
Natural range
Circumglobal in boreal and temperate waters; absent from the North Pacific (replaced there by Squalus suckleyi). verified
Origin
Native verified

Behaviour & biology

Diet
Carnivore verified
Diet (detail)
Worms, crustaceans, molluscs and benthic invertebrates
Social behaviour
Schooling verified
Territorial
No verified
Activity
Diurnal sourced
Reproduction
Separate sexes verified
Sexual dimorphism
Yes verified
Max. age (years)
75 verified
Seasonality
Highly migratory; historically formed large shoals segregated by size and sex. Exceptionally long gestation of 18-24 months. sourced
Special features
Slender shark with a venomous spine in front of each dorsal fin and a row of white blotches on the blue-grey back; no anal fin. sourced

For anglers

Edibility
Commonly eaten verified
Fishing method
Bottom fishing with natural bait (worm, shrimp or fish) on or just above the seabed.
Regulations source

Safety

Danger to humans
Venomous / poisonous sourced
First aid
For wounds from the venomous dorsal spines: immerse the wound in hot water (about 45 °C) to ease pain, clean it, and seek medical care if pain or swelling persists. sourced

Status & sources

Sources
FishBase via GBIF (DwC-A), CC-BY-NC 4.0

Same genus Squalus

More from the family Squalidae

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