The Pacific Dogfish, also called the Pacific Spiny Dogfish, is a small, slim shark of the North Pacific that's common along the U.S. West Coast. It's gray with white spots and has a sharp, mildly venomous spine in front of each . It lives remarkably slowly: females carry pups for up to two years, don't mature until about age 35, and some live more than 80 years.
Appearance
- Appearance
- A slender shark with a narrow, pointed snout. It's gray above with white spots and white below. There's a spine in front of each of its two dorsal fins and no . Adults are usually 2.5–3.5 ft (76–107 cm) long; females are bigger than males.
Look-alikes
It lives in the Atlantic (including the U.S. East Coast) and southern oceans, not the North Pacific, so location is the easiest clue. By eye the two are very hard to tell apart; scientists separate them by body measurements and DNA.
Why they get mixed upThey were treated as one species until 2010.
Where it lives
- Typical habitats
- Bays and inland seas
- Continental shelf
- Range
- Ranges from the Bering Sea to Baja California, and across the North Pacific to Japan and Korea. It's more common off the U.S. West Coast and British Columbia than off Alaska, and is abundant in inland seas such as Puget Sound and San Francisco Bay.
- Preferred conditions
- Prefers cool water around 45–59°F (7–15°C). Most live shallower than about 1,150 ft (350 m), though they've been found as deep as about 4,050 ft (1,234 m). Young dogfish stay near the surface and move to the bottom as they grow.
- Migration
- Tagged fish show seasonal and daily movements along the coast. One dogfish tagged in Queen Charlotte Sound, British Columbia, was later caught off northeastern Japan.
Behavior
- Diet
- Mostly small schooling fish such as herring, plus shrimp, crabs, and squid.
- Social life
- Often travels in schools of hundreds or thousands, usually sorted by size and sex.
Life cycle
- Reproduction
- Fertilization is internal and pups are born live. A female can have up to 22 pups, depending on her size, usually giving birth in shallow bays in the fall. Newborns are 8.5–12 in (22–30 cm) long.
- Gestation
- 18–24 months, one of the longest of any shark.
- Time to maturity
- Off the U.S. West Coast, females mature at about age 35 and males at about 19.
- Lifespan
- Sometimes more than 80 years.
Cautions
- Cautions
- The dorsal spines carry a mild venom. It's otherwise harmless to people, but handle caught fish carefully.
Name and classification
- About the name
- For many years it was lumped with the Atlantic Spiny Dogfish (Squalus acanthias). A 2010 study showed the North Pacific population is a separate species, and its old name, Squalus suckleyi, was brought back. Older sources may call it S. acanthias.
Conservation
- IUCN Red List
- LCLeast ConcernLow risk of extinction
- Threats
- Because it grows slowly and has few young, it can be overfished easily. The U.S. Pacific coast stock is currently not overfished.
Culture and stories
- Culture and stories
- During the 1940s its livers were a leading U.S. source of vitamin A, and the liver fishery on the Pacific coast ran until about 1950.
- The meat is edible: white, firm, and mildly sweet, and oilier than most sharks.
More species to explore
Record what you meet and build your own collection
Your photos are kept with their date and place, and you can fill regional albums one species at a time.