Spiny dogfish, also known as rock shark, rock cod, rock salmon, spurdog, mud shark and piked dogfish, is one of the best-known dogfish. It is gray or brownish in color on the top and pale grey or white on its ventral side, with irregular white spots on the top or sides of the body. Spiny dogfish can be distinguished by its two spines, one anterior to each dorsal fin and the lack of an anal fin. It has a caudal fin with asymmetrical lobes that forms a heterocercal tail. This shark forms the food of many people in Europe, the United States, Canada, New Zealand and Chile. It is also used as a fertilizer, liver oil and pet food. Read on to know more interesting and amazing information on the spiny dogfish.
Facts About Spiny Dogfish
Species: S. acanthias
Group Name: School
Length: Male: 2.6-3.3 ft, Female: 3.23-5.22 ft
Weight: 15-20 lbs.
Lifespan: 25 years
Diet: Fishes and invertebrates.
Habitat: Warm waters of the Arctic and Antarctic regions.
Age of Sexual Maturity: Male: 11 years, Female: 18-21 years
Gestation Period: 22-24 months
Number of Offspring: 2-11
Interesting & Amazing Information On Spiny Dogfish
- Spiny dogfish is the world’s most abundant shark and is the predominant shark species in Alaska.
- The shark can live for over 100 years.
- It is gregarious in nature and travels in packs of hundreds to thousands of individuals.
- Spiny dogfish are found in depths of 3000 feet (900 m) below the surface.
- They are found worldwide in temperate and sub-arctic waters, and in the temperate and sub-arctic latitudes of the North Atlantic and North Pacific oceans. They are found off Chile and from central Baja California to Alaska to Japan.
- Some tagged spiny dogfish in the eastern North Pacific are known to have traveled long distances. One such case is of a dogfish that swam 4039 miles (6500 km) to Honshu, Japan, where it was captured 7 years after it was tagged off from the coast of Washington state.
- Spiny dogfish are seasonal migrants into Canadian waters. They appear off Nova Scotia, in the Bay of Fundy and off southwestern Newfoundland in June. They move into the Gulf of St. Lawrence and into waters off Southern Labrador and around the rest of Newfoundland by July. And by late fall, most of them migrate out of Canadian waters and move south to waters off North Carolina or New England.
- The female spiny dogfish are longer than their male counterparts are.
- The age and length of a spiny dogfish, at maturity, differs greatly with region. The age of maturity of a female spiny dogfish in the northeast Pacific Ocean ranges from 20 years and 3 feet to 35.5 years and 3.1 feet.
- The pups produced by these sharks are between 8 to 12 inches.
- Spiny dogfish are ovoviviparous i.e., females produce eggs that hatch within their body, and bear live young.
- The principal food of spiny dogfish is herring, sandlance, smelt and euphausiids. They also prey on some 27 other fish species, such as capelin, cod, haddock, hake, herring, menhaden and ratfish, and 13 varieties of invertebrates, like krill, crabs, polychaete worms, jellyfish, ctenophores, amphipods, squid and octopus.