The Pacific Spiny Dogfish is a common species of the family Squalidae, and re among the most abundant species of shark in the world.
Biology and Description:
Its distinctive snout, large eyes, and flattened head are just a few of the physical characteristics that give the Pacific Spiny Dogfish its distinctive look. This dogfish has a cylindrically shaped body. This species also is unknown for its unique body colouring, the top half has a gray colour and the bottom part has a white/light gray colour. The scales of the dogfish are composed of the same material of shark teeth called dermal denticles, making the skin hard and durable. Lastly, the Spiny Spurdog has a set of teeth specialized for grinding instead of tearing by the teeth being sharp by the edges. The structure of this species fins is another unique characteristic. They do not have an anal fin but they do have a special fin. Because of its name, this spiny dogfish has two spines that are in front of each dorsal fin. The two spines are known for their venomous nature used as protection against enemies such as other sharks, humans and even whales. The dorsal fins also give the shark advantages, the first dorsal fin helps the shark to keep its body stable while swimming and the second one aids the shark by generating thrust. The caudal fin is larger than normal, which makes the sharks maneuver through the water quickly and efficiently. The Pacific Spiny Dogfish has a unique system of ventilation. This shark has five gills on each side, but do not have gill covers like bony fish. The shark is able to breathe with these gills by swimming or staying in the current. It also has a special feature called spiracles, which are gills located behind the eyes that allow the shark to breathe while resting or eating. This species reaches a maximum size of 130 cm TL and maturity is reached approximately at 79-110 cm TL. This species is ovoviviparous with a reproduction rate longer than other sharks. Litter size ranges from 1 to 20 newborns. Fertilization often occurs from October to February.
The Pacific Spiny Spurdog is an elasmobranch or cartilaginous which includes sharks, skates, and rays.
Habitat:
The Pacific Spiny Spurdog is endemic to the North Pacific Ocean, from the west coast of North America to the coast of Japan and the Korean Peninsula. Inhabits a wide depth range from shallow waters all the way to 1,236 m and prefers waters of 7-15 degrees C.
Conservation:
Management exists from a small area of this species’ range, and it is still taken as a non-target catch in many fisheries or discarded at sea. Regulations are in place for British Columbia. This species is also included in the integrated fisheries management plan under “other species” with a total allowable catch.
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