[4] Recent research, using meristic, morphological and molecular data led to the resurrection of the Pacific spiny dogfish as a separate species.

The slower growth rate and time of maturity could be related to the colder temperatures these sharks face.

These areas range from Korea to Japan and Russia, as well as the gulf of Alaska down to Baja, California.

Squalus suckleyi have a slow reproduction rate compared to other sharks, with their gestation period being roughly around two years.

The scales of the dogfish is composed of the same material of shark teeth called dermal denticles, making the skin very hard and durable.

The use of two spines on the outer body have been proven for the use of protection against enemies such as other sharks, humans, and even whales.

The first dorsal fin helps the spiny dogfish maintain a stable body position while swimming while the second aids in generating thrust.

[18] The caudal fin is larger than normal, which helps the sharks maneuver through the water quickly and efficiently.

First, the dogfish has water enter its mouth and exit through the parabranchial cavity, which then goes out through the five gill slits.

Finally, the fifth gill slit has water escaping while the Pacific spiny dogfish feeds on its prey.

[4] The Pacific dogfish's habitat consists of bays, including inshore and offshore waters.

Analyses of tagged dogfish have shown a seasonal north-south migration along the west coast of the United States and Canada as well as a seasonal pattern of dogfish tagged in the inside waters of the Puget Sound repeatedly leaving that area for outside coastal waters in the summer.

[23] Tagged dogfish released in Canadian waters off British Columbia were most often recaptured in the same area as released but 10 individuals were recaptured near Japan[24] Pacific spiny dogfish have been frequently captured over 1000 km from shore in salmon research gillnets in the North Pacific Ocean, suggesting that the trans-Pacific migrations from Canada to Japan could have passed through the open ocean rather than following the coast[25] The Pacific dogfish have a longer reproduction rate compared to other sharks, but have the same reproduction characteristics as Squalus acanthias .

Food supplies and water temperature also play a role in growth and development of the dogfish.

[6] The Pacific dogfish is an elasmobranchs or cartilaginous fish which includes sharks, skates and rays.

The only significant way that the Pacific dogfish can cause harm to a human is if a person gets near the venomous spikes that are located at the dorsal fin.

The main species of animals that threaten the Pacific dogfish population are sharks, Killer whales, seals, and larger bony fishes.

[30] The Pacific dogfish has relatively few predators, as its poisonous spines serve as a deterrent measure.

[31][32] For centuries, dogfish have been harvested on the Pacific coast for subsistence use and for their skin, which was used as a polishing material.

[33] Commercial fisheries first began targeting dogfish in the 1930s and commercial landings of Pacific spiny dogfish in the West Coast of the United States were highest in the 1940s, driven by a market for Vitamin A from shark liver oil.