North Pacific Spiny Dogfish

The Pacific spiny dogfish are small and skinny members of the family Squalidae. Throughout the entire Pacific Ocean, male and female dogfish measure up to be around 1.3–1.6 metres (4.3–5.2 ft). Female Pacific dogfish reach a weight of 6.8–10 kilograms (15–22 lb) by maturity, while the males tend to be much smaller in weight. The average maturation of the sharks normally take up to around 25 years. They can even live to the age of 100 years old. This makes the Northeast Pacific spiny dogfish the longest living out of all dogfish.

Dogfish in general live in three main areas of the ocean: the Pacific, Atlantic, and Indian ocean. While dogfish can be found all around the world, this specific type of spiny dogfish can be found in the Pacific Ocean. Spiny dogfish in the northern Pacific Ocean have recently been reevaluated and found to constitute a separate species, now known as the Pacific spiny dogfish.

The Pacific dogfish is an elasmobranchs or cartilaginous fish which includes sharks, skates and rays. Dogfish are carnivorous or meat eaters. Their teeth are sharp and are inclined laterally in order to cut through their prey. The Pacific dogfish usually eat mollusks or crustaceans such as squid, krill, and shrimp. They also eat other small sharks and fish. There is no difference between the diets of male and female dogfish. Their prey are usually found on the sea floor, so the Pacific spiny dogfish has to scan the bottom in order to invest in their prey. Elasmobranchs consume very little carbohydrates and glucose. During times of starvation, they rely on ketone bodies to give them enough energy to survive. Cartilaginous fish are able to endure severe hypoglycemia due to their ketone oxidation. Squalus suckleyi are able to eat more carbohydrates compared to other elasmobranchs.

The Pacific dogfish have a longer reproduction rate compared to other sharks, but have the same reproduction characteristics as Squalus acanthias . The gestation period for spiny dogfish is normally 18 to 24 months. Dogfish that live in cooler water may have an increased duration of pregnancy. Females are also known to migrate from deep to shallow water as the pregnancy continues. This migration pattern is known to influence embryonic growth. Baby dogfish, also known as pups, found near Newfoundland had an average of 1.1 cm/month and 24 month pregnancy period, while a warmer area such as Massachusetts had an average of 1.3 cm/month and 20-22 month pregnancy period. The sexual maturity of a dogfish is hard to determine because it varies anywhere from 10–30 years. Food supplies and water temperature also play a role in growth and development of the dogfish.

The Pacific dogfish poses no immediate threat to humans. It is rare to hear about this type of shark attacking and injuring humans. 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.