North Pacific Spiny Dogfish

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. The dogfish has a cylindrical shaped body. This type of shark also contains a unique body coloring. The top half of the shark has a gray color with scattered white spots while the bottom half has a white/light gray color. 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 skin of the sharks used to be used as sandpaper once dried to do woodwork or even be used as leather, once the denticles are removed. Lastly, the Pacific spiny dogfish has a set of teeth specialized for grinding instead of tearing by the teeth being flat with sharp edges. If any of the teeth are worn down or broken, new teeth replace them from the two rows that are not being used to prey on other animals.

The Pacific dogfish's habitat consists of bays, including inshore and offshore waters. Female dogfish are usually seen in inshore waters while smalls pups are seen maneuvering in offshore waters. These animals are usually spotted at the bottom of the continental shelf at the bottom of the sea. The Pacific dogfish prefers to live mainly in saltwater, but they can live in and tolerate brackish water (a mix of salt and fresh water).

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 length of a newborn Pacific dogfish is around 22 to 23 centimeters. Females seem to be significantly larger than male dogfish. At sexual maturity the male dogfish is 60–70 cm while the female is about 70–100 cm. This length difference can be caused by the reproduction process of the female. Their bodies need to be bigger to carry and protect their eggs within their bodies. Pacific dogfish are ovoviviparous. This means that they produce eggs that hatch within the body. The size of the litter ranges from 1 to 20 newborns. …