american smooth dogfish

Smooth dogfish

The smooth dogfish, Mustelus canis, is a species of shark. This shark is an olive grey or brown, and may have shades of yellow or grayish white. Females live to 16 years and males have a life span of 10 years.

Size and growth

Length for the smooth dogfish is up to 1.5 m (60 inches), with a maximum weight of 12 kg (27 lb). Smooth dogfish reach maximum size at 7 or 8 years of age. Average size of this shark is approximately 1.2 m (48 in). This species grows quickly, with males reaching maturity at 2 or 3 years of age, and females at 4 to five years of age.

Habitat

A common resident in bays, and other inshore waters, the smooth dogfish prefers shallow waters of less than 18 m (60 ft) in depth but may be found to depths of 200 m (650 ft). This species has also been found on occasion in freshwater although it is unlikely they can survive freshwater for extended periods of time. The smooth dogfish migrates seasonally, moving north in the spring and south in the autumn. It is primarily a nocturnal species.

Food

A scavenger and opportunistic predator, the smooth dogfish feeds primarily on large crustaceans, including lobsters, shrimp, and crabs, as well as small fish and mollusks. The flat, blunt teeth of the dogfish are used to crush and grind these prey items which have tough outer body coverings. Small fish that are preyed upon by the smooth dogfish include menhaden and tautog. Young smooth dogfish feed on small shrimps, worms, and crabs.

Reproduction

Mating occurs throughout most of the smooth dogfish's range from May through July. Following a gestation period of approximately 10 to 11 months, a litter numbering as few as 4 and as many as 20 is born during late spring or early summer. Larger females tend to have larger litters.

Importance to humans

In certain areas, the flesh of smooth dogfish is marketed as fresh or dried salted for human consumption. The smooth dogfish is often used as a laboratory animal and in public display at aquariums.