Dusky smooth-hound

The dusky smooth-hound (Mustelus canis), also called the smooth dogfish or the dog shark, is a species of houndshark in the family Triakidae. This shark is an olive grey or brown in color, and may have shades of yellow or grayish white. Females live to 16 years and males have a lifespan of 10 years. M. canis was the first shark recognised to have viral infections.

Distribution

M. canis is found in marine and brackish waters and is demersal (bottom-dwelling) and oceanodromous (migratory in seas). They can be found between 42°N and 44°S and 100 and 46°W. M. canis in the North Atlantic migrates in response to changing temperature. In winter, they can be found in the Carolinas to the outlet of the Chesapeake Bay, and in summer from the mid-Atlantic to southern New England. They are most abundant on the East Coast, from Massachusetts to Florida, Brazil to Argentina, and in the Gulf of Mexico. They are mostly found in waters shallower than 60 ft (18 m), but can be found to 665 ft (200 m) deep.

Behaviour

M. canis feeds mostly on crustaceans, polychaetes, and mollusks. Smooth dogfish also eat squid, worms, small fish, razor clams, and sometimes scavenge discarded animal products. They are nocturnal scavengers and opportunistic predators. Their nocturnal activity helps them to take advantage of concentrations of crustacean prey.