Dusky smooth-hound 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. "M. canis" can be known as smooth dogfish, Atlantic smooth dogfish, dusky smooth-hound, grayish, nurse shark, smooth dog, or smooth-hound. It was originally named "Squalls canis". In Latin, "mustelus" translates to weasel
Spotless smooth-hound longer than the upper one. The teeth are molar-like with low cusps. Both the dorsal fins have a curved trailing edge and the distance separating them occupies about 20% of the total length of the fish. The dorsal surface and flanks are grey or greyish-brown and the ventral surface is paler. The colour is uniform and there are no spots or bands of darker or lighter colour. The spotless smooth-hound is found in the temperate and tropical Pacific Ocean between 40°N and 11°N, off the coast of Vietnam, Japan, China and Taiwan, and possibly the Philippines. It occurs on the