Common smooth-hound on its underneath. It is often confused with the starry smooth-hound which has white spots on its back. The starry smooth-hound can often have faded spots which leads to misidentification. Another shark it is often confused with is the tope shark although the common smooth hound has a larger second dorsal fin. Due to the similarities between the common smooth-hound and other sharks, misidentification occurred for a long time. The common smooth-hound has two dorsal fins, an anal fin, a pair of pectoral fins, a pair of pelvic fins and a heterocercal tail. All of these fins help stabilise the
Dusky smooth-hound and "canis" translates to dog. "M. canis" has an allopatric relationship with "M. mustelus" (common smooth-hound) and a sympatric relationship with "M. norrisi" (narrowfin smooth-hound). "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