Both forms occasionally strand along our coasts. Risso s dolphin , Grampus griseus , are animals of warmer, deeper waters to the south of our area. They are believed to be squid hunters and the few sightings of live individuals may represent strays during warm water episodes or during northward movements of their favored prey. A few individuals have been found stranded on Cape Cod beaches. Striped dolphin , Stenella coeruleoalba , like the Risso s above, are animals of deep-water habitats to the south.
Most sightings are of stranded animals during the fall or early winter.
Their short, stout design is built for diving. Flippers are small and rounded. The dorsal surface tends to be dark, brownish-gray lightening toward the belly. They often have a dark line running from the mouth to the base of each flipper and a light blaze on the sides, forward of the dorsal fin. They range through the Northern Hemisphere of the Atlantic and Pacific Oceans.