Also known as the salmon shark. Is found in the Bering Sea and off western North America. It lives from the surface down to moderate depths. The skin is dusky grey above and paler below with white markings. A strong swimmer, it has a wide tail that has a double keel (a second, short ridge running along the upper part of the lower lobe of the tail). The largest-known pacific porbeagle was 10 ft (3 m) long.