Humpback whales have a small dorsal fin located on a hump. The shape of the dorsal fin varies among the humpback whales. Right, bowhead, and gray whales have no dorsal fin. Gray whales have a dorsal hump followed by a series of bumps. Like the flukes, the dorsal fin is made of dense, fibrous connective tissue, with no bones.
Dorsal fins are often scarred or marked.
Photos of baleen whale dorsal fins can be used for photo-identification. Their narrow elongated upper jaw bones arch upwards to house extremely long baleen. The lower jawline is deeply curved upwards in profile. Encrusting growths, called callosities, on the head, jaws, and blowhole areas of right whales are yellow-white. Accumulations of natural markings such as these aid researchers in photo-identification studies.