The whale's skin is often marked by pits or wounds, which after healing become white scars. These are now known to be caused by "cookie-cutter" sharks ("Isistius brasiliensis"). It has a tall, sickle-shaped dorsal fin that ranges in height from and averages , about two-thirds of the way back from the tip of the rostrum. Dorsal fin shape, pigmentation pattern, and scarring have been used to a limited extent in photo-identification studies. The tail is thick and the fluke, or lobe, is relatively small in relation to the size of the whale's body.