Which whale species has callosities on its head?

Right whales have callosities on their heads. These are rough, raised patches of skin found around the blowholes, above the eyes, and along the jaw and chin. They are a defining feature of the genus Eubalaena and help researchers identify individual whales.

The callosities themselves are dark or gray, but they often appear white because they host dense colonies of cyamids, commonly called whale lice. Each right whale develops a distinctive pattern, much like a fingerprint, allowing scientists to recognize animals from photographs and track their movements, survival, and calves over many years.

Callosities are not the same as ordinary scars or barnacle growth. Their biological purpose remains uncertain, although proposed explanations include protection, display, and interactions between whales. The phrase “right whale” refers to three living species—the North Atlantic, North Pacific, and southern right whales—and all share this characteristic head pattern.