Pigment variation in cetaceans: albinism, leucism, melanism

When whales step out of grey

Migaloo the white humpback whale, pink dolphins (boto, Indus river dolphin), melanistic killer whales, white dolphins: cetacean pigmentation shows striking variation. This database lists the documented morphs.

Going further

Colour variation is fascinating: Migaloo and other famous individuals, morphometrics, hybridisation and sequenced genomes.

Albinism and leucism: why are some cetaceans white?

Albinism and leucism are genetically distinct. Albinism is caused by a failure to produce melanin, due to mutations in the TYR gene (tyrosinase); it is often accompanied by pink eyes. Leucism affects the migration or the expression of melanocytes but leaves the pigmentation of the eye intact.

Migaloo, the famous white humpback whale of Australia observed since 1991, is leucistic rather than albino. Dozens of other white cetaceans have been documented: white killer whales off Kamchatka, pale Risso’s dolphins, mottled sperm whales. Conversely, the pink boto of the Amazon (Inia geoffrensis) owes its colour to the scars of male-male fighting, which gradually whiten its originally grey skin, a case of acquired rather than genetic coloration.