Specialized family of Acorn Barnicle (Coronula diadema) in generally only found on Humpback Whales and result in the white patches left on the whales skin when they fall off. A type of gooseneck barnacle may also attach itself to the shell of the Acorn Barnacle.
A completely different species of barnacle (Cryptolepas rhachianecti) will grow on Gray whales.
Generally found attached to the head and leading edge of fins on various migratory baleen whales. Grow to dramatic proportions compared to their relatives, and filter feed on the passing water as the whale swims.
A single Humpback whale may carry up to 450 kg of barnacles.
It is thought that some ‘fight’ males may use the barnacles that grow on their fins as a weapon against potential predators as well as in mating rituals.