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Why Right Whales Have Callosities

Right whales are among the largest baleen whales in existence. They can grow up to lengths of more than 60 feet, and their anatomy has distinctive features that set them apart from other species of whales. The callosities observed on right whales are one such characteristic. These are roughened patches of skin that can be seen on several different areas of the animal’s body. While their function has been understood for some time, there are still many mysteries that are not revealed regarding the symbiosis that they facilitate between right whales and several species of small crustaceans.

Right whales may not be the largest mammals in the ocean, but their impressive size definitely gives them the possibility to become the protector of other animals. These whales are typically between 36 and 60 feet in length, and they can weigh an impressive 54-71 tons. Their V-shaped blow, 200-300 baleen plates on each side and broad tail fluke are among their most significant and distinctive characteristics; however, the animal’s most distinctive trait is definitely represented by its callosities found primarily on its head.

The callosities often appear white due to the fact that they play host to large colonies of cyamids. There are three distinctive species of cyamids that live in symbiosis with right whales. These are Cyamis ovalis, Cyamis gracilis, and Cyamis erraticus. The latter is, in fact orange, and it can be found mainly in the wounds of right whales or feeding off the skin of very young specimens. The callosities are essentially patches of keratinized, thickened skin, that serve as a habitat for one or more of these species. The small crustaceans, also known as whale lice, are unable to swim or survive on their own, and they thrive by being transferred from one right whale to another through direct contact.

The symbiosis between the two species is not yet fully understood by marine biologists, however, it is known that the cyamids thrive off of the callosities of the right whales, because it serves as their habitat and food source. As for the actual effect or benefit that the symbiosis has on the individual whales, there are several theories. One is that it helps with mating. It is known that the callosities are congenital and that males of the species have higher a concentration. Also it was observed that some males have a habit of scratching each other with their callosities, which leads some researchers to speculate they play a role in determining which one is the more capable partner for a female. It is currently believed that the symbiosis is closer to commensalism, which means the cyamids benefit from the right whales’ callosities without causing any significant harm.

Blane Perun

Diver - Photographer - Traveler

Whale in Ocean