Apparently this is how they exfoliate dead skin cells and grime off their bodies.

Humpback whales also sometimes need a spa day. This is evidenced by the new photos, which show how different whales rub and roll over the sea floor. Researchers believe this is how these majestic animals take care of their bodies, they write in the journal Marine biodiversity records.

More about humpback whales
The humpback whale (Megaptera novaeangliae) is a marine mammal subspecies of baleen whales. Adult humpback whales can grow up to 12 to 16 meters in length and weigh between 25 to 30 tons. It is distinguished from other fin whales by its long pectoral fins, stocky body, and tubercles on the mouth and lower jaw. Humpback whales are famous for their singing. For example, male humpback whales sing cheerfully during the mating season. Their songs are of a low frequency, like the noise made by large freight and passenger ships. Humpback whales have been hunted intensively for many years. In 1966 this ended. By the way, this was not a superfluous luxury: there were only 1,400 specimens left in the North Pacific at that time. Since then, the numbers have increased steadily. It is estimated that about 20,000 humpback whales are now swimming in the Pacific Ocean again.

Pictures can be viewed below. These were made using tags affixed to a number of humpback whales migrating south. These tags, which look like suction cups, have been placed on the whales’ backs and act as advanced gauges, complete with camera, GPS, and other sensors.

In the pictures you can ride on the back of a whale and see for yourself how it rolls over the seabed. Homogeneous seems to be doing the same thing in the background. “The whales move forward slowly, their head touching the sand first,” says researcher Olaf Meinecke. “Then they roll to one side or complete a full side roll.”

cleaning
Why do whales exhibit this strange behavior? The sea floor is surrounded by fine sand and rubble. And by rolling there, they take care of their skin. You can compare it to an in-shower body scrub. In fact, whales “exfoliate” dead skin cells and flakes from their bodies in this way. “We think the whales use sand to remove parasites from their bodies,” Meinecke said.

barnacles
This is also necessary. Barnacles are crustaceans, closely related to crabs and shrimp. They attach themselves to a variety of surfaces, including ship hulls, turtle shells, and whale skin. However, this slows it down, as it gives additional resistance in the water. To prevent overgrowth, they must regularly get rid of these barnacles. By the way, not every place is suitable for this. “They choose very specific territories,” says Meynecke.

skin bacteria
In addition to the barnacles, whole pieces of skin fly away during the “spa turn”. And this is no accident. In addition to barnacles, whales harbor several communities of skin bacteria. And they are not always peaceful. “Some pose a threat to open wounds, for example if bacteria multiply,” explains Meinecke. Removing excess skin is probably necessary to maintain a healthy skin bacterial community. Some barnacles and dander can get rid of them by jumping out of the water, but not all of them.”

leather
In the images, the researchers saw how whales lost pieces of skin during sanding. Then that skin gets another purpose, because the different fish are enjoying it again. And so the circle was completed again.

relaxation
Incidentally, the researchers suspect that the observed behavior not only serves a beneficial purpose. It may also be a social activity. Meynecke notes that “behavior after mating, competition, or other forms of socialization”. This means that it may also be associated with play or relaxation.

Thanks to the images, biologists are getting a better view of the life of humpback whales, which seem to have devised a clever way to keep their bodies healthy. By the way, whales are not the only marine mammals that take care of their skin. Last year, researchers noticed dolphins rubbing against coral reefs. This also appears to be an effective treatment against microbial infections.