Wdon’t you like peeling in the bathtub? Dolphins certainly do: they are known for being smart, playful and tangible animals and like to rub against rough surfaces, nap in coral beds and soak on mushrooms like guests in underwater spas.
However, dolphins can enjoy more than just relaxation and free time from peeling in the bathtub. A study published today suggests that bottlenose dolphins can treat their skin conditions themselves with corals, contributing to growing research into their previously unexplored healing properties.
“It’s very intense,” said Angela Ziltener, one of the study’s lead authors, about the behavior of dolphins with specific corals. “They’re not just going through that.” [the coral] “They go up, they go back down again and they rub their belly, abdomen and back.”
Dolphins have strong, smooth and resistant skin, but can be prone to skin diseases such as yeast and bacterial infections, scars or tattoo-like lesions caused by smallpox viral infections. These ailments seem to be exacerbated by global warming.
Ziltener, a wildlife biologist at the University of Zurich in Switzerland, and her team researched a community of 360 Indo-Pacific bottlenose dolphins (Tursiops aduncus) in the northern Red Sea since 2009. They observed that dolphins often lined up from nose to tail to rub against corals as soon as they woke up and just before going to bed, as if taking a shower all day. In addition to mechanical friction, the dolphins also caused the corals to release polyp mucus.
The team also noticed that the dolphins had returned to the same species of coral, and seemed to be carefully choosing which parts of their bodies to rub. They performed laboratory tests on 48 samples of corals, fungi and coral mucus “selected” by dolphins, including Gorgonian corals. Rumpella aggregataleather coral Sarcophyton sp. and sponge Ircinia sp.
The results published in iScience revealed at least 17 different bioactive metabolites with estrogen-like antibacterial, antioxidant and hormonal properties, all of which could be useful in skin treatment.
These compounds are not commonly used in human or animal antibiotics, but growing research shows that some corals and fungi have medicinal properties, including antimicrobials.
“Such metabolites are useful if you have an infection,” said Gertrud Morlock, an analytical chemist at Justus Liebig University in Giessen, Germany, and lead author of the study. “If dolphins have a skin infection, these compounds may have something of healing properties.”
“When you think about it, they have no choice.” If they have a skin problem, what can they do? ”
The authors note that further research is needed to show which healing properties of coral dolphins need to treat a given disease and whether these properties have a measurable positive impact on cetacean health.
Learning more about the dolphin social network and demographic group could help. Monitoring the individual dolphins that exhibit this behavior and whether they have fewer skin diseases or reduced mortality compared to the rest of the group would reinforce this argument, says Sarah Powell, a former marine biologist who studies how dolphins transmit their skin diseases. but was not involved in the study.
Past research has shown that dolphins like to use coral sponges as foraging tools. “It doesn’t seem to me to be that the dolphins use corals and other plants in their environment for other purposes,” Powell said.
Stephanie Venn-Watson, a marine biologist who studies the health and longevity of dolphins and also did not participate in the research, said: dolphins are the use of corals for medicinal purposes. ”
The next step to prove the connection would be to show that the corals of ignored dolphins lack the same healing properties, she said. “This is a nice, scientifically motivated scratch itch.”