New research suggests that dolphins may self-medicate for their skin conditions, adding to evidence for the medicinal properties of some corals and sponges.
Who doesn’t love a bath scrub? Dolphins definitely do: they’re known to be intelligent, playful, and tactile animals, and they like to rub against rough surfaces, nap on coral beds, and soak in sponges as guests at an underwater spa.
However, dolphins can get more from their bathing scrubs than just relaxation and leisure. A study published today suggests that bottlenose dolphins may be able to self-medicate for their skin ailments with the help of corals, adding to growing research into their previously unexplored medicinal properties.
“It’s very intense,” Angela Ziltener, one of the study’s lead authors, said of the dolphins’ behavior with particular corals. “They not only go through [el coral]: they go up, come back down and rub their belly, ventral area and back”.
Dolphins have thick, smooth, and tough skin, but can be prone to skin conditions such as bacterial and fungal infections, scarring, or tattoo-like lesions caused by viral infections of smallpox. These ailments appear to be exacerbated by global warming.
A study on dolphins and corals
Ziltener, a wildlife biologist at the University of Zurich, Switzerland, and her team have been surveying a community of 360 Indo-Pacific bottlenose dolphins ( Tursiops aduncus ) in the northern Red Sea since 2009. They observed that cetaceans often queued up to rub against corals as soon as they woke up and just before going to sleep, as if they were showering to start the day. In addition to mechanical rubbing, the dolphins also caused the corals to release polyp mucus.
The team also noticed that the dolphins returned to the same coral species and seemed to be finicky about choosing which parts of their body to rub. They did laboratory tests on 48 samples of coralssponges and coral mucus “chosen” by dolphins, including gorgonian coral Rumphella aggregate leather coral Sarcophyton sp. and the sponge Ircinia sp.
The results, published in the journal iScience, revealed at least 17 different bioactive metabolites with antibacterial, antioxidant and estrogen-like hormonal properties, all of which could be useful in skin treatments.
The compounds are not commonly used in human or animal antibiotics, but an expanding body of research shows that some corals and sponges have medicinal, even antimicrobial, properties.
“Such metabolites are helpful if you have an infection,” said Gertrud Morlock, an analytical chemist at Justus Liebig University Giessen in Germany, and lead author of the study. “If the dolphins have a skin infection, these compounds could have something like a healing property.
“But if you think about it, they don’t have any other options. If they have a problem with their skin, what can they do?
Corals with medicinal properties
The authors note that more research is needed to show what medicinal properties of coral are needed by dolphins to treat certain ailments, and whether these properties have a measurable positive impact on cetacean health.
Learning more about the dolphin’s social network and demographics could help with this. Tracking individual dolphins displaying the behavior and seeing if they have fewer skin diseases or lower mortality compared to the rest of the group would strengthen this argument, according to Sarah Powell, a former marine biologist who studies how dolphins transmit their diseases. of the skin, but who was not involved in this study.
Previous investigations have shown that dolphins like to use coral sponges as feeding tools. “I don’t think it’s that big of a scope for dolphins to use corals and other plants in their environment for other purposes,” Powell said.
Stephanie Venn-Watson, a marine biologist who studies dolphin health and longevity and was also not involved in the research, said: “Since dolphins are inherently playful and tactile animals who love to rub, it’s hard to be sure. that are using the corals for medicinal purposes”.
The next step in proving the link would be to show that corals ignored by dolphins lack the same medicinal properties, he said. “This is a good science-driven itch to scratch.”
By Sophia Quaglia. Item in English