On her deep-sea dives, wildlife biologist Angela Ziltener of the College of Zurich normally found Indo-Pacific bottlenosed dolphins performing some thing intriguing. The dolphins (Tursiops aduncus) would line up to consider turns brushing their bodies against corals or sea sponges lining the seafloor. Right after more than a 10 years as an “adopted” member of the pod — a position that allow Ziltener get up near with no disturbing the animals — she and her crew may perhaps have figured out why the animals behave this way: The dolphins might use corals and sea sponges as their own non-public pharmacies.
The invertebrates make antibacterial compounds — as effectively as many others with antioxidant or hormonal qualities — that are likely released into the waters of the Northern Purple Sea when dolphins make get hold of, Ziltener and colleagues report May possibly 19 in iScience. So the rubbing could aid dolphins retain healthy skin.
Ziltener captured video clip demonstrating users of the pod applying corals as if they had been a bath brush, swimming as a result of to rub numerous areas of their bodies. Oftentimes it is a tranquil social gathering. “It’s not like they are combating each and every other for the turn,” Ziltener states. “No, they wait around and then they go by means of.” Other occasions, an unique dolphin will get there at a patch of coral on its individual.
But the dolphins won’t buff their bodies from just any corals, Ziltener states. They are picky, primarily rubbing up in opposition to gorgonian corals (Rumphella aggregata) and leather corals (Sarcophyton sp.), as effectively as a type of sea sponge (Ircinia sp.).
Ziltener and colleagues analyzed 1-centimeter slices taken from wild corals and sponges. The group identified 17 compounds all round, together with 10 with antibacterial or antimicrobial action. It’s doable that as the dolphins swim via the corals, the compounds help protect the animals from skin irritations or infections, states coauthor Gertrud Morlock, an analytical chemist at Justus Liebig College Giessen in Germany.
Other animals, together with chimpanzees, can self-medicate (SN: 11/3/90). Maritime biologist Jeremy Kiszka of Florida Worldwide College in Miami says the new analyze convinces him that the dolphins are utilizing corals and sea sponges for that goal. But, he suggests, more experiments are essential to prove the hyperlink. Lab exams, for instance, could support identify the varieties of microbes that the compounds may possibly get the job done towards.
Ziltener agrees there is much more to be accomplished. For occasion, it is also possible that in addition to avoidance, dolphins use corals and sea sponges to address energetic pores and skin bacterial infections, she says, but the staff has nonetheless to see evidence of a coral cure. Subsequent up however, Ziltener claims, is figuring out no matter if dolphins favor to rub specific physique elements on unique corals in such an “underwater spa.”
