Researchers have discovered that bottlenose dolphins in the Red Sea rub against corals and sponges that have medicinal properties.
Bottlenose dolphins appear to repair skin and stay healthy by repeatedly rubbing up against corals that have natural medicinal properties, according to new research.
Corals and sponges used by the dolphins have been found to contain 17 bioactive compounds, with different properties, such as antibacterial, antioxidative or hormonal attributes.
Lead author Gertrud Morlock of a paper just published in the journal Cell and her team analysed samples of coral used by the dolphins and their discovery of these compounds led the researchers to deduce that the mucus in the corals and sponges helps regulate dolphin skin and treat infections.
It was when co-author Angela Ziltener, who is both a biologist and a diver, and her team first observed dolphins rubbing along the corals off the coast of Egypt in 2009, they also noticed that the dolphins appeared to be selective about which coral they rubbed against. The researchers wanted to understand why.
It was apparent that the dolphins knew exactly which coral they wanted to use,” Ziltener said in a statement. “I thought, ‘There must be a reason.'"
The behaviour was not random: The dolphins rubbed their heads on some corals, scraped their bellies on others, and avoided some species altogether.
It turned out that by repeatedly rubbing against the corals, the dolphins agitated the little polyps and caused them to secrete mucus. Not only were they selecting specific corals, but as they rubbed, mucus coatings puffed off the corals and sponges, clouding the water and colouring the dolphins’ skin. The team collected samples of the corals to turn over to Morlock, who is an analytical chemist, for analysis.