on gorgonians (Rumphella aggregata) in Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Hurghada, Northern Red Sea, Egypt
Several hypotheses have been proposed concerning the functional role of self-rubbing or object rubbing in odontocetes. These include hygiene (e.g ectoparasite removal), sensual pleasure, play and socializing activity. Systematic observations around the Hurghada area, Northern Egyptian Red Sea, revealed that Indo-Pacific bottlenose dolphins (Tursiops aduncus) regularly rubbed on gorgonians (Rumphella sp.). Event sampling from video recordings obtained while scuba diving showed dolphins approaching gorgonians and then rubbing their body into it while rolling on the side, back and belly. This behaviour is often repeated and individuals queue up behind each other to wait for their next Approach.
We hypothesize that gorgonian-rubbing (hereafter gorgoning) represents prophylactic or even therapeutic self-medication. Previous studies show that gorgonians possess antibacterial and antifungal properties. In the upcoming months we aim to analyze Rumphella sp. for its biologically active compounds. Furthermore, the group- and age structure of gorgoning dolphins will be examined. Further work is needed to confirm whether gorgoning qualifies as the first documented case of zoopharmacognosy in any cetacean.