New evidence of grey reef sharks (Carcharhinus amblyrhynchos) displaying chafing behaviors on whale shark (Rhincodon typus) individuals in the Maldives

Abstract

Sharks rubbing against ocean floor or rocks are common events in marine environments, while instances of interspecific shark chafing behavior have been observed much less frequently. This behavior has garnered scientific interest in recent years and usually involves a smaller shark rubbing against a larger species, utilizing dermal denticles to rid itself of parasites or dead skin cells. Despite the costs and benefits of this behavior being not yet fully understood, we report new evidence of grey reef sharks (Carcharhinus amblyrhynchos Bleeker, 1856) engaging in chafing behavior against whale shark (Rhincodon typus Smith, 1828) in the Maldives. This behavior suggests that grey reef sharks may engage in chasing behavior for cleaning purposes or take advantage of larger sharks as an anti-predation tactic. These records contribute to shed light on previously unexplored aspects of elasmobranch interspecies interactions and highlight the need for further research into this topic. The prevalence of such behavior across different regions suggests its potential significance in the ecological dynamics of shark population.