Whereas rubbing up in opposition to a shark seems like a dangerous transfer when you’re a fish, a collaborative analysis workforce led by the College of Miami (UM) Shark Analysis and Conservation Program on the Rosenstiel Faculty of Marine and Atmospheric Science discovered that this conduct is frequent, widespread, and will play a beforehand unappreciated vital ecological position for aquatic animals.
Though situations of fish chaffing in opposition to sharks has beforehand been noticed, this research finds this cross-species conduct to be extra pervasive than beforehand understood. The analysis workforce examined underwater photographs, video, drone footage, and witness reviews to search out 47 situations of fish rubbing themselves in opposition to a shark’s pores and skin. The chafing occasions, which had been documented in 13 places all over the world, diverse in length from eight seconds to over 5 minutes. They recorded 12 fin fish chafing in opposition to eight completely different species of shark, together with nice whites. The workforce even documented silky sharks chafing on the pinnacle of a whale shark. The variety of fish chafing in opposition to sharks ranged from one to over 100 people at a time.
“Whereas chafing has been effectively documented between fish and inanimate objects, akin to sand or rocky substrate, this shark-chaffing phenomenon seems to be the one situation in nature the place prey actively search out and rubs up in opposition to a predator,” mentioned UM Rosenstiel Faculty graduate scholar Lacey Williams, who co-led the research with fellow graduate scholar Alexandra Anstett.
Utilizing aerial drone surveys in Plettenberg Bay, South Africa, Williams and Anstett documented 25 occurrences of a leervis fish turning to chafe in opposition to a passing nice white shark.
“Whereas we do not precisely know why it is taking place, we’ve got a couple of theories. Shark pores and skin is roofed in small tooth-like scales known as dermal denticles, which give a tough sandpaper floor for the chafing fish,” mentioned UM Rosenstiel Faculty analysis affiliate professor and research co-author Neil Hammerschlag. “We suspect that chafing in opposition to shark pores and skin may play an important position within the elimination of parasites or different pores and skin irritants, thus enhancing fish well being and health.”
Supplies offered by College of Miami Rosenstiel Faculty of Marine & Atmospheric Science. Authentic written by Diana Udel. Be aware: Content material could also be edited for fashion and size.