This is why there are always large schools of fish swimming alongside sharks, even though they could be eaten at any moment.
Researchers have recently discovered that various fish species use sharks as… “brushes” in a fascinating form of symbiosis.
A school of fish swimming next to a shark in a graphic simulation. (Photo: UMiamiRSMAS)
The method they employ involves continuously bumping against the scaly body of the marine predator to remove parasites and other debris. “This phenomenon seems to be the only scenario in nature where prey actively seeks out and rubs against a predator”, said Lacey Williams, a researcher at the University of Miami.
Along with her colleagues, Williams first observed this behavior while collecting data on great white sharks (Carcharodon carcharias) in Plettenberg Bay, South Africa.
The researchers then compiled image data, videos, and reports from witnesses to conclude that up to 12 different fish species and 8 shark species exhibit a similar “symbiotic” behavior.
Professor Neil Hammerschlag at the University of Miami explains that shark skin is covered by tiny, tooth-like scales known as dermal denticles.
These scales create a rough surface for sharks, playing a crucial role in removing parasites or skin irritants from other fish species.
“This helps improve the health and fitness of many fish species. At the same time, it also provides sharks with a readily available food source”, Professor Hammerschlag stated.
