When you picture sharks and rays, how do you think of them? Chances are, you are imaging them gliding through the water effortlessly, or chasing through the blue after prey. Or perhaps you’re picturing them as they display a behavior that seems quite out of place for an animal that lives completely in an aquatic environment: breaching.
The sight of a shark or ray leaping out of the water, soaring through the air, and splashing back down is an unforgettable experience. Known as breaching, it’s a spectacle that has captured the imagination of scientists and ocean enthusiasts alike. Once thought to be a behavior that was limited to fast-swimming, predatory sharks, it has been also observed in slower, plankton-feeding species and many types of rays. This raises the question: why do they do it?
Led by Dr. Peter Klimley of the Department of Wildlife, Fish and Conservation Biology, University California, a new study has reviewed all the reasons why a shark or ray might possibly want to ‘fly.’ Their research has identified breaching behavior across a wide range of species in both the shark and ray families. Among sharks, breaching is observed in the Alopiidae (thresher sharks), Carcharhinidae (requiem sharks), Cetorhinidae (basking sharks), and Lamnidae (mackerel sharks) families, while among rays, the behavior is seen in the Mobulidae (manta rays), Aetobatidae (eagle rays), Myliobatidae (another family of eagle rays), Rhinopteridae (cownose rays), and Dasyatidae (stingrays) families. The breaching itself can vary – some exhibit a full leap out of the water while others only execute a partial lunge, where the animal doesn’t completely clear the surface but still propels itself upward with significant force. The diversity of species that partake in the act itself – and the different types of breaching – suggests that this behavior is not only widespread but also serves multiple functions, depending on the species and the context.
One of the most commonly cited reasons? The removal of parasites. Sharks and rays, like many marine animals, can be plagued by external parasites that attach to their skin. The sudden change in pressure and the impact with the water surface might help to dislodge these unwelcome hitchhikers, providing relief from the constant irritation they most likely cause. Similarly, breaching might help these animals clear their gill rakers – structures that filter out food particles from the water – of debris or parasites. In a similar vein, breaching might play a role in the expulsion of feces or internal parasites. The force of hitting the water’s surface could help these animals clear their digestive tracts more effectively.
Breaching also seems to be linked to social behaviors, such as courtship. During mating seasons, these dramatic leaps could serve as displays to attract potential mates. The noise and splash created by a breaching shark or ray might catch the attention of a nearby individual, signaling readiness to mate. (One just hopes it’s an individual of the opposite sex for this to work!) The review found that there is the possibility that breaching is involved in birthing. While this is still a relatively unexplored area, the team suggests that the act of breaching could help in the birthing process, either by physically assisting in the expulsion of pups or by signaling the onset of labor to other sharks or rays.
Conversely, breaching may also be a means of evasion. When a shark or ray finds itself threatened by a predator, a sudden breach could serve as a quick escape tactic. This would be especially useful in the open ocean, where there are few places to hide. It could also be a method of repelling competitors, with the loud splash signaling dominance or territoriality.
But perhaps the most famous reason for breaching is what has been captured and broadcasted worldwide: breaching. Who hasn’t seen a great white shark leaping out of the murky water to give chase to an unsuspecting seal off South Africa? Yes, the element of surprise and the force of this breaching event can lead to the capture of their prey. In other cases, breaching might help concentrate or stun prey, making it easier to catch; take the thresher shark, which uses its long tail to whip schools of fish into a tighter formation before breaching to strike.
The authors point out that thanks to recent advancements in technology have significantly enhanced our understanding of breaching behavior outside of traditional observations. Animal-borne data loggers, capable of recording everything from depth to acceleration, have provided unprecedented insights into the conditions under which breaching occurs. High-resolution digital photography and observations from aerial or underwater drones have also allowed scientists to capture breaching events in stunning detail, revealing not just when and where they breach, but also the environmental conditions and potential triggers for this behavior.
As researchers continue to collect and analyze data, the picture of why these incredible animals breach is becoming clearer. While many questions remain, the evidence points to a multifaceted behavior with roots in survival, reproduction, and communication. Each breach, whether a dramatic leap into the air or a more subdued lunge, gives us a glimpse into the intricate lives these predators lead beneath the waves.
