Great white shark with bite and scar inflicted by a cookiecutter shark. The arrow shows the scar from a healed gash.
The bites, recently documented in the journal Pacific Science, are like the ultimate sushi. Lone cookiecutters sneak up on their great white victims before taking a big bite. The sneaky predators rotate their bodies, allowing them to remove plugs of flesh. This leaves the great white victim grossly injured, but still alive.
The attack is quite a feat, considering that cookiecutter sharks are just one-tenth the size of great whites.
“In most cases, these little sharks will eat little prey, but with cookiecutter sharks, you have this unique situation of a small shark that will target animals much, much larger than itself, up to 10 times their own size, and that’s pretty unique in the animal kingdom — it’s a very active foraging process,” co-author Yannis Papastamatiou, a marine biologist in the division of ichthyology at the Florida Museum of Natural History on the UF campus, said in a press release.
For the study, the researchers analyzed a bite wound near a great white shark’s mouth. The great white shark was photographed by a diver in a shark cage near Guadalupe Island in the Pacific Ocean.
Cookiecutters inhabit deep tropical waters. Their bites have been found on many animals, including tuna, whales, dolphins, swordfish, elephant seals and even humans.
“When biologists first started noticing the bites on the pelagic fishes and whales, they thought it might be a viral infection because they didn’t know any animal that could bite and leave such a smooth wound,” Papastamatiou said. “And it’s not only animals — they’ve taken chunks of plastic out of submarines and underwater oceanographic equipment, so it’s pretty amazing what they can do.”
This “talent” is made possible by the cookiecutter’s unique teeth. Unlike the teeth of other sharks, those of cookiecutter sharks are connected at the bottom in the lower jaw, allowing them to scoop out the flesh of their victims like a living melon baller.
These sharks have the largest teeth of any shark in relation to the size of their jaws. Cookiecutters are also bioluminescent, meaning they produce their own light on parts of their bodies. Their hunting tactic is to hide and surprise larger fish, taking bites before quickly leaving the scene.
“It’s a very mysterious little fish in a lot of ways and that’s mainly because it’s so difficult to study — you hardly ever see them alive,” Papastamatiou said. “We really have to study cookiecutter sharks based on either dead specimens or by their bite wounds on prey.”
John McKosker, a senior scientist at the California Academy of Sciences, added, “The public thinks that white sharks, based on the film ‘Jaws,’ are the ultimate predator, whereas even white sharks are preyed upon in this case, by a shark no longer than your forearm.”
(Image: Mauricio Hoyos Padilla et al/Pacific Science)