When Barracudas Attack: Swift and Sharp

Jan. 25, 2008 -- The great barracuda deserves its fearsome reputation, suggests a new study on its predatory ways. The toothy fish tackles large prey, the study's authors report, by impaling its victim with sharp fangs and then slicing it in half, scissor-style.

The technique may explain why barracuda stomachs are often found to hold multiple "back-halves" of prey, since the force of the event often sends the front halves flying out of the barracuda's mouth.

"The barracuda is a lightning-fast predator," said Aaron Rice, a co-author of the study and a postdoctoral fellow in the Department of Neurobiology and Behavior at Cornell University.

"In literally thousandths of a second, once a prey fish is located, the barracuda performs a giant tail-beat to accelerate forward while the jaws are opening, then impacts with the prey fish moments later, closing the jaws on contact," Rice explained.

To determine what barracudas do next, Rice and colleagues Justin Grubich and Mark Westneat studied the anatomy of seven great barracudas across a large range of body sizes. They also captured barracuda biting with high-speed video that revealed the process frame by frame.

The findings are published in the current issue of Zoology.

Their conclusion? A barracuda bite is "like a combination between scissors and a steak knife," said Rice.

"Barracuda jaws work similar to scissors in that there are two opposable sharp edges, which quickly close and cut the food item from the top and bottom," he explained.

The tropical predator's teeth are unique among all other fishes, sharks, reptiles and mammals. In addition to having teeth embedded in the upper and lower jaws, barracudas have additional teeth on two sets of bone, called the palatine, inside its mouth.

The extra teeth allow the upper jaw to be used for grasping prey, while the lower jaw and palatine teeth do the actual cutting. Prominent, fang-like teeth protrude from the front of the upper and lower jaws, helping with impaling and grasping.