Great white sharks may be the world’s most feared predator, but when it comes to biting strength the bull shark is at the top of the list. According to a study published in Zoology, adult bull sharks have the most powerful bite in relation to body size and can chomp with more than 1,300 pounds of force.

The study involved 13 predatory shark species, including the great white, and results were based on the examination of jaws and jaw muscles of dissected specimens.

“What this study shows is that pound per pound bull sharks have the largest bite force value among all studied sharks,” Maria Habeggar, a University of South Florida researcher, told BBC Nature. “Bull sharks can bite harder than a great white shark and great hammerhead.”

It’s not clear why bull sharks possess such crushing bite strength. One theory is that it may help give them advantage over competing species. Also, possessing a powerful bite may help them crack turtle shells and/or help them cling to other prey in murky waters.

“In a lower visibility environment catching prey may be more difficult than in open water,” said Habeggar, whose study was conducted with colleagues in the U.S. and Germany. “So once you get a prey between your jaws, securing it is crucial to not lose your meal.”

Bull sharks are found in warm, shallow waters throughout the world, and have been known to swim in brackish water, and even far into rivers. They can measure to about 11 feet and weigh up to 500 pounds. White sharks, by comparison, can measure to 18 feet and weigh 5,000 pounds.

But bull sharks are notoriously aggressive and have been implicated in dozens of attacks on humans.

One of the most frightening examples of their aggressiveness was in May of 2008 off Zihuatanejo, Mexico, when three surfers were attacked in less than a month. Two of them bled to death and a third, Bruce Grimes, was bitten on the arm and managed to paddle shore and drive himself to the hospital.

Grimes said the shark was trying to bump him off the surfboard as he paddled toward the beach.

This spate of attacks was considered an anomaly, but surfers in the area remained skittish for months.

–Bull Shark image is from Wikipedia, with credit to Terry Goss