Moray eels' hidden jaws pack second bite

By Julie Steenhuysen

CHICAGO (Reuters) - Moray eels, those snake-like predators that lurk in coral reefs, use a second set of jaws to pull prey back into their throats with deadly efficiency, researchers said on Wednesday.

Biologists have known for some time that moray eels have a second set of jaws, known as pharyngeal jaws, as do many other bony fish. But until now, biologists had never seen them put to such unique use.

"They spotted this outrageous behavior of the pharyngeal jaw thrusting way forward into the mouth, which was not suspected before," said Mark Westneat, who studies feeding mechanisms of coral reef fishes at the Field Museum of Natural History in Chicago.

"The surprise and interest was the extent of the movement, and how it grasped the prey and yanked it back into the throat," Westneat, who wrote a commentary on the findings, said in a telephone interview.

"It's one of these great 'Oh wow' stories in basic biology."

Rita Mehta and colleagues at the University of California Davis discovered the moray's special feeding ability through high-speed digital cameras, that captured the second jaw as it jutted forward while feeding.

Mehta, whose study appears in the journal Nature, said the jaws allow the eels to swallow large prey.

Mehta had set out to understand the purpose of this second set of jaws in moray eels, a diverse group of some 200 species.