The findings will be published tomorrow in the journal Nature.
Using high-speed video, Mehta and study co-author Peter Wainwright observed moray eels eating squid and noticed that the eels used a very unique set of secondary, or pharyngeal, jaws to devour their prey.
While most fish use these secondary jaws to manipulate prey and help in swallowing, Mehta and Wainwright noticed an important distinction in the moray's jaws. (Related news: "Jaws, Teeth of Earliest Bony Fish Discovered" [August 1, 2007].)
"The pharyngeal jaws in their throat exhibit a very different architecture from the jaws of other bony fishes," Mehta said. "[They] look like a fancy pair of forceps with large, sharp recurved teeth."
And unlike most pharyngeal jaws, which have a limited range of motion, the moray's inner mandibles have elongated muscles that allow for extreme mobility.
This unique feature allows the eels to protrude their secondary jaws forward from their throats and into their mouths, where they grasp prey and guide it toward the esophagus.
This dual-jaw system allows morays to maintain a grip on their food at all times, Mehta said.
Mark Westneat is the curator of zoology at the Field Museum of Natural History in Chicago.
"That's what's fascinating about this discovery," he said. "Lots of fish have pharyngeal jaws, but they tend to be hard grinding plates or jaws with little teeth that don't move much.
"What's unusual about the morays' jaws is their ability to drag prey from the mouth back into the throat."
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