Moray eel can bite you twice

Remember the science-fiction monster with a jaw within a jaw that terrorized Sigourney Weaver in the “Alien” films? Well, it turns out a similar double-jawed creature actually exists: The moray eel has a second set of jaws located in its throat that snaps forward to grab prey and pull it down the eel’s digestive system.

“This is really an amazing innovation for feeding behavior,” said Rita S. Mehta of the University of California at Davis, who documented the second jaws last week in the journal Nature.

Using a high-speed digital camera, X-rays and other imaging technology, Mehta and a colleague captured the action of the second jaws.

Most fish feed by expanding their mouths and sucking in water with the food or grabbing it with their jaws.

Because of their anatomy, moray eels have little ability to create suction through their mouths, Mehta found. Instead, they first grab the food with their strong outer jaws. Next, the inner “pharyngeal” jaws, equipped with large, curved teeth, reach forward and seize the prey, pulling it back to be swallowed.