How Moray Eels Swallow Prey

Moray eels developed a unique mechanism to swallow prey: they have a second set of jaws, called pharyngeal jaws, that can be launched out of its throat into its mouth. If this reminds you to the monster in the movie "Alien", you are right! Despite this, moray eels are friendly creatures and generally not aggressive to divers. Many other fish have also pharyngeal jaws. However, these are sitting in the throat and cannot be extended to the mouth. This is unique for moray eels.

In this picture you can see both jaws in a Spotted Moray (Gymnothorax moringa). The three large teeth in the center belong to the pharyngeal jaws. After catching the prey this jaw is retracted deep into the throat (with the prey, of course). On the right, you find an illustration from Wikipedia (originally NSF, see links below) showing the second jaw in the oral cavity (bottom) and retracted (top).

	Source: Wikipedia, NSF

 

Links:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06062.html: the original paper by R. Mehta and P. Wainwright in Nature 2007.
http://en.wikipedia.org/wiki/Pharyngeal_jaws: short Wikipedia article.
http://www.nsf.gov/news/news_images.jsp?cntn_id=109985&org=NSF: description of the NSF financed work leading to the discovery. Here you can find nice videos of moray eels eating fish and a piece of squid.