Eels imitate Alien

Nature is remarkable. My college mentor, Don Jackson, is a comparative physiologist, and I learned so much from him about particular organism’s adaptations to extreme environments.This News feature from Nature is not about extreme environments, but discusses a unique adaptation of the moray eel. Apparently, the moray eel cannot generate high suction forces for swallowing its prey. To prevent the escape of its prey, a second set of “jaws” reside inside its mouth and hold its prey for swallowing.

clipped from www.nature.com Fearsome fish have protruding jaws in their throats to grab prey. Researchers studying one species of moray eels have uncovered a deadly secret that helps the snake-like fish to swallow their prey. Like the fearsome extraterrestrial from the sci-fi horror classic Alien, these real-life beasts have a second, extendable pair of jaws — encrusted with sharp teeth — that thrusts forward to ensnare hapless fish and shrimp. High-speed videos and X-ray photos (above) show how the second jaws, called pharyngeal jaws, lie in wait inside the throat, and then extend forwards into the mouth to grab prey that has been captured by the eel’s main teeth. The morsel is then drawn into the eel’s oesophagus. A moray eel’s second jaws lie in wait (top) before snapping out to help catch prey (bottom). Click here to watch a video.