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.
This helps the eels (Muraena retifera) to be deadly hunters, despite the fact that, unlike many other predatory fish, they cannot generate strong suction forces inside the mouth cavity to capture a meal. Zoologists had previously been puzzled as to how moray eels, which live on coral reefs and rocky shorelines all over the world, keep hold of their prey long enough to swallow it.