REMARKABLE new footage has revealed the miraculous escape young eels make after they’ve been swallowed alive by predator fish.
The X-ray video shows the “truly astonishing” route juveniles take to avoid impending doom.
Nine of 32 managed the great escape from a predator fish like the one above[/caption]
And it’s all via the hungry fish’s gills – but the way they pull it off is even more surprising.
While in the digestive tract, Japanese eels don’t push through head first.
They actually back their way out, inserting the tips of their tails through the esophagus and gills before pulling their heads free.
“We have discovered a unique defensive tactic of juvenile Japanese eels using an X-ray video system: they escape from the predator’s stomach by moving back up the digestive tract towards the gills after being captured by the predatory fish,” said Yuuki Kawabata from Nagasaki University in Japan.
“This study is the first to observe the behavioral patterns and escape processes of prey within the digestive tract of predators.”
Experts have been aware of eels escaping death this way, but it’s only now that they’ve understood how they do it.
Only when they got an X-ray video device involved were they able to see their clever stunt from beginning to end.
Eels were injected with a contrast agent that would make them show up in the footage.
It took the team a year to get enough clear evidence on video.
Their research found that all 32 captured eels had at least part of their bodies swallowed into the stomach of their fish predators.
After the eels were gobbled up, all but four tried to escape by going back through the digestive tract toward the esophagus and gills.
Some 13 managed to get their tails out the fish gill, and nine successfully made their great escape through the gills.
On average, it took the escaping eels about 56 seconds to break free.
“At the beginning of the experiment, we speculated that eels would escape directly from the predator’s mouth to the gill,” Kawabata added.
“However, contrary to our expectations, witnessing the eels’ desperate escape from the predator’s stomach to the gills was truly astonishing for us.”
The research was published in the Current Biology journal.
