Eels Escape the Stomach of a Predatory Fish

Japanese eels (Anguilla japonica) have the ability to escape the stomach of freshwater predatory fish (Odontobutis obscura) by swimming backwards through the esophagus and gills. Contrary to expectations, 9 out of 32 young eels successfully made their escape, before succumbing to the acidic stomach environment.

The Japanese eel population is declining, and they are currently listed as Endangered on the Red List. This study, published in the journal 'Current Biology', injected contrast agents into the eels to track their movements.

This is the first study to provide video evidence of the eels escaping the stomach of their predators. The elongated shape of the eels may have aided their escape, and further research will explore this phenomenon with other eel species and fish with similar body shapes.

The findings reveal an impressive and unique defense tactic employed by Japanese eels.