Catfish filmed climbing cave wall in Ecuador

Scientists have filmed a catfish performing the seemingly impossible feat of scaling the wall of a cave to lick food from its roof.

The scientists were trying to document the different types of wildlife in the cave complex, in Ecuador, when they were stunned to see several catfish trying to climb up a near vertical flowstone waterfall.

The scientists identified the fish as a species of armoured catfish called Loricariidae, BBC News reports.

The fish feed mainly on algae using their sucker-shaped mouths, which they use to cling onto rocks and trees in fast-flowing water.

According to a paper published in Subterranean Biology, this is the first time scientists have observed this species of fish climbing up a cave wall.

"It's not too surprising to find another catfish that climbs rocks. What is surprising is the environment that they are doing it in," said Geoff Hoese, who led the study.

"We may be watching a small but significant evolutionary step as a species moves from one niche to another."

Mr Hoese said he needs to return to the region, near Tena in the Napo District of Ecuador, to determine whether these fish have simply got lost or if they have they evolved to deal with a new situation.