Cabinet of Curiosities: the walking catfish (Clarias batrachus)

Our new entry to the BioFresh Cabinet of Freshwater Curiosities is the remarkably destructive walking catfish.

Source: eol.org. © CAFS

It breathes air, eats practically anything, and “walks” using its pectoral fins, wriggling along as it searches for water. It’s the walking catfish, and its bizarre lifestyle makes it both fascinating and disastrous for freshwater ecosystems.

A native to southeastern Asia, the catfish has been introduced around the globe, including the UK and the US, where in Florida it has been recorded coming up from sewers in schools of 30 fish and going for a waddle down the street. According to George Monbiot, who’s included the fish in his book Feral: Searching for Enchantment on the Edges of Rewilding, it eats “anything that moves,” and it’s especially dangerous because it can walk to isolated pools that other invaders can’t reach. It poses a particular threat to fish farms, eating its way through millions in valuable stock. The catfish spread rapidly through Florida in the 1960s and 70s, due in part to releases and escapes from aquariums, and it is now banned by several countries, although it can sometimes still be found in pet stores. Potential owners are warned to keep the walking catfish in a secure aquarium, so that it doesn’t just squirm away. Check it out among the other amazing creatures in Biofresh’s Cabinet of Freshwater Curiosities!