Divers work with a model European catfish in the Great Lake at Ostersund in Sweden. Large catfish live in many rivers throughout the world, where they are important scavengers.
The largest on record is the Mekong giant catfish, which has reached recorded sizes up to 10.5 feet (3.2 meters) and 660 pounds (300 kilograms). Once distributed across several countries in Southeast Asia, the Mekong giant catfish is now critically endangered, thanks to habitat disruption. Not much is known about the world’s biggest freshwater fish, although conservation efforts are underway.
Big catfish are rarely considered dangerous to people. The Mekong species can live to be more than 60 years old.
Photograph by John Robertson, Alamy