Clarias batrachus (Walking Catfish) is a freshwater fish native to Southeast Asia, from eastern India, Bangladesh, and Sri Lanka to the Laos, the Malay Peninsula, and western Indonesia This catfish inhabits rivers, lakes, canals, swamps, temporary ponds, and ditches.. It is capable of breathing air and moving short distances overland, or of aestivating in mud when a pool dries up, so it is tolerant of poorly oxygenated water, and can colonize seasonal, temporary pools, and rice paddies.. It has been introduced to Sulawesi (Western Indonesia), the Philippines, Taiwan, Guam, and Papua New Guinea. This fish is widely sold as an aquarium fish, often as albinos. and have been reported from 7 states. However, it is established only in central and southern Florida.. It can tolerate deoxygenated water, and can colonize seasonal, temporary pools, and rice paddies. It has been introduced to Sulawesi (Western Indonesia), the Philippines, Taiwan, and Guam, Clarias batrachus showed mortality at 10 C². and has been collected at salinities up to 18 PSU.
Clarias batrachus was first brought to Florida in 1965 by a tropical fish-rearing operation, which reared them in outdoor pods near Deerfield Beach, Florida. The fish escaped and dispersed through southern Florida's many canals. It is established on the southern half of the Florida peninsula, from tributaries of the Indian River Lagoon and Tampa Bay (in 1979) to Florida Bay by 1987. This fish has been collected in the Intracoastal Waterway at a salinity of 18 PSU ,so has some ability to disperse through brackish water. Walking Catfish have been caught in California, Nevada, Arizona, Connecticut, Massachusetts, and Georgia, but have not become established outside Florida. Observations on a Florida pond suggest that native fishes has a bigger predatory impact than Walking Catfish.