Walking Catfish

Scientific Name: Clarias batrachus
Identification: Walking catfish, which are scale-less, are typically a uniform shade of gray or gray-brown with many small white spots along their sides. The head is flat and wide and the body tapers to the tail. The eyes are very small and the mouth is broad with fleshy lips and numerous small pointed teeth in large bands on both the upper and lower jaw. There are four pairs of barbels, one pair each of maxillary and nasal barbels and two pairs of mandibal barbels. The fish has a lengthy dorsal and anal fin that each terminate in a lobe near the caudal fin. The pectoral fins, one on each side, have rigid spine-like elements. To move outside of water, the fish uses these "spines" and flexes its body back and forth to "walk". The walking catfish is easy to distinguish from many of the other North American catfish because it doesn't have an adipose fin.


In addition to the brown or gray-brown coloring noted above, albinos and calico morphs are also possible. However, these are uncommon in the wild. For example, in Florida the fish that escaped were albinos but today the albino is rare and descendants have generally reverted to the dominant, dark coloring.

The fish reach reproductive maturity at one year and grow up to 24 inches in their native range. However, in Florida they rarely exceed 14 inches.

Walking catfish possess a large accessory breathing organ which enables them to breath atmospheric oxygen. They are well known for their ability to "walk" on land for long distances, especially during or after rainfall.

Original Distribution: The walking catfish are a widely distributed species found across Southern Asia including Pakistan, Eastern India, Sri Lanka, Bangladesh, Myanmar, Thailand, Malaysia, Indonesia, Singapore, Borneo, Laos and the Philipines. It's hard to determine, though, to what extent this distribution comprises the native range. In Southeast Asian this fish in valued for food and it's probable that human activity is responsible for the presence of this species in parts of its current range.
Current Distribution: In addition to the locations listed above, the walking catfish has been found in the US. Specimens have been collected in multiple locations across California, the All American Canal in Arizona, widely separated bodies of water in Connecticut, the Flint River in Georgia, a lake in Massachusetts and a spring in Nevada. They are found across southern Florida. The only established, wild population is in Florida.
Site and Date of Introduction:
Outside of Florida: Tropical fish dealers in the US imported the walking catfish to be sold as pets. The walking catfish that were found in the US outside of Florida most likely came from aquarium releases (intentional or accidental).

Florida: In the early 1960's, the walking catfish was imported to Florida from Thailand for the aquarium trade. The first introductions apparently happened in the mid 60's when adult fish, imported to be brood stock, escaped from Penagra Aquarium in Broward County and/or from a truck transporting brood fish between Dade and Broward counties. In 1967, the state of Florida banned the importation and possession of walking catfish. However, this led to another release of the fish into the wild. Fish farmers in Tampa Bay who possessed the fish purposefully released them so that they would not be found in violation of the new law.

In 1968, this species was only found in three south Florida counties. However, by 1978, the walking catfish had spread to 20 counties in the southern half of the peninsula. The fish accomplished this migration by using the many hundreds of miles of interconnected canals across south Florida and by moving over land, typically during rainy nights. By the mid 1970's, the walking catfish was established in Everglades National Park and in Big Cypress National Preserve.

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