T he walking catfish Clarias batrachus is a species of freshwater fish native to Southeast Asia. In Florida, they grow to about 20 inches long and 2. Most walking catfish in the wild are a uniform shade of gray-brown with white spots or flecks on their sides, though albinos are sometimes encountered.
These fish like to move from one body of water to another in search of food or a better living space, and they do this by wiggling across land.
They use their pectoral fins to stay upright and wriggle in a snake-like movement to flop across land, usually during wet weather. On the internet, there are anecdotal stories of walking catfish owners who have lost the fish because they literally walk away. Today, the US government requires a federal permit to own one of these fish but there are still pet stores advertising them for sale.
Reason s Why it has Become Established: Walking catfish are hardy fish which can thrive where many other fish struggle to survive. In addition to lakes and rivers, they can be found in brackish waters or warm, stagnant, often hypoxic waters such as muddy ponds, canals, ditches, swamps and flooded prairies. They can remain dormant through periods of drought and go several months without eating.
When they do eat, they consume a wide variety of prey. In addition, walking catfish have high fecundity and the males guard the eggs and free-swimming young, giving them a better chance of survival than the native, non-protected young of other species. Ecological Role: Walking catfish are voracious, opportunistic feeders who are mainly active at night. They consume a wide variety of prey including eggs and larvae of other fishes, small fishes, a number of invertebrates including crustaceans and insects and sometimes plant materials.
In densely populated drying pools, these fish become even more indiscriminate and quickly consume most other species present. Walking catfish of all ages and size fall victim to a wide variety of predators including other fish, reptiles, birds and mammals. They are also killed by cars when migrating en masse across streets from one body of water to another.
Benefit s : The walking catfish can survive extended periods out of water. In its native areas, this makes it an attractive food fish which easily can be sold and traded live. The species is fished by subsistence fisherman as well as managed at commercial farming operations.
Threat s : Walking catfish have been know to invade aquaculture farms and eat large amounts of fish stock. Fish farmers in Florida have had to put up fences or build levees to keep them out. An additional threat to catfish fisheries, specifically, is the fact that wild walking catfish carry the disease enteric septicemia ESC caused by the bacterium Edwadsiella ictaluri.
Wild walking catfish could infect farmed catfish with the disease. In Florida, the total impact on native species is unknown. We do know, though, that walking catfish are extremely pervasive across southern Florida and many scientist consider the introduction of the walking catfish into the area as one of the most harmful introduction in North America.
Walking catfish are especially devastating in small wetland pools during the dry season where they can quickly become the dominant species. The species that appear to be most affected are native centarchids and catfishes.
The walking catfish is a tropical fish and, if introduced into other warm areas of the US, the spread of the fish could mirror what happened in Florida. Southern Texas and Hawaii are examples of two US areas that could be vulnerable. Control Level Diagnosis: I rank this threat as medium priority.
Report Issues Report fish kills, wildlife emergencies, sightings, etc. Go Outdoors Florida! Walking Catfish. Appearance Elongated, gray, and scaleless catfish-type body with a large mouth, sharp pectoral spines, and four pairs of barbels; light to dark gray in color, but albinos occur; noted for ability to breath air and make short overland movements by pulling themselves along with their pectoral fins much like an infantry-man scooting under barbed wire; early accounts that this fish would eliminate native fishes were erroneous, and it has not had major detrimental effects; species occasionally abundant and still considered undesirable.
Range: Most commonly encountered in Everglades and associated canals, but also occurs throughout central and south Florida; first reported in in Broward County and later in Hillsborough County, now these two populations have joined; abundance has decreased since Habitat Prefers shallow and highly vegetated water bodies; sometimes abundant in small deeper ponds without normal complement of native fishes.
Behavior Spawning Habitats: Little known, but reports from India indicate spawn early in rainy season when build nests in submerged vegetation; adhesive eggs laid on vegetation, and guarded by male.
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