Walking Catfish

About

Whether you may keep this fish depends entirely on where you live, and the answer changes at the border. In the United States it is federally prohibited: 50 CFR 16.13 lists, among injurious wildlife, 'Live fish or viable eggs of walking catfish, family Clariidae', so importing it or moving it between states is unlawful except under permit — and Florida banned importation and possession at state level back in the late 1960s, after brood stock escaped and the fish spread from three counties to twenty in a decade. USGS records it as established in Florida, present in the Everglades and Big Cypress since the mid-1970s, with failed introductions in California, Connecticut, Georgia, Massachusetts and Nevada. In the European Union the picture is the opposite: Regulation (EU) No 1143/2014's Union list of 114 invasive alien species contains no Clarias, and Lithuania's separate national list carries four fish — the round goby, the Amur sleeper, the monkey goby and the topmouth gudgeon — none of them a clariid. So in Lithuania this fish is lawful to buy and keep, and releasing it is not: the Ministry of the Environment states that the Law on Wildlife prohibits releasing or translocating alien-species animals into the wild. Underneath the law is a scaleless, air-breathing catfish that can leave the water. It seals its gills, stiffens them so they do not collapse, secretes mucus to stay damp and walks on its pectoral spines to the next pool; Wikipedia says it can survive eighteen hours out of water. Sizes are argued over — FishBase caps it at 47 cm total length, Wikipedia at almost 0.5 m, USGS at 61 cm in the native range, Seriously Fish at an uncorroborated 100 cm standard length while calling 45–60 cm 'a good size' in captivity. Most of the fish in the trade are albino or marbled aquarium strains; the wild form is plain brown with a white belly and is seen far less often.

Care

Hardy, undemanding and completely unsuited to a community tank. Seriously Fish asks for 210 x 120 x 90 cm — about 2,300 litres — for a fully grown adult, notes that floor space matters more than depth, and prescribes a soft substrate with driftwood, smooth rocks and lengths of pipe to hide in; plants are not essential and it will shove loose ones about, but nothing in the literature says it eats living plants. The lid is the whole game. This fish is an escape artist that is 'quite willing to leave the aquarium for a wander if the opportunity arises', so the cover must be heavy, tight and complete — and, because it is an air-breather that can literally drown if kept from the surface, a gap of humid air has to stay under it. Water chemistry barely matters: 20–26 °C, pH 5.5–8.0, hardness 2–25 °H, and it survives oxygen levels that would kill most tank fish. Company is the problem. It is highly predatory and will eat any fish it can fit in that wide mouth; tankmates must be large, robust and introduced bigger than the Clarias, because juveniles grow phenomenally fast. Starting with a group of young to obtain a pair is the standard route, but once a pair forms they turn territorial and everything else must come out — so buy as though you will end up with one fish, because you probably will. Feed adults every other day at most; this is a fish that does not know when to stop.

Diet

Greedy omnivore. Sinking pellets as a staple plus meaty frozen foods and a vegetable component; earthworm, prawn, mussel and white fish are readily taken. Adults do not need daily feeding, and overfeeding is the commonest mistake.

Telling males from females

What works for this species, most reliable first.

• Adult sizeA hint only · only across animals of the same age

  In many cichlids, catfish and loaches one sex simply grows larger — usually the male, though there are well-known reversals.

Also in these lists

Similar species

Same category and the closest water parameters — if this species isn't quite it, start here.

Sold in Lithuania

These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.

These links are unpaid: we get nothing for them and ask for nothing.

Frequently asked questions

What tank size does a Walking Catfish need?

A Walking Catfish needs an aquarium of at least 2300 litres (607.6 US gallons) with a footprint at least 210 cm (82.7 in) long — for this species, swimming length matters as much as raw volume.

What water parameters does a Walking Catfish need?

Walking Catfish does best at 18–28 °C (64.4–82.4 °F), pH 5.5–8 and a general hardness of 2–25 °dGH.

Is the Walking Catfish suitable for beginners?

Walking Catfish is a demanding species best attempted with some experience — it needs stable, closely watched conditions to thrive.

Sources

• FishBase — Clarias batrachus (Walking catfish)
• Seriously Fish — Clarias batrachus (Walking Catfish)
• USGS Nonindigenous Aquatic Species — Clarias batrachus (Walking Catfish)
• eCFR — 50 CFR 16.13, importation of live or dead fish, mollusks, and crustaceans (current text)
• Wikipedia — Walking catfish
• Wikipedia — List of invasive alien species of Union concern
• Kauno Tado Ivanausko zoologijos muziejus — Invazinės žuvų rūšys Lietuvoje
• LR aplinkos ministerija — Invazinių Lietuvoje rūšių sąrašas
• Lietuvos Respublikos aplinkos ministerija — Keičiasi laukinių gyvūnų, augalų ir grybų rūšių introdukcijos, reintrodukcijos ir perkėlimo reikalavimai