Aquarist Atlas
Aquarist Atlas · the catfish of the world

Catfish

Catfish are one of the great success stories of fresh water — roughly one in twenty of all fish species, on every continent but Antarctica. This section covers the whole order, everything but the Corydoras and the plecos, which have atlases of their own: the African squeakers (Synodontis), the long-whiskered giants of the Amazon, the transparent glass catfish, the armoured talking cats, the wood-dwelling driftwood and banjo cats, the Asian bagrids and shark catfishes, the air-breathing walking and stinging cats, and the North American bullheads. They reward a keeper who reads the account first and punish one who doesn’t — many are sold tiny and grow to tankbusters, most are scaleless and med-sensitive, several carry venomous spines, and breeding is nothing like a tetra’s. Built to the same standard as the cichlid, cory and pleco pages — researched, cited, no Wikipedia, no invented facts.

© Adobe Stock

We cover the catfish (order Siluriformes) as a whole — every family the hobby meets — with two exceptions that already have their own sections: the plecos (Loricariidae) and the Corydoras-group cories. The non-cory armoured callichthyids (Hoplosternum, Megalechis, Dianema, Callichthys) do belong here. Following the Catalog of Fishes for valid names, we group the order by a friendly family-and-ecology axis rather than by clade, because the science is large and still moving. Four honest warnings run through every account. The size trap: many catfish are sold as charming juveniles and grow into pond- or public-aquarium fish that eat their tankmates — the adult size is stated plainly. Scaleless skin: most are naked or bony-plated, so they are sensitive to copper and full-dose medications. Spines: many lock their fin spines and several are genuinely venomous (the stinging catfish above all). And breeding is per-family — bubble-nesters, internal fertilisers, cuckoo parasites and farm-bred giants — never a default “egg-scatterer.” Read each account before you buy.

A boldly spotted Synodontis squeaker catfish hovering over dark sand
A squeaker (Synodontis) — Africa’s signature catfish. It locks and rasps its pectoral spines to “squeak”, several species swim and feed upside-down at the surface, and one, the cuckoo catfish S. multipunctatus, brood-parasitises mouthbrooding cichlids in Lake Tanganyika — its eggs are picked up and raised by the host. Hardy and long-lived, but match the species to the tank: they run from 6 cm to well over 30.
A dark, armoured catfish with a row of hooked bony scutes down its flank, over black sand
A thorny or talking catfish (family Doradidae) — armoured down each flank with a row of hooked bony scutes. It “talks” in audible clicks and locks rigid, barbed pectoral spines that tangle hopelessly in a net, so it is handled by hand, never netted. Peaceful toward anything too big to eat, it hoovers up small tankmates after dark.
A large, smooth-skinned grey catfish with a broad flat head and long barbels on the bottom
A giant sheatfish — the wels (Silurus) and its Old-World kin are among the largest freshwater fish on Earth, reaching well past two metres. It is the size trap in its most extreme form: a smooth, scaleless, temperate-water predator that swallows fish whole and belongs in a lake or public aquarium, never a living-room tank.
An elongate armoured catfish plated in two rows of bony scutes, among driftwood
An armoured callichthyid (Hoplosternum, Callichthys and kin) — the non-Corydoras cousins of the cories, plated in two rows of bony scutes. They gulp air at the surface and breed by building a floating bubble-nest that the male guards, which makes them one of the few genuinely home-breedable catfish in this section.
A young redtail catfish — dark back, white stripe and a bright orange-red tail — on sand
A redtail (Phractocephalus hemioliopterus) — the face of the size trap. Sold at a hand’s length, it reaches well over a metre and a huge weight, eats any fish it can engulf, and needs a home the size of a small pond. Many catfish are honest, rewarding aquarium fish; a few, like this one, simply are not — so every account states the adult size bluntly.

Photos © Adobe Stock

576 species in the atlas

Grouped by a friendly family-and-ecology axis — the squeakers, the long-whiskered cats, the glass & sheatfish cats, the thorny talking cats, the driftwood, banjo and bagrid cats, the air-breathing walking cats, the shark catfishes, the armoured callichthyids, the North American catfish and the order’s oddballs — rather than by the shifting family boundaries, though each account names its current family and authority. Siluriformes is one of the largest orders of fish; following the Catalog of Fishes and FishBase, the roster is vast and still being written up, and new accounts are added as they are researched.

Species

576 of 576 species

Squeakers & upside-down cats · 57

Family Mochokidae — the African squeakers (Synodontis) and their kin (Chiloglanis, Microsynodontis, Mochokus). They lock and rasp their pectoral spines to 'squeak', several swim and feed upside-down at the surface, and one, the cuckoo catfish Synodontis multipunctatus, brood-parasitises the mouthbrooding cichlids of Lake Tanganyika — its eggs are picked up and raised by the host. Mostly hardy, omnivorous and nocturnal; sizes run from 6 cm to well over 30 cm, so match the species to the tank.

Long-whiskered cats · 64

Pimelodidae plus the related Heptapteridae and Pseudopimelodidae — the long-whiskered catfish of the Neotropics. This group holds the classic SIZE TRAP: the pretty pictus (Pimelodus) stays modest, but the redtail (Phractocephalus, 1 m+) and the shovelnoses (Sorubim, Pseudoplatystoma, sailfin/tiger shovelnose) are sold as cute juveniles and grow into pond- or public-aquarium fish that eat any tankmate they can swallow. Scaleless and nocturnal; the smaller Rhamdia, Pimelodella and bumblebee Microglanis are the tank-suitable ones.

Glass & sheatfish cats · 53

Siluridae (the glass catfish Kryptopterus, Ompok, and the giant sheatfish Wallago and Silurus) plus the African Schilbeidae. The transparent glass catfish is a shoaling, skittish fish that must be kept in groups of six or more and refuses to thrive alone; the sheatfish and Wallago are the size trap of Asia (Wallago and the wels Silurus glanis exceed 1.5 m). Scaleless, nocturnal, largely piscivorous — the big ones are for ponds, not living-room tanks.

Thorny & talking cats · 53

Family Doradidae — the thorny or talking catfish (raphael Platydoras, Agamyxis, Megalodoras, Oxydoras). A row of bony, hooked scutes armours the flank, they 'talk' with audible clicks, and they lock rigid, barbed pectoral spines that tangle in a net — handle by hand, never net. Peaceful toward anything too big to eat but hoover up small tankmates at night. Some stay small; Megalodoras and Oxydoras become giants.

Driftwood cats · 54

Family Auchenipteridae — the driftwood catfish (Tatia, Centromochlus, Auchenipterus, Trachelyopterus). Nocturnal wood-dwellers with a remarkable trick: they use INTERNAL FERTILISATION — the male's anal fin is modified into an intromittent organ and the female stores sperm to spawn later, which is rare among catfish. Many are small, peaceful micro-predators that hide by day and hunt the water column after dark.

Banjo cats · 43

Family Aspredinidae — the banjo catfish (Bunocephalus and kin), named for the flat, broad head and thin tail that make the fish look like the instrument. Cryptic, slow, harmless bottom-sitters that bury in sand and mimic a dead leaf; some brackish species carry their eggs on the belly. Peaceful and easily bullied or outcompeted at feeding time — a specialist's oddball, not a community centrepiece.

Bagrid cats · 53

Family Bagridae — the Asian bagrid catfish (Mystus, Hemibagrus, Bagrichthys, Sperata, Bagrus in Africa). Another size trap: the small Mystus are fine community fish, but Hemibagrus wyckioides and Sperata reach a metre and are predators. Scaleless, nocturnal, with sharp locking pectoral spines that deliver a painful jab. Match the species to the tank and expect any fish small enough to fit the mouth to vanish.

Airbreathing & walking cats · 44

Clariidae (the walking catfish Clarias, Heterobranchus) and Heteropneustidae (the stinging catfish Heteropneustes). They breathe air with an accessory organ, survive foul water, and Clarias can wriggle overland — which has made it a notorious invasive. Heteropneustes is genuinely VENOMOUS: its pectoral sting causes intense pain, so it is handled with great care. Large, greedy, aggressive and long-lived; most outgrow a community tank.

Shark catfishes · 31

Pangasiidae — the freshwater shark catfish of South and Southeast Asia, including the iridescent 'shark' (Pangasianodon hypophthalmus) and the critically endangered Mekong giant catfish. The iridescent shark is the definitive size trap: sold at 8 cm, it grows past a metre, panics and injures itself in tanks, and belongs only in a pond or public aquarium. Most are farm- or hormone-bred rather than home-bred; state the adult size bluntly. (The marine sea catfishes, family Ariidae, are excluded — this atlas covers freshwater and brackish fish only.)

Armored callichthyids · 19

Subfamily Callichthyinae — the non-Corydoras armored catfish (Hoplosternum, Megalechis, Dianema, Callichthys, Lepthoplosternum). Two rows of bony plates armour the body, they gulp air at the surface, and they breed by building a FLOATING BUBBLE-NEST that the male guards — one of the few genuinely home-breedable catfish here. Peaceful, hardy, mid-sized. (Their small cousins the Corydoras have their own section.)

North American catfish · 43

Family Ictaluridae — the bullheads, the channel and blue catfish, the flathead, and the tiny madtoms (Noturus). The bullheads and channel cats are cold-hardy pond fish that grow large and are illegal to release in many places; the madtoms are small, secretive stream fish, several with a mild venom gland at the pectoral spine. Nocturnal, scaleless, omnivorous — a temperate group, not tropical.

Other & oddball cats · 62

The rest of the order's aquarium oddities: the electric catfish (Malapteruridae, Malapterurus — a real electric discharge), the frogmouth catfish (Chacidae, Chaca — a leaf-mimic ambush predator), the Asian hillstream Sisoridae (Glyptothorax) and Akysidae, the African loach catfishes (Amphiliidae), the whale catfishes (Cetopsidae), and the notorious candiru (Trichomycteridae) — kept and covered for honesty and curiosity, not as easy community fish.

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