Catfish Species: Types, ID Marks and Biggest Records

About 3,093 living species in about 36 families, all in the order Siluriformes, which makes catfish the second or third most diverse order of vertebrates (Wikipedia, 2007 count). They live in fresh or coastal water on every continent except Antarctica, with the most species in tropical South America, Asia and Africa. What they share:

• Barbels in pairs, up to four pairs
• No scales: either bare skin or armour plates, as in the plecos
• Fin spines, often venomous: as many as half of all catfish may be venomous (Wikipedia)
• Taste all over: many larger catfish have chemoreceptors across the whole body, so they taste whatever they touch

So 'what species of fish are catfish' has a wide answer: from the tiny cory in a home aquarium to 290 kg river giants.

In the US, anglers usually mean the 'big three' plus the bullheads. Field & Stream groups them this way:

• Channel catfish: silver to grey, young fish with black spots, deeply forked tail; usually under 10 lb, record 58 lb (1964)
• Blue catfish: grey, forked tail, no black spots and a straight-edged anal fin; 100 lb fish are fairly common, record 143 lb from John Kerr Reservoir on the Virginia and North Carolina border (2011)
• Flathead catfish: yellowish-brown and mottled, flat head, rounded tail, lower jaw jutting out; typically 4 to 40 lb
• Brown bullhead: drab brown with darker mottling on the rear half; 8 to 12 inches
• Black bullhead: dark brown to black with a yellow to creamy belly and fully dark whiskers; 8 to 13 inches
• Yellow bullhead: yellow to olive-yellow with a rounded tail; usually under 10 inches

The quick split: forked tail means channel or blue; rounded or square tail means flathead or a bullhead. We have full ID pages for the channel catfish, blue catfish, flathead catfish, brown bullhead and yellow bullhead.

The giants from the sources on this page, heaviest first:

• Mekong giant catfish (Thailand, Laos, Vietnam): a 293 kg (646 lb) fish in 2005 (Wikipedia); Field & Stream says up to 400 lb and over 9 ft, and a species of concern from overfishing
• Piraiba (Amazon): rod-and-reel record 295 lb (2007), and known to grow over 450 lb (Field & Stream)
• Wels catfish (Europe and western Asia): can exceed 2.5 m (Wikipedia); 200 to 300 lb fish are common according to Field & Stream
• Blue catfish (US): record 143 lb, 2011 (Field & Stream)
• Redtail catfish (Amazon): black and white with a bright red tail; trophies over 60 inches and 100 lb (Field & Stream)
• Channel catfish (US): record 58 lb, 1964 (Field & Stream)

At the other end, some catfish mature at only 1 cm (Wikipedia).

Catfish is a major food fish. Channel catfish support a US aquaculture industry worth about $450 million a year (Wikipedia). The FDA's advice about eating fish puts both catfish and tilapia in its lowest-mercury 'Best Choices' group, with 2 to 3 servings a week of 4 ounces suggested for pregnant and breastfeeding people. On mercury the two are equal; the sources here do not rank one as healthier overall.

For wild fish, Field & Stream says channel catfish eat best at 1 to 4 lb, that many rate flatheads the best of the big three, and that large blues can taste muddy. It also warns that big, old catfish can build up mercury and other contaminants, so check your state's consumption advisory for the water you fish. Imported Pangasius (basa, swai) is a different family and cannot be sold as catfish in the US.

A few things set them apart from other fish (Wikipedia unless noted):

• They taste with their skin, which lets them feed in muddy water and at night
• Many are venomous: fin spines on up to half of all species can deliver venom; Field & Stream notes a black bullhead's pectoral spines can cause a burning sensation lasting up to a week
• Some breathe air, and several families can survive in low-oxygen water
• Huge size range: from 1 cm to nearly 300 kg

Handle any catfish from behind the pectoral spines, and see a doctor if a spine wound swells, turns red or the pain is severe.

Field & Stream lists the main methods used for catfish in the US: trotlines, jug fishing, drifting, jigging and noodling (catching catfish by hand). Rules on trotlines, jugs and hand fishing differ by state, so check your state's fishing regulations first.

Any fish with barbels gets called a catfish. Common mix-ups:

• Common carp: has barbels at the corners of the mouth but is covered in large scales, which no catfish has; see our common carp page
• Sturgeon: barbels in front of the mouth, but rows of bony plates along the body; see our white sturgeon page
• Pangasius (basa, swai): a true catfish, but only the family Ictaluridae may be marketed as catfish in the US, under a 2003 law, so it is sold as basa or swai (Wikipedia)

The scale check is the fastest: scales mean it is not a catfish.

Almost all of them. Most catfish families live only in fresh water; the exceptions are the families Ariidae (ariid sea catfishes) and Plotosidae, plus a few species in Aspredinidae and Bagridae that are found in salt water (Wikipedia). Even the sea catfishes are mixed: Wikipedia says the roughly 143 ariid species live mainly in the sea but include many freshwater and brackish ones.

Freshwater catfish you are most likely to meet:

• Wild in North America: channel, blue and flathead catfish and the bullheads, covered in the sections above
• In aquariums: Corydoras, bristlenose and other plecos, otocinclus, Synodontis, pictus and upside-down catfish
• Giants: the Mekong giant catfish, the piraiba and the redtail catfish of South America

If you caught a catfish in the sea along the US Atlantic or Gulf coast, it is most likely a hardhead catfish (Ariopsis felis), common from Massachusetts to Mexico and often called a bait stealer, or the less common gafftopsail catfish (Bagre marinus), which anglers rate more highly as a game and food fish (Wikipedia).

Many are, but size decides which. Aquarium catfish fall into three groups:

• Small and easy: Corydoras such as the panda and pygmy cory, otocinclus and bristlenose plecos. See our corydoras page and armored catfish page.
• Medium: Synodontis, pictus and upside-down catfish. LiveAquaria describes its larger catfish as peaceful additions to a large community tank that need both meaty and plant-based food.
• Tank-busters: the redtail catfish reaches about 1.8 m and 80 kg, eats anything that fits in its mouth, and Wikipedia says it needs at least 10,000 litres (2,600 US gallons) when fully grown. Juveniles are often sold without a warning about adult size, and owners who cannot keep them have released them into non-native waters (Wikipedia).

Two handling cautions apply to all of them. As many as half of all catfish species may be venomous through their fin spines (Wikipedia), so move them with a net or container rather than bare hands. And never release an aquarium catfish: Wikipedia names Pterygoplichthys plecos released by fishkeepers, and walking catfish in Florida, among invasive catfish.

Prices checked on 25 September 2026: AquaticArts listed albino bristlenose plecos from $9.99, panda corys from $19.99, pygmy corys from $16.99 and an L236 cracked zebra pleco at $74.99; LiveAquaria listed porthole catfish at $11.99, redtail catfish at $59.99 and Synodontis angelicus at $124.99.