FaunaHub

Catfish

FishFreshwaterBottom-dweller

A channel catfish (Ictalurus punctatus) with long barbels near the mouth.

Channel catfish (Ictalurus punctatus).

Image: Engbretson, Eric (USFWS), Public domain, via Wikimedia Commons (USFWS).

Overview

Catfish make up the order Siluriformes, a very large and diverse group of mostly freshwater fish named for the whisker-like barbels around the mouth. There are thousands of species worldwide, ranging from tiny aquarium corydoras to giant river catfish. This page is a group-level overview; the channel catfish (Ictalurus punctatus) is used as a familiar reference. Most catfish lack scales and many are bottom-oriented.

Habitat & Range

Catfish occupy an enormous range of mostly freshwater habitats — rivers, lakes, streams, and ponds — on every continent except Antarctica, with a few species living in brackish or marine waters. Many are bottom-dwellers adapted to slow or still water, and some tolerate low-oxygen conditions. Habitat and range vary greatly by species, so no single description fits all catfish.

Diet

Most catfish are omnivores or scavengers, using their barbels and keen senses of taste and smell to find food along the bottom, including invertebrates, plant matter, detritus, and other fish. Some are specialised predators. Diet varies widely by species; this page describes general feeding ecology rather than aquarium feeding amounts.

Behavior

Many catfish are most active at night or in low light, relying on their barbels and senses rather than vision in murky water. Behaviour ranges widely: some are solitary, some shoal, and some show parental care of eggs and young. Certain catfish have spines or, in a few species, mild venom used in defence, so wild and aquarium catfish should be handled with care. Behaviour depends strongly on the species.

Human Interaction & Conservation

Catfish are important to people as food fish in fisheries and aquaculture, as angling targets, and — for smaller species like corydoras — as popular aquarium fish. Released or introduced catfish can become invasive in some regions. Because the group is so large, conservation status varies enormously by species and should be checked against current sources rather than assumed. Aquarium catfish are pets, not wildlife to be released.

Appearance & Recognition

The defining feature of catfish is the set of barbels — fleshy, whisker-like sensory organs around the mouth that give the group its name. Most catfish have smooth, scaleless skin or bony plates rather than typical scales, and many have a sturdy spine at the front of the dorsal and pectoral fins. Body shape ranges from the small, armoured corydoras to long, powerful river giants.

Similar Animals

Catfish are ray-finned fish like the other fish covered on FaunaHub, but their barbels and (usually) scaleless skin set them apart. Small aquarium catfish such as corydoras are often kept with community fish like tetras and guppies, while large wild catfish share rivers with carp and other big freshwater fish.

Freshwater aquarium basics →Aquarium care hub →

More photos of the catfish

Two channel catfish resting on a gravel bottom.

Channel catfish showing the barbels that give catfish their name.

Image: U.S. Fish and Wildlife Service Southeast Region, Public domain, via Wikimedia Commons (USFWS).

Frequently Asked Questions — Catfish

Why do catfish have whiskers?
The "whiskers" are barbels — sensory organs rich in taste and smell receptors that help catfish find food in murky water or at night, often along the bottom. They are the feature that gives catfish their name.
Are aquarium catfish and giant river catfish the same?
They belong to the same broad group (order Siluriformes) but are very different. Aquarium species such as corydoras stay small, while some wild river catfish grow very large. This is why the page is a group-level overview rather than a single-species account.
Can catfish sting?
Many catfish have stiff spines on the dorsal and pectoral fins, and some species have mildly venomous spines used in defence. For this reason, wild and aquarium catfish should be handled carefully and with appropriate guidance.

Sources and further reading

Authoritative wildlife references used for general educational context. Conservation status should always be verified against current IUCN Red List data. External links open in a new tab.