Catfish

Catfish (order Siluriformes) are diverse ray-finned fishes named for their barbels, lacking scales and ranging from tiny parasitic species to very large commercial species.

catfishesNematognathi

Last Updated Mar 9, 2026 · 4 sources

Species Guide

What to know about catfish

A clean field guide focused on habitat, identification, behavior, and conservation context without burying the useful parts.

Catfish (order Siluriformes, also called Nematognathi) are a diverse group of ray-finned fish. They are named for their prominent barbels, which resemble a cat's whiskers, though not all species have prominent barbels. All siluriformes lack scales and instead have either smooth skin or armour-plated bodies. The order is defined by features of the skull and swimbladder. Catfish vary greatly in size and behavior: some are among the largest freshwater fish (for example the Mekong giant catfish, the wels catfish, and the piraíba), while others are detritivorous or scavenging bottom feeders, and a few are tiny ectoparasitic species such as the candiru. Many larger species are farmed or fished for food (for example Pangasius and Clarias), and many smaller species (for example members of Corydoras) are kept in aquaria. In parts of the Southern United States, regional slang names for catfish include "mud cat", "polliwogs", or "chuckleheads", with different meanings in different places.

Catfish exhibit a wide range of behaviors and movement patterns: some species are large-bodied and range widely, many are bottom-dwelling detritivores or scavengers, and some tiny species are ectoparasitic.

Diet varies by species: many are detritivorous or scavenging bottom feeders, while some species are parasitic; others (including large species) are not described here as exclusively one feeding type.

The strongest linked planning options currently surface around destinations such as Akumal, Playa del Carmen, Tulum and countries such as Republic of Serbia, Slovakia, Belarus for divers building trips around catfish.

Identification

How to identify catfish

The visual markers divers can use underwater, plus the species most likely to cause confusion.

Key identification markers

Barbels (whisker-like structures)

Many species have prominent barbels resembling a cat's whiskers, though not all catfish have prominent barbels.

Lack of scales

All siluriformes lack scales and instead have either smooth skin or armour-plated bodies.

Skeletal and swimbladder features

The order is defined by distinctive features of the skull and swimbladder.

Range and Movement

How catfish move through the world

The broad range, seasonal movement, or migratory behavior that shapes where divers encounter this species.

Catfish exhibit a wide range of behaviors and movement patterns: some species are large-bodied and range widely, many are bottom-dwelling detritivores or scavengers, and some tiny species are ectoparasitic.

Diet

What catfish tend to eat

Useful feeding context that often explains habitat, movement, and encounter style.

Diet varies by species: many are detritivorous or scavenging bottom feeders, while some species are parasitic; others (including large species) are not described here as exclusively one feeding type.

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Responsible Encounters

How to dive with catfish

Conservation-minded guidance for divers who want the encounter without adding pressure.

Give catfish space, avoid blocking the animal's path, and follow local site and operator rules for wildlife interactions with freshwater fishes.

Field Notes

Interesting things worth knowing

Useful species context that makes the encounter more meaningful once you are underwater.

Field notes

Extremes in size

Catfish include some of the largest freshwater species (Mekong giant catfish, wels catfish, piraíba) and some of the smallest, including parasitic candiru.

Human uses

Many larger species are farmed or fished for food, and many smaller species are popular in aquaria.

Regional slang

In the Southern United States, regional slang names like 'mud cat', 'polliwogs', or 'chuckleheads' are used for catfish with varying meanings.

Top Destinations

Top destinations to see catfish

Destinations surfaced from the linked dive spots associated with this species.

Top Countries

Top countries for catfish

The strongest country-level starting points currently linked to this species.

Top Dive Spots

Top dive spots for catfish

Directly linked dive spots where this species already shows up in the planning data.

Barbora dive spot

Barbora

Barbora is a calm freshwater lake dive with training objects.

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Betonjerka dive spot

Betonjerka

Bela Crkva training lake with variable visibility.

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Carrière de Barges dive spot

Carrière de Barges

Club-managed quarry with deep walls, relics, and good infrastructure.

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Carrière de La Gombe dive spot

Carrière de La Gombe

Deep freshwater quarry with caves, aircraft, and organized club access.

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Cascades dive spot

Cascades

Shallow freshwater canal dive near the anchor park.

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Cenote Tajma  Ha dive spot

Cenote Tajma Ha

Advanced halocline cenote circuit with light shafts and cavern rooms.

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FAQ

Frequently asked questions

Clear planning and conservation answers written for search visibility and AI retrieval.

Research Sources

Catfish information sources

Primary and credible references behind the field-guide and conservation claims on this page.

Sources 4Last Updated
Catfish · Encyclopedia · Wikipedia

Supporting wildlife source.

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