Ripsaw catfish: Large thorny catfish native to South American rivers.

The ripsaw catfish is a large species of thorny catfish found in major South American river basins. It grows up to one metre long and uses bony scutes for defence. The fish migrates annually to spawn and supports local fisheries and the aquarium trade.

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Largest member of the Doradidae family
Migrates up to 400 km to spawn
Produces sound by rubbing spines against bone
Females lay up to 250,000 eggs
Defensive thorns can injure handlers

What it is

This large catfish belongs to the family Doradidae and is known for its defensive armour. It possesses bony plates called scutes along its sides, each bearing sharp thorn-like projections. These structures protect it from predators but can injure humans who handle the fish. The body is dark on top and lighter underneath, with a narrow shape near the chest fins. Its mouth faces downward, suited for feeding on the riverbed. Unlike some relatives, its eyes sit on the side and rear of the head rather than on top.

Where it lives

The species inhabits the Amazon, Essequibo, and São Francisco river systems across seven South American nations. It prefers muddy streams and lakes where water temperatures stay between 24 and 30 degrees Celsius. During wet seasons, it moves into flooded basins and large freshwater lakes. As waters recede, it returns to main river channels. Some individuals have been recorded in the Andes at elevations near 900 metres. This wide distribution relies on the extensive network of rivers and seasonal floodplains.

How it lives

These fish often form schools and spend much of the day hidden under cover. They are rarely seen in open water and may remain concealed even in darkness when kept in captivity. Older specimens tend to move more freely regardless of light conditions. They feed by sifting through sand, using taste receptors in their mouths to find food. Their diet includes detritus, insect larvae, and small crustaceans. The fish can produce sounds by rubbing spines against bone structures, a behaviour known as stridulation, likely used for communication or warning.

Breeding and life cycle

Reproduction involves an annual migration called the piracema, which lasts about four months. As the dry season begins in June, the fish swim upstream for distances up to 400 kilometres. Spawning occurs during the rainy season when high water levels offer protection for adults and young. Females release up to 250,000 eggs, though few survive to adulthood. Sexual maturity is reached at a length of roughly 54 centimetres. This long migration helps disperse the population and reduces vulnerability to local environmental changes.

A drawing made by EveryFish from what this page says. It is a diagram, not a picture of the real fish.

Fish and people

Local communities catch this catfish for food, noting its flesh resembles salmon in appearance. It also appears in the global aquarium trade, often sold as a juvenile under names like black talking catfish. Buyers frequently underestimate its final size, as it requires very large tanks to thrive. While generally peaceful, it may consume smaller tankmates. The species has not been bred successfully in captivity. It gained media attention through appearances in wildlife television programmes. Handlers must be careful due to its sharp lateral thorns.

Status and threats

The International Union for Conservation of Nature lists the species as Least Concern. However, it faces threats from human development in the Amazon basin. Hydroelectric dams pose a significant risk by blocking migratory routes essential for spawning. Because the fish takes several years to reach sexual maturity, its ability to recover from population declines is limited. Pollution and habitat alteration further pressure freshwater ecosystems. Parasite infections are common, with studies showing high prevalence of various worm and protozoan species in wild populations.

Questions people ask about Ripsaw catfish

How big does the ripsaw catfish grow?

It is the largest species in its family, reaching lengths of up to 100 centimetres and weights of 13 kilograms. Due to this substantial size, it requires very large enclosures when kept in aquaria.

Why is it called a talking catfish?

The fish produces audible sounds through stridulation. It rubs ridges on its pectoral spines against the cleithrum bone in its shoulder girdle. These noises may serve to warn predators or communicate with other fish.

Is the ripsaw catfish dangerous to keep?

It is generally peaceful but has sharp thorn-like projections on its bony scutes. These defensive structures can injure handlers during capture or maintenance. It may also eat very small tankmates in an aquarium setting.

What does the ripsaw catfish eat?

It is an omnivore that feeds mainly on bottom sediments. Using taste receptors in its mouth, it sifts through sand to find detritus, insect larvae, and crustaceans. In captivity, it accepts prepared foods readily.

Good reading and sources

Where this page comes from

The facts on this page come from the Wikipedia article "Oxydoras niger", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). EveryFish rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.

It may contain mistakes, and figures change over time. Nothing here is investment or buying advice. If something is wrong, tell us. Last refreshed 2026-11-15.

Ripsaw catfish