Eel-tailed catfish
Venomous freshwater catfish native to eastern Australia
The eel-tailed catfish is a venomous freshwater species native to the Murray-Darling river system in eastern Australia. It features a distinctive tapering tail and sharp spines, with populations declining significantly in southern regions due to habitat loss and introduced species.
- Venomous dorsal and pectoral spines cause painful wounds
- Builds stone nests up to one metre wide for spawning
- Populations in southern Murray-Darling are nearly extinct
- Grows up to 90 cm and weighs 6 kg
- Name tandan comes from an Aboriginal Australian language
What it is
This catfish has a solid, elongated body that tapers into a pointed, eel-like tail. Adults display colouration ranging from olive-green to brown or black on the back, with a white underside. They possess large heads, small eyes, and thick fleshy lips surrounding a downturned mouth. Four pairs of barbels help them locate food. A continuous fin margin runs along the posterior half of the body. The skin is tough and smooth. Sharp, serrated spines on the dorsal and pectoral fins are venomous and can inflict painful wounds.
Where it lives
Native to eastern Australia, this species inhabits the Murray-Darling river system. It prefers slow-moving streams, lakes, and ponds with fringing vegetation, often staying close to sand or gravel bottoms. It is more common in lakes than flowing water. While widespread historically, it is now absent from upland headwaters in the southern tributaries. Populations remain relatively secure in coastal catchments north of the Hunter River in New South Wales and in northern Murray-Darling reaches.
How it lives
Juveniles may form groups, but adults are usually solitary. Young fish feed on zooplankton and small insect larvae like chironomids. As they grow beyond 100 mm, they consume small fish. Adults eat shrimps, crayfish during warmer months, and midge larvae in winter. Their diet also includes mollusks and larvae from dragonflies, caddisflies, and mayflies. This species hosts intestinal parasites such as cestodes and nematodes. It swims near the bottom, using its barbels to detect prey in the sediment.
Breeding and life cycle
Spawning occurs in spring and midsummer when water temperatures reach 20–24 °C. One or two weeks before laying eggs, the fish construct large nests up to a metre wide using small stones and gravel. Eggs are deposited within these structures. One parent, or sometimes both, guards the nest until the eggs hatch. This nesting behaviour makes them vulnerable to siltation, which can smother the rocks required for reproduction.
Fish and people
Known locally as dewfish or jewfish, this catfish is a target for sport fishing and food. However, handlers must exercise caution due to venomous spines that cause severe pain. The name tandan derives from an Aboriginal Australian word recorded by Major Thomas Livingston Mitchell in 1832. While once a common food source, its declining numbers have reduced its availability in many parts of its former range.
Status and threats
Populations in the southern Murray-Darling Basin have declined severely since the 1980s, with many local groups now extinct. Threats include habitat degradation, barriers to movement, and competition from introduced carp and redfin perch. Siltation smothers spawning nests. The species is listed as Endangered in New South Wales, Threatened in Victoria, and Protected in South Australia. Northern populations appear more secure, particularly in upland reaches where water temperatures suit them.
Questions people ask about Eel-tailed catfish
Is the eel-tailed catfish dangerous to handle?
Yes, it has sharp serrated spines on its dorsal and pectoral fins. These spines are venomous and can cause very painful wounds if handled carelessly. Anglers should use proper tools when landing this fish.
Where does the eel-tailed catfish live?
It is native to eastern Australia, primarily in the Murray-Darling river system. It prefers slow-moving streams, lakes, and ponds with sand or gravel bottoms. It is rarely found in fast-flowing upland waters in the south.
What does the eel-tailed catfish eat?
Juveniles feed on zooplankton and insect larvae. Adults consume small fish, shrimps, crayfish, mollusks, and various aquatic insect larvae. Their diet shifts with seasons, including more midge larvae in winter.
Why are eel-tailed catfish populations declining?
Declines are caused by habitat degradation, dams blocking movement, and siltation covering spawning nests. Introduced species like carp and redfin perch compete for food and prey on young catfish.
Good reading and sources
- Eel-tailed catfish on WikipediaEncyclopedia
- More photos on Wikimedia CommonsPhotos
- Wikidata recordOpen data
The facts on this page come from the Wikipedia article "Eel-tailed catfish", 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.
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