Eel-Tailed Catfish in the Murray-Darling Basin

Scientific name

Tandanus tandanus

Status in NSW

Endangered population. How to ID an Eel Tailed Catfish (Photo: B. Vercoe)


  1. Long, continuous fin comprising of the second dorsal, anal and caudal fins which are joined to form an eel-like tail.
  2. Rear portion of the body is compressed.
  3. Colour ranges from grey to brown, usually mottled with dark brown/black blotchings and a whitish underbelly. Larger fish have less mottling and can be more green in colour fading to white below. Skin is smooth with no scales.
  4. Small eyes.
  5. Down turned mouth surrounded by barbels.


Can grow up to 900mm and 7kg, however fish over 2kg are exceptional.


Eel Tailed Catfish are naturally distributed throughout the Murray-Darling Basin and in the Eastern drainages NSW north of Newcastle. Eel Tailed Catfish numbers in the Murray-Darling Basin have declined due to a range of impacts including invasive species, habitat degradation, cold water pollution and fishing pressures and are now virtually absent from the Murray, Murrumbidgee and Lachlan catchments.


The Eel tailed catfish is a non-migratory, benthic (bottom dwelling) species. It is relatively sedentary and adults typically only move within a 5 km range. They are generally more active at night compared with during the day.

They can be found in a diverse range of freshwater environments including rivers, creeks, lakes, billabongs and lagoons. They prefer clear, sluggish or still waters, but can also be found in flowing streams with turbid waters. Substrates range from mud to gravel and rock.

Eel Tailed Catfish (Photo: B. Vercoe)

Why is the Murray-Darling Basin population of Eel-Tailed Catfish threatened?

  • Loss of suitable habitat (lakes, billabongs, lagoons) through river regulation.
  • Competitive and predatory interactions with introduced species such as Common Carp (Cyprinus carpio) and Redfin Perch (Perca fluviatilis).
  • Loss of habitat and spawning sites through siltation.
  • Reduced success of spawning and recruitment due to alterations to flow patterns and flooding regimes.
  • Reduced habitat and loss of temperature spawning cues due to cold-water discharge from the base of large dams and high-level weirs.
  • Run-off of chemical pollution into waterways, including agricultural pesticides.
  • Historical commercial and recreational overfishing.
Eel Tailed Catfish

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