Trout cod
An endangered Australian freshwater predator native to the Murray-Darling basin.
The trout cod is a large predatory fish found in the south-eastern rivers of Australia. Once widespread, it is now critically rare due to habitat loss and competition from introduced species. Genetic studies confirmed its status as a distinct species in the early 1970s.
- Distinct from Murray cod with a pointed head and overhanging jaw.
- Endangered due to introduced trout and redfin perch.
- Spawns at cooler temperatures using rocky substrates.
- Single wild population remains in the Murray River.
- Hybridizes with Murray cod, hindering conservation.
What it is
This fish belongs to the genus Maccullochella and the family Percichthyidae. It resembles the Murray cod but has distinct features including a pointed head with an overhanging upper jaw and slightly larger eyes. The body is cream to light grey on the belly, with bluish-grey backs covered in irregular black speckles. Fins are rounded with white edges, and pelvic fins feature trailing white filaments. Adults reach at least 80 cm and 16 kg.
Where it lives
Historically widespread in the south-east corner of the Murray-Darling river system. It primarily inhabited larger upland rivers and creeks, often co-existing with Macquarie perch and blackfish. A single wild population remains in the Murray River where upland habitats transition to lowlands. Lowland populations have largely disappeared due to regulation and degradation.
How it lives
Trout cod are carnivores feeding on fish, crustaceans, insects, and small vertebrates. Larvae eat zooplankton. They prefer cooler, faster currents and stay close to cover like snags or rocks. Radio tracking shows small home ranges, though they migrate upstream to spawn before returning to their original locations.
Breeding and life cycle
Sexual maturity occurs at 3 to 5 years, smaller than Murray cod. Spawning happens earlier and at lower temperatures, around 15 degrees Celsius, using rocks as a substrate. Wild spawning has never been observed. Artificial breeding uses hormone injections. They hybridize with Murray cod, complicating recovery efforts.
Fish and people
Recognized by fishermen and scientists since the 19th century. Commercial and recreational fishing occurred historically. The species is now totally protected. Hatchery stockings have created small breeding populations in the Murrumbidgee River, though long-term sustainability is unclear. Many stocking attempts failed due to inappropriate habitat selection.
Status and threats
Listed as Endangered by the IUCN and under various Australian acts. Decline caused by overfishing, habitat degradation, de-snagging, and invasive species. Introduced redfin perch cause heavy predation in lowlands. In uplands, introduced rainbow and brown trout dominate, outcompeting and preying on trout cod larvae. No upland rivers are reserved as trout-free zones for native species.
Questions people ask about Trout cod
What is the scientific name of the trout cod?
The scientific name is Maccullochella macquariensis. It belongs to the family Percichthyidae and is closely related to the Murray cod.
Why is it called bluenose?
In Victoria during the 19th and early 20th centuries, commercial and recreational fishermen commonly referred to this species as bluenose cod or simply bluenose.
How does it differ from the Murray cod?
It has a pointed head with an overhanging upper jaw, larger eyes, and lacks the speckling on the head seen in Murray cod. It also matures at a smaller size.
Where can trout cod be found today?
Only one wild, naturally occurring population remains in the Murray River. This area represents a transition zone between upland and lowland river habitats.
What threatens the trout cod?
Threats include overfishing, habitat degradation, and introduced species. Redfin perch prey on them in lowlands, while introduced trout dominate and compete in upland rivers.
Good reading and sources
The facts on this page come from the Wikipedia article "Trout cod", 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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