The Murray cod: Murray River legend

The Murray cod (Maccullochella peelii) is one of Australia’s most notable freshwater fish and is native to the Murray–Darling Basin. It is the country’s largest freshwater species, capable of growing over 1.8 metres long and weighing more than 100 kilograms. The size of a large human! 

Beyond its size, it holds deep cultural importance, with First Nations stories revealing a giant Murray cod whose movements created the Murray River itself.

Once abundant across inland waterways, Murray cod populations have declined due to habitat loss, altered river flows and barriers such as weirs. They are now a threatened species, and restoring the complex river habitats they depend on is important for their survival.

Michelle Slater, OzFish Project Manager for Northern Victoria said, “The Murray cod isn’t just a fish, it is part of the identity of the Murray River and the communities along it. For First Nations people, it holds deep cultural and spiritual meaning, and for locals today it’s a symbol of the river’s health and heritage”

Life beneath the surface

Murray cod spend most of their lives in deep river holes or slow-moving stretches of water, where they rely on instream cover such as fallen timber, rocks and undercut banks. These structures provide protection, resting spots and ambush points for feeding. Juveniles favour rocky or woody areas, while older fish often claim large logs or hollows as permanent homes.

Cod are long-lived, with some individuals reaching 50 years of age. They are highly territorial and their need for secure shelter doesn’t just help them survive day to day, it is vital for reproduction.

Breeding and shelter needs

Murray cod typically reach maturity at around five years of age and begin spawning in spring when water temperatures exceed 15°C. Females lay adhesive eggs on hard surfaces such as logs, clay banks or rocks. The male then guards the nest for up to two weeks, fanning the eggs and protecting them from predators until they hatch.

For this process to succeed, cod need stable hard surfaces and secure hollows. Without suitable shelter, their eggs can be washed away or eaten. Decades of snag removal and river modification have drastically reduced the availability of these nesting sites, leaving cod with fewer safe places to breed.

Enter the Grand Fish Hotels

To help reverse this decline, Murray River Trials and OzFish have launched the Grand Fish Hotels for Murray Cod fundraiser. These enormous, purpose-built habitat structures are designed to replicate the natural features that cod need to thrive.

Each grand fish hotel is constructed from river red gum, concrete and stainless steel. Approximately 2.6 metres wide and 1.8 metres high, each hotel weighs over a tonne and is built to last for around 100 years.

Inside, concrete pipes provide safe cavities where female cod can lay their eggs, while the overall structure offers protection for both adults and juveniles. Once installed, the grand fish hotels instantly create complex, durable shelter within degraded waterways — bringing back the kind of habitat that once defined healthy rivers.

“These grand fish hotels are like underwater houses for Murray cod, giving them safe places to shelter, breed and raise the next generation, “ said Ms Slater.

How you can help

With your support, our target is to raise funds to construct and deploy grand fish hotels in the Murray–Darling basin. Every dollar raised goes towards the cost of materials to build these structures and then to install them in the Murray River near Renmark, South Australia.

All donations over $2 are tax-deductible.

Click here to make a donation.