Animal Species:Brown Trout, Salmo trutta Linnaeus, 1758

The Brown Trout is an introduced species that occurs in cool streams, lakes and reservoirs of south-eastern Australia and south-western Western Australia.  It is a popular angling fish.

Brown Trout in Thredbo River

Brown Trout in Thredbo River
Photographer: Sascha Schulz © Sascha Schulz

Standard Common Name

Brown Trout

Alternative Name/s

Sea Trout


The Brown Trout is a stout bodied fish with a large mouth, a single soft rayed dorsal fin and a dorsal adipose fin. Its colouration is variable with age and habitat. It is usually silvery or olive with dark spots on the sides of the body. The spots are often surrounded by a lighter halo - those on the lower sides may be pale or reddish-orange.

Juvenile Brown Trout are easily confused with juvenile Rainbow Trout, Oncorhynchus mykiss. Tarmo Raadik of the Arthur Rylah Institute for Environmental Research stated that "One thing which stands out with Brown and Rainbow trout is that the adipose fin of Rainbow Trout is usually a little transparent but also has a black edge around it, plus it is SOMETIMES spotted, that of Brown Trout in contrast is not transparent, never has any spots, but more significantly has a red to orange dorso-posterior edge."

Size range

It grows to 1.4 m in length (20 kg) although in Australia it only reaches 90 cm (14 kg).


The Brown Trout is native to coastal North Atlantic from Scandinavia to North Africa and east to the Caspian Sea. It was introduced to Australia from Europe in the 1860s.

In Australia it occurs from north-eastern New South Wales south to Tasmania and west to South Australia. It also occurs in south-western Western Australia. 

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information.  Source: Atlas of Living Australia.

Salmo trutta

Distribution by collection data

Ozcam map of Brown Trout specimens in the Australian Museums.

What does this mean?


It inhabits cool streams, lakes and reservoirs.

Feeding and Diet

This species eats small fishes, insects, molluscs and crustaceans. It is a predator of small native species such as galaxids.

Economic/social impacts

It is a popular angling species,



What does this mean?


  1. Allen, G.R. 1989. Freshwater Fishes of Australia. T.F.H. Publications. Pp. 240.
  2. Allen, G.R., Midgley, S.H. & M. Allen. 2002. Field Guide to the Freshwater Fishes of Australia. Western Australian Museum. Pp. 394.
  3. Davies, P.E. & R.M. McDowall. in McDowall, R.M. 1996. Freshwater Fishes of South-Eastern Australia. Reed Books. Pp. 247.
  4. Merrick, J.R. & G.E. Schmida. 1984. Australian Freshwater Fishes. Biology and Management. John R. Merrick. Pp. 409.


Mark McGrouther , Senior Fellow
Last Updated:

Tags fishes, ichthyology, Brown Trout, Salmo trutta, introduced species, popular angling fish, cool streams, lakes, reservoirs, stout body, large mouth, silvery, olive, dots/spots, > 1m, coastal waters,