Brown trout are a European species of salmonidfish that has been widely introduced into suitable environments globally.
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.
Brown trout are a freshwater species suited to clear, well oxygenated cold water between 4-19 degrees Celsius (slightly cooler than the optimum range forRainbow trout).
In other countries they will migrate between fresh and saltwater to breeding but this does not occur in Western Australia. Brown trout prefer river and stream habits with fast flowing water and stone or gravel bottoms, but also thrive in deep water impoundments.
Brown trout prefer water greater than 45cm deep and with extensive sections of water over 70cm. These depths and high-water flow are ideal and will generally facilitate a better food source and thus larger numbers of quality fish than those found in shallower streams.
Given good habitat and food, brown trout develop rapidly in the second and third years. Considered to be a 'residential' fish as it is very territorial and mature fish are likely to stay in a limited area for their lifetime.
Ideal trout streams should have spawning areas of gravel, with water depths 20-100 cm deep and fast flowing water. Extensive areas of coarse substrate (gravel and rubble) in adequate water depth and flow, will produce good quantities of macroinvertebrates (mudeyes, mayflies, stoneflies, snails and shrimp) to provide food. The optimum water temperature range for best metabolism and maximum growth is from 7-17°C. Juvenile trout avoid the higher water velocities, which often occur in the riffles, by sheltering within the coarse substrate.