Brown trout are very attractive fish.  They are similar to the salmon.  They have dark backs with pale sides, and have reddish spots with pale edges. Their bellies are a creamy white. Juvenile and immature trout have bluish-grey spots, and mature males have a strongly curved lower jaw.

Brown trout are found throughout the British Isles, where they inhabit well-oxygenated streams and rivers.  They feed on invertebrates, insect larvae, aerial insects, and molluscs, as well as the occasional fish and frog. They breed between January and March. The maximum-recorded life span of a brown trout is 5 years.

Brown trout are very popular with anglers, and are an economically important species.  Numbers of trout are maintained in many areas by artificial introductions.

More information and images of brown trout are available on the Arkive website.
http://www.arkive.org/species/ARK/fish/Salmo_trutta_fario/