brown trout

Brown Trout

Scientific name: Salmo trutta (Linnaeus, 1758)
Forms / Sub-species: Sonaghen, Gillaroo, Ferox, Dollaghan,
Family: Salmonidae
Order: Salmoniformes
Class: Actinopterygii
Irish name: Breac Donn
Irish record angling fish(Lake): 11.85kg (1894, Lough Ennell);
Irish record angling fish (River): 9.072kg (1957, River Shannon)
Native species: Yes
Hybrids: Trout-Salmon; rare

Identifying features

Build varies according to food availability; coloration very variable. In acid waters, usually olive, bronze and gold, with numerous black and red spots; dark spots more or less round and often surrounded with a pale ring in limestone waters, often silvery, with x-shaped black spots and few or no red spots (except for adipose fin); numerous spots on gill-covers and cheeks, not regularly arranged; tail-fin usually not spotted, but spots may be present, especially on the upper lobe, in some large lake trout; size very variable, from 50g to over 9kg according to habitat and food supply4.

Environment and Habitat

Pelagic; migrate within freshwater only1; inhabit lakes and rivers; require at least moderately good water quality to thrive, especially cool temperatures and high dissolved oxygen levels; spawn in well-oxygenated gravel beds of streams where the female digs a redd2; juveniles usually remain in the river as long as there is good food availability; as they mature, older trout move to the larger deeper waters of the river main channel or associated lake 9;

European distribution

Europe and Asia: northwestern coast of Europe 71°N - 34°N, 25°W - 57°E; widespread throughout Irish rivers and lakes;

Economic value in Ireland

Valuable angling tourism species; farmed for angling and culinary purposes;

Red list status: Lower Risk

least concern

Irish legislation status

Brown trout fisheries are regulated by national or local legislation governing closed seasons, angling methods, size limits etc. e.g. Western Fisheries Region Conservation of Trout Bye-law No. 840, 2008

EU legislation status

Unprotected