Brown Trout

Scientific name: Salmo trutta (Linnaeus, 1758)
Irish name: Breac Donn
Forms/Sub-species: Ferox, Sonaghan, Gillaroo, Croneen, Dollaghan
Hybrids: Trout-salmon hybrids sometimes occur but are rare
Native species: Yes
Irish record angling fish (Lake): 11.85kg (1894, Lough Ennell)
Irish record angling fish (River): 9.072kg (1957, River Shannon)

Description & Distribution

Description & Distribution

The brown trout is very variable in appearance, depending on its habitat and food. Brown trout usually have a pale belly with greenish grey/olive brown/golden flanks and a darker back with a reddish-brown/orange adipose fin. Brown trout are pigmented with spots, mostly blackish but sometimes with reddish spots.

Moreover, brown trout have the ability to make their body colour lighter or darker to match their surrounding habitat, thereby camouflaging themselves. In general, brown trout from acidic, less productive waters tend to be smaller and darker in colour, whereas trout from limestone, more productive waters tend to be larger and lighter in colour.

Brown trout are native to the river basins of Europe and North Africa draining into the Black Sea, Mediterranean Sea, Northeast Atlantic, North Sea, Baltic Sea, and White Sea. As a favourite angling species, brown trout have been widely introduced to other temperate parts of the world.

Brown trout are the most widespread fish in Ireland and are found in practically every river, stream and lake in the country.