Their weight varies greatly - from small fish of around 1/2 lb to large specimens of around 20 lb. There are four strains of brown trout in Ireland: Dollaghan, Gillaroo, Sonaghen and Ferox. The Dollaghan is thought to have evolved from sea trout which were land locked many years ago.
The weight of these fish varies greatly - ranging from tiny ones weighing about 0.5 pounds to massive ones weighing around 9 kilograms. In the context of Ireland's brown trout, there are four distinct strains: Dollaghan, Gillaroo, Sonaghen, and Ferox. The origins of the Dollaghan strain are linked to sea trout that were once confined to land.