Although it is native exclusive right of Europe and of the west of Asia , widely it has been distributed anywhere in the world.
It has taken great importance lately, due to the resistance that presents to the denominated disease whirling disease, that has devastated ample sectors of rivers of the United States , very famous by its quality of fishing of rainbow and cuthroat.
In Argentine waters it has prospered and it develops statures very superior to its places of origin very well. When it has the opportunity to lower to the sea, in waters with temperatures that are to him favorable, it acquires great dimensions and it has turned to the river Grande de Tierra of the Fire the fishing boat better described as the world.
It is characterized by its golden coloration; its back is generally brown, the silver-plated flanks and the yellowish belly. It has orange dots in flanks and dark very well-known spots with I pull ahead slightly clearer in the flanks, until good below the lateral line, the back and the opérculos. The fatty fin presents an orange coloration generally. The fin of great volume can have spots but - in general they are encasas and they are located in the superior lobe.
It has varied forms: the fario trout or of river, is of so large minor, its coloration is gilded with orange dots and is more sedentary than the one of lake. The migratory lacustrine form more is silverplated. The marine form reaches a development average greater than the locked up forms.
There is one more a silver-plated form in the lakes, that can be still confused easily with the locked up salmon and with the silver-plated trout rainbow. Difference of first by its greater head in relation to the body; to have pedúnculo of great volume more thickness and the fin of great volume of straight edges, and to have dark spots with clear edges in almost all the body, mainly the back, the opérculos and the fins. The brown ones which they have possibility of migrating to the sea, in the province of Santa Cruz and Land of the Fire, when they return to the rivers show a similar silver-plated coloration the one of the salmon. The brown trouts are very voracious and of a noticeable regime piscívoro, but in its diet they are gotten up, in addition to the fish, crabs, insects and lobsters of river.
Of the naturalized trouts, they are longevas more. They have been exemplary of 10 to 15 years of age and still more. The statures surpass the 100 centimeters and the 10 kilograms of weight. The record of capture by sport fishing was registered in the lake Nahuel Huapi in 1952: a trout of 16.300 kilograms . It is possible to be observed embalsamada in the seat of the Association of Hunting and Fishing of San Carlos de Bariloche. It requires of a close rank of temperatures but that the rainbow and has established healthy populations in the artificial dams of the Limay river.