Rainbow trout
Oncorhynchus mykiss
The rainbow trout usually reaches a size of 25 to 30 cm, but in the largest and most productive rivers it may exceed 60 cm in length. It has black dots on the back, on the head and caudal and dorsal fins. The body is silver, a little greenish, and is traversed by a bright pink band.
Is native from North America. It has been introduced to much of the world and is one of the most farmed fish on fish farms. In Catalonia you can find some populations that breed freely in the Llobregat basin, Francolí, Ter and Segre.
It lives in mountain rivers of cold and oxygenated waters. Reproduction is later than that of the brown trout, and takes place between February and April. The diet is based on all kinds of invertebrates, and larger individuals are fish predators.
It can have negative impacts on brown trout and other native fish.
Distribution
Brook trout
Salvelinus fontinalis
It is a medium-sized fish, that in Catalonia does not usually reach the 40 cm. He has a big mouth, with well-developed teeth. The scales are very small and barely visible. The body is greenish, with small clear spots and marbled spots on the back. During the breeding season, the ventral area turns red.
It is a species native to North America. It is introduced in some lakes in the Pyrenees of Lleida and Andorra.
Brook trout requires cold, well oxygenated waters from high mountain rivers and lakes. It breeds in autumn. The brook trout diet consists of invertebrates, amphibian larvae and small fish.
It competes with the brown trout in the places where they coexist. It also negatively impacts amphibian and invertebrate populations in high mountain lakes.
Distribution
Alpine char
Salvelinus umbla
Alpine char is a fish that can reach large sizes, but the populations living in Catalonia in general do not exceed 30 cm in length. The body is quite elongated, and is covered with very small scales. The coloration is gray-bluish, with small light-colored dots.
It lives in some lakes in the Alps, and has been introduced to many Pyrenean lakes on the French side. In Catalonia it is only found in some lakes in the Aran Valley.
The typical habitat is high mountain lakes with very cold waters. It feeds on invertebrates and small fish.
Distribution
