World-wide known by the commercial advantage of its ovocitos, call "caviar" as consumption product, is a species introduced accidentally in the river basin of the Silver from the liberation from a piscicultura located in the Negro river, tributary of the Uruguay river . It is evident that a great number of these units survived in free waters, since numerous captures have been registered, not only in the Uruguay river, but also in the River of the Silver and average and inferior Parana .

It is a fish on which the young in captivity practices, and is frequent to find it in aquariums, reason why a great dispersion has become, although in their waters of origin the populations are not abundant. He is original of the Nor This of Siberia, of low temperatures and possibly it finds some environmental resistance for his reproduction in our country. However, like with any new introduction, it is not known with certainty which will be its capacity of sobreexperience and dispersion.

It is easy superficially to recognize it by the presence of plates and the flanks of the body, with a head that extends in a length and pointed snout. The mouth is located in the base of the head and is protráctil. The superior lobe of the fin of great volume very is prolonged backwards. Anádromo is a migrador fish, of demersales habits and inhabits waters of little depth. It reaches about 30 kgs. of weight after many years. The males mature between the 9-15 years .