02333nab a2200325 a 4500 AR-ReUNN 20260702003059.0 260630s2007 ag |||||||||||||||||spa spa eng Bonetto, Argentino a. 77121 Canón Verón, Marta B. 76054 Roldán, Dante o. 147459 Nuevos aportes al conocimiento de las migraciones de peces en el Río Paraná / Argentino A. Bonetto, Marta Canón Verón, Dante Roldán 2007 12 páginas Disponible en estante de INICNE New contributions to the knowledge of fish migrations in the Paraná River Studies on fish migration in the Paraná River were performed during the period 1975-1981, mainly in the join of Paraná and Paraguay Rivers, as well as the High Paraná, based on capturing, tagging and relasing of fishes. Lea`s hydrostatic tag was used to mark fish, obtained by netting to avoid capture injuries. Results are as follows: -Registered migratory tendencies of Characoids fish confirm as a general rule, previous statements on the literature about the Paraná and tributaries. -Data obtained on other Characoids and Siluroids, permit to clarify unknown aspects of their behaviour. -Obtained data are partially contradicting with Godoy`s statements on fish migration in the Upper Paraná, but agree with other authors` results on the Middle and Lower reach. So, two main kinds of migratory behaviour are shown: one related to breeding in which fish are recorded to move long distances, is the "active migrants" ecotype. The other referred to species intermixed with the above mentioned, in which fish do not require a great displacement for that purpose, is of the "passive migrants" ecotype. It seems to be a high proportion of passive migrants among fish populations in the river reaches studied, particularly in the Middle Paraná River Migración 6725 Peces de Agua Dulce 6471 Cria 116255 Argentina 4258 Freshwater Fish 117439 Inland Waters 117440 Migrations 146988 Breeding 147041 Ecosur 0325-108X v. 8 n. 16 (1981) 234603 ART (INICN)39229 234803 234803 234803 AR-ReUNN spa AR-ReUNN aacr2