Estratégias reprodutivas das assembléias de peixes de reservatórios do Estado do Paraná e bacias limítrofes

Abstract

Reproductive strategies of fish assemblage were evaluated in order to determine which is best in relation to colonization of reservoirs. Samples were taken during the year 2001 in 31 reservoirs distributed in the Paraná State and limitrophe rivers (Paranapanema, Tibagi, Piquiri and Iguaçu, all affluents of the Paraná; and the East basin with rivers that empties directly into the Atlantic Ocean), using gill and seining nets. A total of 149 species were caught. Among them, 89.3% are sedentaries or perform short migration (Group I) to spawn in the impounded area or adjacent tributaries. The other 10.7% are long distance migratory species (Group II). For species of the Group I, 54.4% do not develop parental care whereas 29,5% present some type of parental care, the other 5.4% present internal fecundation. In all reservoirs, species of the Group I that do not develop parental care were more abundant considering number of individuals. Most advantageous features for these species are the high relative fecundity, spawn in several batches, long spawning period, small eggs and rapid maturation. Median or large sized species (belonging to Group I or II) and those that develop parental care were important regarding to biomass.