Composição em tamanho dos peixes (Actinopterygii, Teleostei) de ribeirões da bacia do rio Tibagi, Paraná, Brasil

The standard length of 7610 specimens of 43 species from eight streams of rio Tibagi basin was obtained in order to analyze the means of fish sizes. The higher mean size was observed in Gymnotus carapo Linnaeus, 1758 (165,5 mm) and the smaller, in Phalloceros caudimaculatus (Hensel, 1868) (16,25 mm). Some fish like Acestrorhynchus lacustris (Reinhardt, 1874), Leporinus obtusidens (Valenciennes, 1836), Gymnotus carapo Linneus, 1758 and Synbranchus marmoratus Bloch, 1795 can reach big or medium size when adults but were collected only young, evidencing they use some streams in beginning of life....