Populational analysis of "curimbatá" Prohilodus lineatus, from Mogi Guaçu River ( Characiformes, Prochilodontidae)

Abstract

This study aims to verify at the popuIationaI condition of "curimbatá", Prochilodus lineatus VaIenciennes, 1836, from Mogi Guaçu River (São Paulo), through the analysis of the popuIationaI bioIogy parameters. The reproduction occurs from November to December. Ring formation in scaIes is annual and takes place during the reproductive period. UntiI seven and six rings in femaIe and maIe, respectively, were found. Rapid growth in length occurs during the first year of life, before the first sexual maturation size. However, the opposite occurs for the growth in weight. The estimated ÆŸ value suggests isometric growth type. The estimated size of first sexual maturation was 241.8 mm and 248.2 mm, for males and females respectively. The estimates of the length and age of first sexual maturation suggest that this species presents populational self-adjustment. This feature, when associated with the physical and chemical conditions of the river, is favoring the preservation and the maintenance of this species in the ecosystem.