The objective of this work was to generate information about reproductive biology parameters of a curimbatá population for use in managing the species toward its conservation. Fish were monthly collected from February 2003 to September 2004 in two sites of the Mogi-Guaçu river. A total of 176 females and 140 males were captured. The parameters weight-length relationship, condition factor (K), gonad-somatic index (GSI), sex ratio and relative abundance were analyzed. Curimbatá adults from the Mogi-Guaçu river showed negative allometric growth. The highest values of condition factor (K) and GSI occurred during the reproductive period, when the sex ratio was 1:1. The period of curimbatá reproduction occurs between October and January, with peaks in November and December. Curimbatá males show anticipation of gonadal maturation in relation to females.
Condition factor; growth; gonad-somatic index; Prochilodus lineatus; sexual proportion
