Weightlenght relationship and condition factor of Rhamdia hilarii Valenciennes, 1840 ( Osteichthyes, Siluriformes, Pimelodidae )

Abstract

The weight-length relationship of a sample of 1490 individuals of Rhamdia hilarii can be described by the following equations:

Males W_t = 0.0043 x L_t ^3.2055

Females W_t = 0.0037 x L_t ^3.2538

No significant difference between the sexes was indicated by "t" tests being the relation to be expressed by the equation:

W_t.= 0.0039 x L_t ^3.2321. The condition factor (K e K₁ ) was determined in relation to the months of the year and total length of individuals, considering females and males separately. The greater values were observed during the pre-spawning season. The decrease of K values coincides with the reproduction process.