Curve of growth and first sexual maturation of mandi Pimeludos maculatus Lac. 1803 (Pisces, Siluroidei)

The purpose of this paper is to establish a correlation between the next parameters, age and length, in order to attain the growth curve and to determine the length and age at the first sexual maturation of "mandi", Pimelodus maculatus. The age was determined by the translucents rings present in the lapilli otoliths and it was observed that its formation is annual. By fitting mean total lengths of age-groups defined by otolith analyses with the von Bertalanffy equation, it was found: L sub( proportional to ) = 56,5 cm; k = 0,1938 to females L sub( proportional to ) = 45,4 cm; k = 0,2104 to males The first sexual maturation is attained at 18 and 19 cm in males and females, respectively, at the age of 1,5 and 2 years.