Reproductive biology of Hemiancistrus sp. ( Osteichthyes, Loricariidae ) from Sinos River, RS

Abstract

In this paper it was studied some aspects of reproduction for Hemiancistrus sp. (Loricariidae) from Sinos River (29°46'41"S; 50°26'46''W). The macroscopic morphological changes in the gonads of 381 specimens of Hemiancistrus sp. were classified in five maturation stages: young (A), maturation (B), mature (C), spent (D) and resting (E). The frequency of adults of both sex and the seasonally variation of the average Gonadosomatic Index (IGS) values showed that L₅₀ for Hemiancistrus sp. is 134 mm and L₁₀₀ is 190 mm. The relative frequency of maturity stages showed the spawning occurs from spring to summer. This species has total spawning. The sexual proportion was not significantly different.