Reproductive biology of Oligosarcus argenteus (Gunther, 1864) adult males and description of the gonadal maturation stages

Abstract

Oligosarcus argenteus belongs to the Acestrorhynchinae subfamily, being restricted to South America, and found in several Brazilian hydrographic basins, in lotic and lentic environments, where they are able to reproduce. With the purpose of studying the reproductive biology of the males from this species, many morphological parameters were analyzed during a 24 month period, as well as characterizing the different testicular maturation stages. A maturity scale, with three stages (I - Initial Maturing, II - Intermediate Maturing, III - Final Maturing) was proposed for the adult males of Oligosarcus argenteus. The reproductive period was established by the bimonthly frequency of spermatogenesis and by the gonadal maturation stages.