Gonadal Development of the Piau Leporinus copelandii (Characiformes, Anostomidae) in a Tropical River in South-eastern Brazil

Histological analysis of the gonadal development of Leporinus copelandii Steindachner, 1875, a rheophilic Characiformes species in the Paraiba do Sul River, South-eastern Brazil, was described. We expect that this species adapt gonadal development to succeed in this river basin that has its longitudinal profile blocked by several impoundments. Fishes were examined by routine macroscopic and histological techniques. Stages of oocyte and spermatocyte development were described, and gonadal maturation was proposed. Mean oocyte diameter obtained from histological observations increased from the pre-spawning (4.2-175.5m) to spawning (148.5-262.0m) phases, followed by a sharp decrease in the post-spawning (27.0-56.7m) phase. Based on occurrence of different oocytes phases and oocyte size distribution, this species has group-synchronic development of oocytes. Further studies are necessary to clarify the spawning grounds for L.copelandii in the Paraiba do Sul River basin, especially considering that several impoundments obliterate the natural river course and this could limit spawning grounds.