Desenvolvimento ovocitário e gonadal do parachromis managuensis(Günther, 1867)(osteichthyes, cichlidae) em um lago da região neo tropical

Abstract

Parachromis managuensis(Günther, 1867) is a species of Cichlid that was introduced in Brazil whose studies on its reproductive biology are still scarce. The objective of this study was to describe the oocyte and gonadal development of Parachromis managuensis(PISCES, CICHLIDAE) in a lake in the semi-arid region of Pernambuco. The collections were carried out monthly among the Pajeú river basin, located in the Pernambuco sertão. A total of 85 females of P. managuensis were collected, with total weight (PT) varying from 0.28 g to 161.00 g and total length (CT) ranging from 14 to 162 mm. Based on the histological analysis, germ cells (181 ± 31 μm), pre-vitellogenic oocytes (248 ± 68 μm), vitellogenic oocytes (477 ± 103 μm), mature oocytes (417 ± 116 μm) and oocytes atresia (513 ± 57 μm). The stages of gonadal development were classified into: maturation (initial and final), mature and spawned. From the histological observations, it is evident that the species presents a very early maturation and a split spawning, with the presence of up to four oocyte lots that increase synchronously in diameter until the spawning phase. The biotic and abiotic factors favor its development, growth and reproduction, and aggressive behavior as a predator of native species and early maturation suggest the reasons for its great evolutionary success in the semiarid region of Pernambuco. The results of the present study provide important information that can be used to control their populations.