Diversidade genética de populações selvagens de Brycon melanopterus (Cope, 1871) da bacia Amazônica

Abstract

The composition of the Brazilian freshwater fauna is particularly very diverse and many of the fish species that are not found naturally outside of South America, especially when it comes to the Amazon. This diversity cover a large number of natural stocks and these have been suffering from the disorderly catch of fishery resources. The species Brycon melanopterus, known as jatuarana and matrinxã in Brazil and as Sabalo Negro in Colombia, is a species of Amazonian fish of great commercial importance, either by the appreciation of its meat by the consumer market or even as one of the species of aggressive behavior when captured by sport fisherman. This species occurs mainly in the central Amazon region where there is intense exploitation of natural stocks. This study aims to characterize genetically the wild populations of B. melanopterus in the Amazon basin. Sampling for this study were conducted in tributaries of the Amazon basin near the municipalities of Santarém and Óbidos located in Para State, Laranjal do Jari located in the state of Amapá, Manaus and Tefé located in the state of Amazonas and Leticia located in the Amazonas department in Colombia. The specimens were collected and stored to perform DNA extraction, amplification of the control region (D-Loop) of the mitochondrial genome (mtDNA) and subsequent sequencing. The populations studied were genetically structured, and the genetic diversity indexes were considered high when compared to other studies using the mtDNA D-loop region, in addition, they were found in natural populations of other species of Brycon genus. corroborates with the data obtained in this work. There was a population structure between Leticia and Laranjal do Jari, extreme capture locations, supported by FST results and haplotype tree. Therefore, the present work provided sufficient information to indicate that the genetic variability for this species is high when compared to other studies and a non homogeneous pattern of differentiation between the sampled sites. The study indicates indications that the management and conservation policies of B. melanopterus should consider the existence of at least two evolutionary units coexisting in the tributaries of the Amazon basin, offering perspectives for the use of different molecular markers that corroborate with the information obtained.