DNA barcoding para discriminação de espécies congêneras de Cambeva (Teleostei)

Abstract

The Iguaçu River is a watercourse with several waterfalls and its geomorphology allowed a high endemism of the ichthyofauna. Its exuberant mouth, the Iguaçu Falls, make the basin known worldwide, with great appeal to tourism, being extremely important for the basic supply of water, production of electricity, fishing, agriculture, among others. Due to this great use of its resources, it also receives high loads of anthropogenic pollution, being ranked as the second most polluted river in Brazil. Among the endemic species of fish found in the Iguaçu River is the Cambeva mboycy, which is at risk of extinction (endangered category), with no studies about it. In this sense, the aim of the present work was to use the technique of DNA Barcoding to assess the genetic diversity and understand the phylogeographic patterns of fish species of the genus Cambeva and compare them with populations from two geographically separated locations in the Baixo Iguaçu region. The animals were obtained from tributaries located in the cities of Dois Vizinhos and Cascavel, in the southwest and west regions of the state of Paraná, respectively. 113 individuals were collected and DNA extraction from a fish muscle fragment was performed. After that, the individual DNA was amplified by PCR, using a fragment of the COI gene. Amplified DNA was sequenced and 45 samples were obtained. The sequences were edited and aligned manually with the BioEdit program, compared using the MEGA X program and the phylogenetic tree was built using the neighbor-joining algorithm. The barcoding DNA sequences, along with other information, will be made available in the world fish database; Fish Barcode of Life Initiative (FISH-BOL). It was noticed that the genetic variations observed in Cambeva species were associated with localities, making it possible to observe through the phylogenetic tree, instead of species, suggesting that the geomorphology of the Iguaçu River imposes a geographic barrier to gene exchange, contributing to the speciation process of the genus and increasing endemism.