Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva (PPG-GCBEv), Laboratório Temático de Biologia Molecular (LTBM), Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Brazil.
Coordenação de Ciências Biológicas, Universidade do Estado do Amazonas (UEA), Manaus, Brazil.
J Fish Biol. 2024 Jun;104(6):1924-1939. doi: 10.1111/jfb.15721. Epub 2024 Mar 29.
The fish fauna of the Tocantins River possesses many endemic species; however, it is little studied in molecular terms and is quite threatened by the construction of several hydroelectric dams. Therefore, the objective of this study was to identify the ichthyofauna of the Tocantins River using DNA barcoding. For this, collections were carried out in five points of this river, which resulted in the capture of 725 individuals from which partial sequences of the cytochrome oxidase subunit I (COI) gene were obtained for genetic analysis. A total of 443 haplotypes were recovered with the mean intraspecific K2P genetic distance of 1.82%. Altogether, 138 species were identified based on morphological criteria, which was a quantity that was much lower than that indicated by the four molecular methods (assemble species by automatic partitioning [ASAP], barcode index number [BIN], generalized mixed Yule coalescent (GMYC), and Bayesian Poisson tree processes [bPTP]) through which 152-157 molecular entities were identified. In all, 41 unique BINs were obtained based on the data generated in the BOLDSystems platform. According to the result indicated by ASAP (species delimitation approach considered the most appropriate in the present study), there was an increase of 17 molecular entities (12.32%), when compared to the number of species identified through their morphological criteria, as it can show cryptic diversity, candidates for new species, and misidentifications. There were 21 incongruities indicated between the different identification approaches for species. Therefore, it is suggested that these taxonomic problems be cautiously evaluated by experts to solve such taxonomic issues.
托坎廷斯河的鱼类区系拥有许多特有种；然而，在分子层面上的研究甚少，并且受到许多水力发电大坝建设的威胁。因此，本研究的目的是利用 DNA 条码对托坎廷斯河的鱼类区系进行鉴定。为此，在该河的五个点进行了采集，共捕获了 725 条个体，从中获得了部分细胞色素氧化酶亚基 I（COI）基因的序列，用于遗传分析。共获得 443 个单倍型，种内平均 K2P 遗传距离为 1.82%。总共根据形态学标准鉴定出 138 种，这一数量远低于通过四种分子方法（自动分区法 [ASAP]、条码索引数 [BIN]、广义混合 Yule 聚合法 [GMYC] 和贝叶斯泊松树过程 [bPTP]）鉴定出的 152-157 种分子实体。总共根据 BOLDSystems 平台生成的数据获得了 41 个独特的 BIN。根据 ASAP（本研究中考虑最适当的物种界定方法）的结果，与通过形态学标准鉴定的物种数量相比，增加了 17 个分子实体（12.32%），因为它可以显示隐生多样性、新种候选和误识别。不同物种鉴定方法之间存在 21 个不一致。因此，建议由专家谨慎评估这些分类问题，以解决此类分类问题。
