The ‘Geophagus’ brasiliensis complex is one of the most abundant groups of cichlids from eastern coastal basins in South America. Traditionally, this fish group has been recognized as incertae sedis because of phylogenetic uncertainties and unclear taxonomy. In addition, the remarkable morphological, chromosomal, and DNA variation reported over recent years in several populations of these cichlids has increased the debate about their species richness and their distributional range. Here, we tested the presence of independent evolutionary lineages within the ‘G.’ brasiliensis complex, addressing their taxonomic status and evolutionary relationships, including a comparative analysis of genetic and morphological patterns, based on an extensive dataset, comprising 172 sampling sites along most of their known range using a mitochondrial marker, RADseq data and geometric morphometrics. The number of putative species in the present study varied from 9 to 11 depending on the molecular species delimitation methods used. Our results revealed at least two putative new taxa (‘Geophagus’ sp. Doce and ‘Geophagus’ sp. Upper Contas). Morphometric analyses, particularly those based on Canonical Variate Analysis (CVA), revealed significant morphological differentiation between species within the main clades. On the other hand, analyses of morphological phylogenetic signal and phylomorphospace provided no evidence of adaptive differentiation among these species. Thus, diversification in the ‘G.’ brasiliensis complex seems to have been influenced by hydrogeological events that promoted allopatry, such as the presence of paleodrainages and distributional reconfiguration through river captures. We propose major changes in the known distribution of some species within the complex and conservatively suggest the recognition of 10 species within the ‘Geophagus’ brasiliensis complex, with the potential for further dividing ‘G.’ rufomarginatus after additional taxonomic evaluation.

该“Geophagus”巴西复杂的是来自南美洲的东部沿海盆地鲷最丰富的群体之一。传统上，由于系统发育上的不确定性和分类标准不明确，该鱼群已被确认为不合格。此外，近年来，在这些丽鱼科鱼的几个种群中，形态，染色体和DNA发生了显着变化，这引发了人们对其物种丰富度和分布范围的争论。在这里，我们测试了“ G”内部是否存在独立的进化谱系。巴西利亚复杂，解决了它们的分类学地位和进化关系，包括基于广泛的数据集对遗传和形态学模式进行的比较分析，包括使用线粒体标记，RADseq数据和几何形态计量学的大部分已知范围的172个采样点。本研究中推定的物种数量从9到11不等，具体取决于所使用的分子物种定界方法。我们的研究结果揭示了至少两个推定的新分类单元（' Geophags'sp。Doce和' Geophagus'sp。上层Contas）。形态分析，特别是基于典型变异分析（CVA）的形态分析，揭示了主要进化枝之间物种之间的显着形态差异。另一方面，形态学系统发育信号和系统形态空间的分析没有提供这些物种之间的适应性分化的证据。因此，多元化的“ G. ”巴西复杂的似乎已经通过促进allopatry，如paleodrainages的存在和分布的重新配置，通过河流水文捕获事件的影响。我们建议对复杂物种中某些物种的已知分布进行重大更改，并保守地建议识别“巴西食豆”中的10种物种复杂，有可能进一步划分“ G”。rufomarginatus经过其他分类评估。