The Maroni is one of the most speciose basins of the Guianas and hosts a megadiverse freshwater fish community. Although taxonomic references based on morphological identification exist for both the Surinamese and Guianese parts of the basin, there are still taxonomic uncertainties concerning the status of several species. We used COI sequences of 1284 fish in conjunction with morphological and biogeographical evidence to assist with species delineation and discovery in order to validate and standardize the current taxonomy. This resulted in a final DNA barcode data set of 199 fish species (125 genera, 36 families and eight orders; 68.86% of strictly freshwater fishes from the basin), among which 25 are new putative candidate species flagged as requiring taxonomic update. DNA barcoding delineation through Barcode Index Numbers (BINs) revealed further cryptic diversity (230 BINs in total). To explore global genetic patterns across the basin, genetic divergence landscapes were computed for 128 species, showing a global trend of high genetic divergence between the Surinamese southwest (Tapanahony and Paloemeu), the Guianese southeast (Marouini, Litany, Tampok, etc.), and the river outlet in the north. This could be explained by lower levels of connectivity between these three main areas and/or the exchange of individuals between these areas and the neighbouring basins. A new method of ordination of genetic landscapes successfully assigned species into cluster groups based on their respective pattern of genetic divergence across the Maroni Basin: genetically homogeneous species were effectively discriminated from species showing high spatial genetic fragmentation and possible lower capacity for dispersal.

中文翻译：

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大型 DNA 条形码数据集的遗传景观聚类揭示了 Maroni 盆地淡水鱼类之间遗传差异的共享模式

Maroni 是圭亚那最特殊的盆地之一，拥有种类繁多的淡水鱼类群落。尽管该盆地的苏里南和圭亚那部分都存在基于形态学鉴定的分类学参考，但关于几个物种的状态仍然存在分类学上的不确定性。我们使用 1284 条鱼的 COI 序列结合形态学和生物地理证据来协助物种划分和发现，以验证和标准化当前的分类法。这产生了 199 种鱼类（125 属、36 科和 8 个目；占流域严格淡水鱼类的 68.86%）的最终 DNA 条形码数据集，其中 25 种是新的推定候选物种，被标记为需要分类更新。通过条形码索引号 (BIN) 进行的 DNA 条形码描绘揭示了进一步的神秘多样性（总共 230 个 BIN）。为了探索整个盆地的全球遗传模式，计算了 128 个物种的遗传差异景观，显示了苏里南西南部（Tapanahony 和 Paloemeu）、圭亚那东南部（Marouini、Litany、Tampok 等）、和北部的河流出口。这可以通过这三个主要区域之间较低水平的连通性和/或这些区域与邻近盆地之间的人员交流来解释。一种新的遗传景观排序方法根据物种在马罗尼盆地各自的遗传差异模式成功地将物种分配到集群组中：