The Zambezi grunter, Parauchenoglanis ngamensis, is currently distributed across four (sub)basins in southern and south-central Africa, namely the Okavango, upper Zambezi, Kwanza, and Kasai. The present study used a combination of molecular (barcoding), colour pattern, and other morphological data to explore the possible existence of hidden species diversity within this species. Based on the available samples, analyses of molecular data uncovered seven well-supported (.96–1.00 Bayesian posterior probabilities) candidate species, with 1.6%−8.5% genetic divergence between them. These, in addition to two more candidate species without genetic data, exhibited a combination of consistent colour pattern and other morphological differences that supported their distinction. The present study redescribes P. ngamensis, which is confined to the Okavango and upper Zambezi (sub)basins, and describes eight new species: two from the Kwanza Basin and six from the Kasai sub-basin. The fact that some of the species occur allopatrically, whereas others are sympatric and even syntopic indicates the complex palaeogeographical history of these basins. In addition, the high species diversity discovered in the Kasai sub-basin seems to be related to its highly peculiar hydrography. Accurate delimitation of species boundaries and mapping of their distribution is crucial for conservation assessments and guiding their protection.

中文翻译：

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九合一：来自非洲南部和中南部的广泛分布的赞比西咕噜鱼 Parauchenoglanis ngamensis（Siluriformes：Auchenoglanididae）中隐藏物种多样性的综合分类学证据


赞比西咕噜鱼 （Parauchenoglanis ngamensis） 目前分布在非洲南部和中南部的四个（子）流域，即奥卡万戈河、赞比西河上游、宽扎河和开赛河。本研究结合使用了分子（条形码）、颜色模式和其他形态学数据，以探索该物种中可能存在隐藏的物种多样性。根据可用样本，分子数据分析发现了 7 个得到充分支持 （.96-1.00 Bayesian posterior pro概率） 的候选物种，它们之间存在 1.6%-8.5% 的遗传差异。除了另外两个没有遗传数据的候选物种外，这些物种还表现出一致的颜色模式和其他形态差异的组合，支持它们的区分。本研究重新描述了仅限于奥卡万戈和赞比西河上游（子）流域的 P. ngamensis，并描述了八个新物种：两个来自宽扎盆地，六个来自开赛子流域。一些物种异位出现，而另一些物种是同源甚至同位的，这一事实表明这些盆地复杂的古地理历史。此外，在开赛子流域发现的高物种多样性似乎与其高度奇特的水文有关。准确划定物种边界并绘制其分布图对于保护评估和指导其保护至关重要。