Abstract：
Ecological speciation within the mormyrid genus Campylomormyrus resulted in sympatric species exhibiting divergence in their feeding apparatus and electric organ discharge (EOD). This study documents the overall diet of the genus Campylomormyrus and examines the hypothesis that the Campylomormyrus radiation is caused by adaptation to different food sources. We performed diet assessment of five sympatric Campylomormyrus species (C. alces, C. compressirostris, C. curvirostris, C. tshokwe, C. numenius) and their sister taxon Gnathonemus petersii with markedly different snout morphologies and EODs using hybrid capture/HTS DNA metabarcoding of their stomach contents. Our approach allowed for high taxonomic resolution of prey items, including benthic invertebrates, allochthonous invertebrates and vegetation. Comparisons of the diet compositions using quantitative measures and diet overlap indices revealed that all species are able to exploit multiple food niches in their habitats, that is fauna at the bottom, the water surface and the water column. A major part of the diet is larvae of aquatic insects, such as dipterans, coleopterans and trichopterans, known to occur in holes and interstitial spaces of the substrate. The results indicate that different snout morphologies and the associated divergence in the EOD could translate into different prey spectra. This suggests that the diversification in EOD and/or morphology of the feeding apparatus could be under functional adaptation.
摘要：
金丝雀属的生态物种形成导致同胞物种在其摄食装置和电器官放电（EOD）方面表现出差异。这项研究记录了Campylomormyrus属的整体饮食，并研究了以下假设：Campylomormyrus辐射是由对不同食物来源的适应引起的。我们对五种同伴弯曲菌进行了饮食评估（C.alces,C.compressirostris，C.curvirostris,C.Tshokwe,C.numenius）和他们的姊妹分类单元Gnathonemuspetersii具有明显不同的鼻部形态和EOD，它们的胃内容物使用杂合捕获/HTSDNA代谢编码。我们的方法允许猎物的高分类分辨率，包括底栖无脊椎动物,异源无脊椎动物和植被。使用定量措施和饮食重叠指数对饮食组成进行比较后发现，所有物种都能够在其栖息地中利用多种食物位，那是底部的动物群，水面和水柱。饮食的主要部分是水生昆虫的幼虫，比如双翅目,鞘翅目和毛翅目,已知发生在衬底的孔和间隙空间中。结果表明，不同的鼻子形态和相关的EOD差异可以转化为不同的猎物光谱。这表明进料装置的EOD和/或形态的多样化可能处于功能适应下。
