02463nas a2200157 4500008004100000022002500041245016500066210006900231260001600300520186800316100001602184700002202200700002202222700002102244856004002265 2023 eng d a0962-1083, 1365-294X00aDiet in phenotypically divergent sympatric species of African weakly electric fish (genus: Campylomormyrus)—A hybrid capture/HTS metabarcoding approach0 aDiet in phenotypically divergent sympatric species of African we cDec-21-20233 a

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.

1 aAmen, Rahma1 aHavenstein, Katja1 aKirschbaum, Frank1 aTiedemann, Ralph uhttp://dx.doi.org/10.1111/mec.17248