01976nas a2200169   4500008004100000022001400041245012300055210006900178260001600247520138800263100001601651700001901667700002101686700002201707700002101729856005601750       2020                        eng d  a0269-765300aMorphological differentiation in African weakly electric fish (genus Campylomormyrus) relates to substrate preferences0 aMorphological differentiation in African weakly electric fish ge  cApr-04-20213 a<p>Under an ecological speciation scenario, the radiation of African weakly electric fish (genus Campylomormyrus) is caused by an adaptation to different food sources, associated with diversification of the electric organ discharge (EOD). This study experimentally investigates a phenotype&ndash;environment correlation to further support this scenario. Our behavioural experiments showed that three sympatric Campylomormyrus species with significantly divergent snout morphology differentially react to variation in substrate structure. While the short snout species (C. tamandua) exhibits preference to sandy substrate, the long snout species (C. rhynchophorus) significantly prefers a stone substrate for feeding. A third species with intermediate snout size (C. compressirostris) does not exhibit any substrate preference. This preference is matched with the observation that long-snouted specimens probe deeper into the stone substrate, presumably enabling them to reach prey more distant to the substrate surface. These findings suggest that the diverse feeding apparatus in the genus Campylomormyrus may have evolved in adaptation to specific microhabitats, i.e., substrate structures where these fish forage. Whether the parallel divergence in EOD is functionally related to this adaptation or solely serves as a prezygotic isolation mechanism remains to be elucidated.</p>
1 aAmen, Rahma1 aNagel, Rebecca1 aHedt, Maximilian1 aKirschbaum, Frank1 aTiedemann, Ralph  uhttp://link.springer.com/10.1007/s10682-020-10043-3