@article{NagelKirschbaumEngelmannetal.2018,
  author    = {Nagel, Rebecca and Kirschbaum, Frank and Engelmann, Jacob and Hofmann, Volker and Pawelzik, Felix and Tiedemann, Ralph},
  title     = {Male-mediated species recognition among African weakly electric fishes},
  series = {Royal Society Open Science},
  volume    = {5},
  journal   = {Royal Society Open Science},
  number    = {2},
  publisher = {Royal Society},
  address   = {London},
  issn      = {2054-5703},
  doi       = {10.1098/rsos.170443},
  pages     = {8},
  year      = {2018},
  abstract  = {Effective communication among sympatric species is often instrumental for behavioural isolation, where the failure to successfully discriminate between potential mates could lead to less fit hybrid offspring. Discrimination between con- and heterospecifics tends to occur more often in the sex that invests more in offspring production, i.e. females, but males may also mediate reproductive isolation. In this study, we show that among two Campylomormyrus Africanweakly electric fish species, males preferentially associate with conspecific females during choice tests using live fish as stimuli, i.e. when all sensory modalities potentially used for communication were present. We then conducted playback experiments to determine whether the species-specific electric organ discharge (EOD) used for electrocommunication serves as the cue for this conspecific association preference. Interestingly, only C. compressirostris males associated significantly more with the conspecific EOD waveform when playback stimuli were provided, while no such association preference was observed in C. tamandua males. Given our results, the EOD appears to serve, in part, as a male-mediated pre-zygotic isolation mechanism among sympatric species. However, the failure of C. tamandua males to discriminate between con- and heterospecific playback discharges suggests that multiple modalities may be necessary for species recognition in some African weakly electric fish species.},
  language  = {en}
}
@article{NagelKirschbaumTiedemann2017,
  author    = {Nagel, Rebecca and Kirschbaum, Frank and Tiedemann, Ralph},
  title     = {Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes},
  series = {Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology},
  volume    = {203},
  journal   = {Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology},
  publisher = {Springer},
  address   = {New York},
  issn      = {0340-7594},
  doi       = {10.1007/s00359-017-1151-2},
  pages     = {183 -- 195},
  year      = {2017},
  abstract  = {In mormyrid weakly electric fish, the electric organ discharge (EOD) is used for species recognition, orientation and prey localization. Produced in the muscle-derived adult electric organ, the EOD exhibits a wide diversity across species in both waveform and duration. While certain defining EOD characteristics can be linked to anatomical features of the electric organ, many factors underlying EOD differentiation are yet unknown. Here, we report the differential expression of 13 Kv1 voltage-gated potassium channel genes, two inwardly rectifying potassium channel genes, two previously studied sodium channel genes and an ATPase pump in two sympatric species of the genus Campylomormyrus in both the adult electric organ and skeletal muscle. Campylomormyrus compressirostris displays a basal EOD, largely unchanged during development, while C. tshokwe has an elongated, putatively derived discharge. We report an upregulation in all Kv1 genes in the electric organ of Campylomormyrus tshokwe when compared to both skeletal muscle and C. compressirostris electric organ. This pattern of upregulation in a species with a derived EOD form suggests that voltage-gated potassium channels are potentially involved in the diversification of the EOD signal among mormyrid weakly electric fish.},
  language  = {en}
}