TY  - JOUR
A1  - Nagel, Rebecca
A1  - Kirschbaum, Frank
A1  - Engelmann, Jacob
A1  - Hofmann, Volker
A1  - Pawelzik, Felix
A1  - Tiedemann, Ralph
T1  - Male-mediated species recognition among African weakly electric fishes
JF  - Royal Society Open Science
N2  - 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.
KW  - Campylomormyrus
KW  - communication
KW  - electric fishes
KW  - pre-zygotic isolation
KW  - species recognition
Y1  - 2018
U6  - https://doi.org/10.1098/rsos.170443
SN  - 2054-5703
VL  - 5
IS  - 2
PB  - Royal Society
CY  - London
ER  - 
TY  - JOUR
A1  - Nagel, Rebecca
A1  - Kirschbaum, Frank
A1  - Tiedemann, Ralph
T1  - Electric organ discharge diversification in mormyrid weakly electric fish is associated with differential expression of voltage-gated ion channel genes
JF  - Journal of comparative physiology : A, Neuroethology, sensory, neural, and behavioral physiology
N2  - 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.
KW  - Weakly electric fish
KW  - Ion channels
KW  - Electric organ
KW  - Gene expression
KW  - Campylomormyrus
Y1  - 2017
U6  - https://doi.org/10.1007/s00359-017-1151-2
SN  - 0340-7594
SN  - 1432-1351
VL  - 203
SP  - 183
EP  - 195
PB  - Springer
CY  - New York
ER  -