Electric pulse characteristics can enable species recognition in African weakly electric fish species

Abstract

Communication is key to a wide variety of animal behaviours and multiple modalities are often involved in this exchange of information from sender to receiver. The communication of African weakly electric fish, however, is thought to be predominantly unimodal and is mediated by their electric sense, in which species-specific electric organ discharges (EODs) are generated in a context-dependent and thus variable sequence of pulse intervals (SPI). While the primary function of the electric sense is considered to be electrolocation, both of its components likely carry information regarding identity of the sender. However, a clear understanding of their contribution to species recognition is incomplete. We therefore analysed these two electrocommunication components (EOD waveform and SPI statistics) in two sympatric mormyrid Campylomormyrus species. In a set of five playback conditions, we further investigated which components may drive interspecific recognition and discrimination. While we found that both electrocommunication components are species-specific, the cues necessary for species recognition differ between the two species studied. While the EOD waveform and SPI were both necessary and sufficient for species recognition in C. compressirostris males, C. tamandua males apparently utilize other, non-electric modalities. Mapped onto a recent phylogeny, our results suggest that discrimination by electric cues alone may be an apomorphic trait evolved during a recent radiation in this taxon.

Genetic drift does not sufficiently explain patterns of electric signal variation among populations of the mormyrid electric fishParamormyrops kingsleyae

“…2010; Nagel et al. 2018a,b). Among Paramormyrops species, field and laboratory playback experiments have also revealed strong preferences for species‐specific EOD waveforms during courtship (Hopkins and Bass 1981), indicating that EODs are most likely involved in maintaining prezygotic isolation between closely related species.…”

Electroreception, electrogenesis and electric signal evolution

“…Moreover, both groups occur in high-diversity assemblages comprising species with speciescharacteristic EODs. Studies of electric signal diversity in the mormyroids and gymnotiforms are consequently yielding increasingly powerful insights into the mechanisms of signal and receptor evolution, reproductive isolation and speciation (Arnegard et al, 2010a;Carlson et al, 2011;Crampton et al, 2011;Crampton & Albert, 2006;Feulner et al, 2009aFeulner et al, , 2009bHopkins, 1999a;Nagel et al, 2018b;Picq et al, 2016;Rodríguez-Cattaneo et al, 2008).…”

“…different waveform shape. Furthermore, playback experiments suggest that EOD waveform shape may be the dominant cue for discrimination of conspecifics from heterospecifics in sympatric mormyrids (Arnegard et al, 2006;Hopkins & Bass, 1981;Nagel et al, 2018b).…”

Electro‐Stimulation, a Promising Therapeutic Treatment Modality for Tissue Repair: Emerging Roles of Sulfated Glycosaminoglycans as Electro‐Regulatory Mediators of Intrinsic Repair Processes

“…In this case, the electrical signals emitted by these fish identify individuals and the amplitude and frequency of the emissions can be used to determine their status within the hierarchy of their social group or even the level of sexual maturity of individuals within the group. [ 58 ] Thus, in this context, these electrical emissions serve as a social communication system. [ 59 ]…”