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Electrocommunication in pulse Gymnotiformes: the role of EOD time course in species identification.
Author(s) -
Joseph C. Waddell,
Ángel A. Caputi
Publication year - 2020
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.226340
Subject(s) - electroreception , electric fish , electric organ , signal (programming language) , biology , pulse (music) , waveform , electric field , amplitude , communication , fish <actinopterygii> , computer science , physics , telecommunications , psychology , optics , receptor , fishery , programming language , biochemistry , radar , torpedo , acetylcholine receptor , quantum mechanics , detector
Understanding how individuals detect and recognize signals emitted by conspecifics is fundamental to discussions of animal communication. The species pair Gymnotus omarorum and Brachyhypopomus gauderio, found in syntopy in Uruguay, emit species-specific electric organ discharges that can be sensed by both species. The aim of this study was to unveil whether either of these species are able to identify a conspecific electric organ discharge, and to investigate distinctive recognition signal features. We designed a forced-choice experiment using a natural behavior (i.e. tracking electric field lines towards their source) in which each fish had to choose between a conspecific and a heterospecific electric field. We found a clear pattern of preference for a conspecific waveform even when pulses were played within 1 Hz of the same rate. By manipulating the time course of the explored signals, we found that the signal features for preference between conspecific and heterospecific waveforms were embedded in the time course of the signals. This study provides evidence that pulse Gymnotiformes can recognize a conspecific exclusively through species-specific electrosensory signals. It also suggests that the key signal features for species differentiation are probably encoded by burst coder electroreceptors. Given these results, and because receptors are sharply tuned to amplitude spectra and also tuned to phase spectra, we extend the electric color hypothesis used in evaluation of objects to apply to communication signals.