01772nas a2200145   4500008004100000022001400041245018700055210006900242260001200311300001200323490000700335520121500342100001801557856005101575       2013                        eng d  a1727-936400aMorphological and electrophysiological field observations on electric freshwater fish of the genus <i>Mormyrops</i> Müller 1843 (Teleostei: Mormyridae) from West and southern Africa0 aMorphological and electrophysiological field observations on ele  c11/2013  a31 - 410 v383 a<p>Different specimens of Mormyrops anguilloides (Linnaeus 1758) were reported to display electric organ discharge (EOD) pulses of either initially head-positive or initially negative polarity, a hypothetical sex difference that has not been substantiated to date. The morphology and EODs of M. anguilloides of both sexes and a sexually mature size from the Comoé and Bandama rivers, Côte d&rsquo;Ivoire, and the Lower and Middle Zambezi, Mozambique, displayed initially positive EODs. The morphologically similar M. breviceps Steindachner 1895 of both sexes and a sexually mature size from the Bandama River displayed initially head-negative EODs of biphasic waveform and long duration (0.93&ndash;1.15 ms) in the very-low-frequency spectral range. Mormyrops anguilloides from the Comoé and Bandama rivers were differentiated in caudal peduncle depth and in EOD waveform, pulse duration and spectral energy content. The former samples displayed a biphasic, lower-frequency EOD pulse of up to 0.42 ms duration, the latter a tetraphasic, high-frequency EOD of up to 0.33 ms. It is suggested that reports of EODs of both polarities in M. anguilloides indicate the presence of an unrecognised species.</p>
1 aKramer, Bernd  uhttp://dx.doi.org/10.2989/16085914.2013.791244