@article {496, title = {Marcusenius desertus sp. nov. (Teleostei: Mormyridae), a mormyrid fish from the Namib desert}, journal = {African Journal of Aquatic Science}, year = {2016}, month = {Jul-03-2016}, pages = {1 - 18}, abstract = {

We critically compared Marcusenius specimens from the mouth of the Cunene River on the Namibia/Angola border, a harsh desert environment on the Atlantic Ocean coast virtually devoid of aerial insects with aquatic larvae which are an important food item, with Marcusenius multisquamatus Kramer \& Wink, 2013 from the escarpment region of that same river, in a relatively rich and productive subtropical savannah environment. River mouth specimens were differentiated in morphology and electric organ discharges, as determined by ANOVA/MANOVA comparisons, principal component and discriminant analyses on morphological and electrophysiological characters, and genetics, including sequences of the mitochondrial cytochrome b gene, indicating reproductive isolation. Specimens from the river mouth differed from M. multisquamatus, their closest relatives, by having a shorter snout, a smaller eye diameter, and smaller nares separation. River mouth specimens were also differentiated from other, increasingly less-close relatives, such as M. altisambesi Kramer et al., 2007 from the Okavango River, Botswana, and from M. krameri Maake et al., 2014 from the Limpopo System, South Africa. We therefore designate the new species Marcusenius desertus sp. nov. for the Cunene River mouth population.

}, keywords = {ecology, electric organ discharges, genetic differentiation, morphology, phylogeography, speciation}, issn = {1608-5914}, doi = {10.2989/16085914.2015.1137855}, url = {http://www.tandfonline.com/doi/full/10.2989/16085914.2015.1137855}, author = {Bernd Kramer and F. Herman van der Bank and Michael Wink} } @article {852, title = {Morphological and electrophysiological field observations on electric freshwater fish of the genus Mormyrops M{\"u}ller 1843 (Teleostei: Mormyridae) from West and southern Africa}, journal = {African Journal of Aquatic Science}, volume = {38}, year = {2013}, month = {11/2013}, pages = {31 - 41}, abstract = {

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\’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\–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.

}, issn = {1727-9364}, doi = {10.2989/16085914.2013.791244}, url = {http://dx.doi.org/10.2989/16085914.2013.791244}, author = {Bernd Kramer} }