@article {665, title = {Distribution, abundance, size and feeding habits of Brienomyrus brachyistius (Gill, 1862) (Teleostei: Mormyridae) in a Nigerian rainforest stream}, journal = {Cybium}, volume = {13}, year = {1989}, pages = {25-36}, chapter = {25}, abstract = {

Brienomyrus brachyistius (Gill, 1862) constitutes 64\% of the total number of all mormyrid species caught from the upper and middle reaches of Ikpa River in the rainforest zone of south-eastern Nigeria. It inhabits shallow marginal areas and swamp-pools with aquatic macrophytes. B. brachyistius\ feeds primarily on benthic invertebrates (with chironomid larvae predominating), algae, detritus and secondarily on zooplankton, miscellaneous invertebrates and mud/sans; allochthonous invertebrates and macrophyte material are of incidental importance. The diet varies slightly with growth and season. Feeding activity is higher in the small-sized guild (\< 10 cm TL) than large-sized guild (\≥ 10 cm TL); it is intense at night but declines during the day and is higher in the dry season than during the rains. Seasonal fluctuations in hydrometeorological regimes (rainfall, water level, flow rate) are critical factors that affect the food and feeding habits of the fish; flood has a depressive influence on food variety and feeding intensity.

}, keywords = {Brienomyrus brachyistius, ecology, Hydrometeological regimes, Ikpa River, Mormyridae, Nigeria}, doi = {10.26028/cybium/1989-131-003}, url = {https://doi.org/10.26028/cybium/1989-131-003}, author = {King, R.P.} } @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} }