01729nas a2200193 4500008004100000245015000041210006900191300001000260490000700270520108100277653002901358653001201387653003001399653001501429653001501444653001201459100001501471856004901486 1989 eng d00aDistribution, abundance, size and feeding habits of Brienomyrus brachyistius (Gill, 1862) (Teleostei: Mormyridae) in a Nigerian rainforest stream0 aDistribution abundance size and feeding habits of Brienomyrus br a25-360 v133 a

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.

10aBrienomyrus brachyistius10aecology10aHydrometeological regimes10aIkpa River10aMormyridae10aNigeria1 aKing, R.P. uhttps://doi.org/10.26028/cybium/1989-131-00302046nas a2200229 4500008004100000022001400041245010400055210006900159260001600228300001100244520130700255653001201562653003001574653002801604653001501632653001901647653001501666100001801681700002901699700001801728856007001746 2016 eng d a1608-591400aMarcusenius desertus sp. nov. (Teleostei: Mormyridae), a mormyrid fish from the Namib desert0 aiMarcusenius desertusi sp nov Teleostei Mormyridae a mormyrid fi cJul-03-2016 a1 - 183 a

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.

10aecology10aelectric organ discharges10agenetic differentiation10amorphology10aphylogeography10aspeciation1 aKramer, Bernd1 avan der Bank, F., Herman1 aWink, Michael uhttp://www.tandfonline.com/doi/full/10.2989/16085914.2015.1137855