@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 {664, title = {Biogeographic barriers are differentially permeable based on traits: Movement of hypoxia tolerant mormyrid fish in the Lake Victoria basin}, year = {2024}, month = {Nov-01-2024}, pages = {102485}, abstract = {

Lake Nabugabo is a small satellite lake separated from Lake Victoria by hypoxic swamps that impose a biogeographic barrier to fish assemblages. Some species occur exclusively in Nabugabo while others show high differentiation across this barrier, yet air-breathing fishes show nearly zero genetic differentiation between the two lakes. We hypothesize that hypoxia-tolerant fishes, unlike other non-air-breathing species, would have similarly low genetic differentiation across the barrier. We used pooled RAD-seq to examine the degree of genetic differentiation in two species of non-air-breathing but hypoxia-tolerant mormyrid fishes, Marcusenius victoriae and Petrocephalus degeni. Other non-air-breathing fishes have been shown to have FST values as low as 0.05 but mostly between 0.10 and 0.20; however, we discovered that the genetic differentiation in our focal species was very low, with FST values between 0.02 and 0.04, making them much more comparable to air-breathing fishes with FST values of near zero. We conclude that this and other analogous barriers should be understood as differentially permeable depending on the traits of the organisms crossing them, such as hypoxia tolerance in this case.

}, keywords = {Differentially permeable barriers, Hypoxia tolerance, Lake Nabugabo, Lake Victoria, Mormyridae, Population connectivity}, issn = {0380-1330}, doi = {10.1016/j.jglr.2024.102485}, url = {http://dx.doi.org/10.1016/j.jglr.2024.102485}, author = {Hunt, David A.G.A. and Thomas, Quinn and Clarke, Shelby B. and Chapman, Lauren J.} } @article {660, title = {Diet of some fish species of the family Mormyridae (Actinopterygii: Teleostei; Bonaparte, 1831) from the upper Sanaga River, Central Region of Cameroon}, journal = {Journal of Animal Diversity}, volume = {6}, year = {2024}, month = {31 March 2024}, pages = {51-62}, chapter = {51}, abstract = {

This study was carried out between October 2020 and October 2021 with the aim of determining sustainable management options and nutrition for the domestication of Mormyridae fish species living in the Sanaga River in central Cameroon. For this purpose, 451 specimens collected from local fishermen were identified and grouped into four genera and seven species, constituting 20.84\% Campylomormyrus phantasticus (Pellegrin), 5.32\% Hippopotamyrus castor (Pappenheim), 24.61\% Mormyrops anguilloides (Linnaeus), 18.63\% Mormyrops caballus (Pellegrin), 4.66\% Mormyrops zanclirostris (G\ünther, 1867), 15.52\% Mormyrus rume (Valenciennes), and 10.42\% Mormyrus tapirus (Pappenheim). Fish were measured, and parameters were obtained after dissection using intestinal morphometric characteristics and stomach content analysis methods. The emptiness coefficient varied from 0\% (Hippopotamyrus castor and Mormyrops zanclirostris) to 26.66\% (Mormyrus rume). The relative mass of the intestine was low in all studied species; the intestinal coefficient and the Zihler index of all these species are within the range of carnivorous species. Analysis of stomach contents revealed a broad food spectrum containing twelve categories of prey. Insects, macrophytes and larval insect shelters were the preferred foods of Mormyrops anguilloides, Mormyrops caballus and Mormyrops zanclirostris, while insect larvae and larval shelters were the preferred prey for other species. Site and season had little effect on the categories of prey consumed by these species.

}, keywords = {Biodiversity, Ebebda, feeding, Monatele, Mormyridae, stomach contents}, doi = {10.22034/JAD.2024.6.1.5}, url = {http://dx.doi.org/10.22034/JAD.2024.6.1.5}, author = {Akohogni, MAM and Medjo, KE and Zebaze, TB and Chiassa, NKA and Mepa, TCP and Tiogu{\'e}, TC and Fon, ED} } @article {499, title = {Species delimitation and phylogenetic relationships in a genus of African weakly-electric fishes (Osteoglossiformes, Mormyridae, Campylomormyrus)}, journal = {Molecular Phylogenetics and Evolution}, year = {2016}, month = {Jan-04-2016}, abstract = {

African weakly-electric fishes (Mormyridae) are able to communicate through species-specific electric signals; this feature might have favoured the evolutionary radiation observed in this family (over 200 species) by acting as an effective pre-zygotic isolation mechanism. In the present study we used mitochondrial (cytb) and nuclear (rps7, scn4aa) markers in order to reconstruct a species-phylogeny and identify species boundaries for the genus Campylomormyrus, by applying inference methods based on the multispecies coalescent model. Additionally, we employed 16 microsatellite markers, landmark-based morphometric measurements, and electro-physiological analyses as independent lines of evidence to the results obtained from the sequence data. The results show that groups that are morphologically different are also significantly divergent at the genetic level, whereas morphologically similar groups, displaying dissimilar electric signals, do not show enough genetic diversity to be considered separate species. Furthermore, the data confirm the presence of a yet undescribed species within the genus Campylomormyrus.

}, keywords = {Campylomormyrus, Geometric morphometrics, Microsatellites, Mormyridae, Multispecies-coalescent, Species-delimitation}, issn = {10557903}, doi = {10.1016/j.ympev.2016.04.035}, url = {http://linkinghub.elsevier.com/retrieve/pii/S1055790316300781}, author = {Lamanna, Francesco and Frank Kirschbaum and Ernst, Anja R.R. and Philine G.D. Feulner and Victor Mamonekene and Paul, Christiane and Ralph Tiedemann} }