02411nas a2200241 4500008004100000022001400041245014100055210006900196260001600265300001200281490000900293520162800302653002101930653002701951653001501978653003701993653002002030100001902050700001602069700001402085700001802099856005202117 2025 eng d a2658-351800aLength-weight relationships and condition factors of Mormyridae species in the Niger River: implications for conservation and management0 aLengthweight relationships and condition factors of Mormyridae s cJan-01-2025 a215-2210 v20253 a

The length-weight relationship and condition factor of the ten most abundant Mormyridae species in the Niger River at Niamey were examined from August to November 2023. The species assessed were Mormyrus rume, Campylomormyrus tamandua, Pollimyrus isidori, Brienomyrus niger, Hyperopisus bebe, Mormyrus macrophthalmus, Mormyrops anguilloides, Brevimyrus niger, Mormyrops oudoti, Cyphomyrus Psittacus, and Marcusenius cyprinoides. Analysis of their length-weight relationships revealed “b” values ranging from 2.08 to 2.87, suggesting negative allometric growth across all species. Condition factor (k) values varied from 1.22 ± 0.31 for H. bebe to 10.48 ± 2.83 for M. cyprinoides, with no significant differences in average condition factors among the species. These findings highlight the potential vulnerability of Mormyridae species to environmental changes and anthropogenic pressures, emphasizing the need for targeted conservation measures. The results underscore the importance of sustainable fisheries management practices to preserve biodiversity and ensure the long-term productivity of the Niger River ecosystem. The observed negative allometric growth patterns indicate that environmental conditions may be suboptimal for these species, potentially due to factors such as habitat degradation, water quality issues, or overfishing. Addressing these challenges through habitat restoration and regulatory measures could enhance the resilience of fish populations and support sustainable fisheries.

10acondition factor10alength-weight analysis10aMormyridae10asustainable fisheries management10athe Niger River1 aSouley, S.M.N.1 aHarouna, M.1 aAdo, M.I.1 aYoussoufa, I. uhttps://doi.org/10.31951/2658-3518-2025-a-2-21502377nas a2200277 4500008004100000245015600041210006900197260001800266300001000284490000600294520155800300653001701858653001101875653001201886653001301898653001501911653002101926100001801947700001401965700001501979700001701994700001402011700001602025700001202041856004602053 2024 eng d00aDiet of some fish species of the family Mormyridae (Actinopterygii: Teleostei; Bonaparte, 1831) from the upper Sanaga River, Central Region of Cameroon0 aDiet of some fish species of the family Mormyridae Actinopterygi c31 March 2024 a51-620 v63 a

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 (Günther, 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.

10aBiodiversity10aEbebda10afeeding10aMonatele10aMormyridae10astomach contents1 aAkohogni, MAM1 aMedjo, KE1 aZebaze, TB1 aChiassa, NKA1 aMepa, TCP1 aTiogué, TC1 aFon, ED uhttp://dx.doi.org/10.22034/JAD.2024.6.1.502522nas a2200289 4500008004100000022002500041245007300066210006900139260001600208490000700224520164700231653001401878653002001892653002001912653002101932653003201953100002401985700002502009700002202034700002902056700002402085700002002109700002302129700001802152700002102170856004102191 2024 eng d a2045-7758, 2045-775800aTrophic ecology of the African riverine elephant fishes (Mormyridae)0 aTrophic ecology of the African riverine elephant fishes Mormyrid cAug-01-20240 v143 a

Multiple species of the elephant fishes (Mormyridae) commonly coexist in sympatry in most African tropical rivers and lakes. In this study, we investigated the trophic ecology and potential trophic niche partitioning of eleven mormyrid fish species from the Sanaga River system in Cameroon using the stable isotope composition of carbon and nitrogen in the muscle samples. Albeit most mormyrids mainly feed on invertebrates, we found differences in isotope ratios, and we report signs of the trophic niche partitioning among species. We further found significant differences in isotopic signatures within the Mormyrus genus, suggesting ecological niche diversification among three closely related species. We have also evaluated differences in the isotopic signals between seasons in four species, which could be possibly caused by species migration and/or anthropogenic agricultural activities. To evaluate body shape, we applied geometric morphometric analyses, and we show that most of the species are clearly morphologically separated. We focused on the mormyrid ecomorphology to identify a possible interaction between shape and ecology, and we found a relationship between the δ13C (but not δ15N) isotopic signal and morphology, suggesting their interplay during mormyrid evolution. Overall, we present robust evidence of the trophic niche partitioning within the mormyrid species community, and we integrate trophic ecology with morphometrics, shedding light on the enigmatic evolutionary history of these fascinating African fishes.

10amormyrids10astable isotopes10atrophic ecology10atrophic position10atrophic resource portioning1 aSommer, Gina, Maria1 aNjom, Samuel, Didier1 aIndermaur, Adrian1 aNyom, Arnold, Roger Bitj1 aJandová, Kateřina1 aKukla, Jaroslav1 aPetrtýl, Miloslav1 aHorká, Petra1 aMusilova, Zuzana uhttp://dx.doi.org/10.1002/ece3.7017300461nas a2200109 4500008004100000245009000041210006900131260007900200490000700279100001300286856005200299 1976 eng d00aExploration du Parc National de l'Upemba Mission G.F. De Witte, Fascicule 73 Poissons0 aExploration du Parc National de lUpemba Mission GF De Witte Fasc aBrusselsbFondation Pour Favoriser Les Recherches Scientifiques en Afrique0 v731 aPoll, M. uhttps://mormyrids.efishgenomics.com/fr/node/63300469nas a2200133 4500008004100000245010400041210007000145300001200215490000700227100001500234700001500249700002000264856005100284 1973 eng d00aContribution a l’étude de la faune ichthyologique du bassin du fleuve Sénégal. III. Mormyridae0 aContribution a l étude de la faune ichthyologique du bassin du f a665-7040 v351 aReizer, C.1 aMattei, X.1 aChevalier, J.L. uhttps://mormyrids.efishgenomics.com/fr/node/98