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-2-215