02056nas a2200241 4500008004100000022001400041245014300055210006900198260001600267300001100283520124300294653003801537653002201575653001801597653001801615653001501633653002801648100002401676700001801700700002301718700002401741856004901765 2024 eng d a0380-133000aBiogeographic barriers are differentially permeable based on traits: Movement of hypoxia tolerant mormyrid fish in the Lake Victoria basin0 aBiogeographic barriers are differentially permeable based on tra cNov-01-2024 a1024853 a

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.

10aDifferentially permeable barriers10aHypoxia tolerance10aLake Nabugabo10aLake Victoria10aMormyridae10aPopulation connectivity1 aHunt, David, A.G.A.1 aThomas, Quinn1 aClarke, Shelby, B.1 aChapman, Lauren, J. uhttp://dx.doi.org/10.1016/j.jglr.2024.10248502377nas 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.2024.6.1.5