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.2024.102485