@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 {485, title = {Differences in electrosensory anatomy and social behavior in an area of sympatry between two species of mormyrid electric fishes}, journal = {Journal of Experimental Biology}, volume = {219}, year = {2016}, month = {Apr-11-2016}, pages = {31 - 43}, abstract = {

Sensory systems play a key role in social behavior by mediating the detection and analysis of communication signals. In mormyrid fishes, electric signals are processed within a dedicated sensory pathway, providing a unique opportunity to relate sensory biology to social behavior. Evolutionary changes within this pathway led to new perceptual abilities that have been linked to increased rates of signal evolution and species diversification in a lineage called \‘clade A\’. Previous field observations suggest that clade-A species tend to be solitary and territorial, whereas non-clade-A species tend to be clustered in high densities suggestive of schooling or shoaling. To explore behavioral differences between species in these lineages in greater detail, I studied population densities, social interactions, and electric signaling in two mormyrid species, Gnathonemus victoriae (clade A) and Petrocephalus degeni (non-clade A), from Lwamunda Swamp, Uganda. Petrocephalus degeni was found at higher population densities, but intraspecific diversity in electric signal waveform was greater in G. victoriae. In the laboratory, G. victoriae exhibited strong shelter-seeking behavior and competition for shelter, whereas P. degeni were more likely to abandon shelter in the presence of conspecifics as well as electric mimics of signaling conspecifics. In other words, P. degeni exhibited social affiliation whereas G. victoriae exhibited social competition. Further, P. degeni showed correlated electric signaling behavior whereas G. victoriae showed anti-correlated signaling behavior. These findings extend previous reports of social spacing, territoriality, and habitat preference among mormyrid species, suggesting that evolutionary divergence in electrosensory processing relates to differences in social behavior.

}, issn = {0022-0949}, doi = {10.1242/jeb.127720}, url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.127720}, author = {Bruce A Carlson} } @article {262, title = {Zoological results of the George Vanderbilt African Expedition of 1934. Part III,{\textendash}The fresh water fishes}, journal = {Proceedings of the Academy of Natural Sciences of Philadelphia}, volume = {88}, year = {1936}, month = {07/1936}, pages = {243{\textendash}335}, abstract = {

The Academy is fortunate in securing the very interesting collection obtained by this expedition. Considering the wide range of localities or stations across transcontinental Africa, of which 39 are listed in part 1 of the present series of papers,\’ only 7 yielded fishes. These are: (13) Athi River Crossing, (17) Kitala, (23) Saidi\’s Village, (24) Vube, (26) Eki- bondo\’s Village, (27) Fort Sibut and (33) Nola. Other smaller lots of materials were later received from 30 kilometers east of Kribi, Cameroons, and Batangafo, Chad Basin. The specimens number nearly 3000, representing 115 species, of which 10 are described as new genera or subgenera and 36 as new species or sub- species. This is surely a remarkable showing, especially in view of the comparatively short amount of time available and the mobility of the expedition. To Mr. George Vanderbilt is due special acknowledgment for his per- sonal interest in the collecting of the specimens, and amassing comprehen- sive series for the museum of the Academy.

}, author = {Fowler, H.W.} } @article {677, title = {New species of fish from the Albert Nyanza and Lake Kioga}, journal = {Proceedings of the General Meetings for Scientific Business of the Zoological Society of London Pt. 3}, volume = {99}, year = {1929}, month = {10/1929}, pages = {429{\textendash}440}, author = {Worthington, E.B.} } @book {159, title = {The Mormyridae and other Osteoglossomorpha (CD-ROM)}, series = {World Biodiversity Database, CD-ROM Series}, volume = {2000}, year = {2000}, publisher = {Springer Verlag, ETI-UNESCO}, organization = {Springer Verlag, ETI-UNESCO}, address = {New York}, issn = {Hyb: 3-540-14811-6}, url = {https://www.amazon.com/Mormyridae-Osteoglossomorpha-Biodiversity-Database-CD-ROM/dp/3540148116}, author = {Harder, W.} }