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Horka, P.

Publications and source records attributed to Horka, P..

2 recordsLinked to original sources

Unsupervised Approach for Electric Signal Separation in Gnathonemus petersii: Linking Behavior and Electrocommunication

The transfer of information between individuals is fundamental to living systems. Therefore, communication should be studied in various species. Weakly electric fish, Gnathonemus petersii, provides a unique model organism for such investigations due to its advanced electrocommunication capabilities, using electric organ discharges (EODs). Separating EODs from multiple individuals is crucial yet challenging. To remediate it, we developed an unsupervised algorithm for EOD separation in two free-swimming individuals. Using continuous wavelet transform, t-distributed Stochastic Neighbor Embedding, and hierarchical clustering, we achieved accurate discrimination of EODs without the necessity of any training data. This approach overcomes the supervised algorithms based on previously published methods in accuracy and computational efficiency, simplifies experimental procedures, and supports animal well-being by reducing the number of required measurements. Additionally, we introduced a novel technique to map electric signals onto auditory representations, facilitating intuitive analysis of EOD sequences. These advancements lay the groundwork for future studies of EOD-based communication, highlighting the potential of Gnathonemus petersii in neuroethological, psychopharmacological, and translational research.

animal behavior and cognition↗

Trophic niche differentiation in the African elephant fish community (Mormyridae) from the Sanaga River in Cameroon

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 (Cameroon) using the stable isotopes of carbon and nitrogen of muscles and of trophic prey samples. Albeit mormyrids mainly feed on invertebrates, we found differences in isotope signals and the trophic niche partitioning in the studied species. We further show that species with elongated snout tend to show higher carbon and nitrogen isotope signals, suggesting a potential role of snout shape in their trophic preferences. Furthermore, we found significant differences in isotopic signatures within the Mormyrus genus, highlighting ecological niche diversification among three closely related species. We also report on different isotopic signals between seasons of the year in four species, possibly caused by species migration and/or anthropogenic agricultural activities. Overall, our research presents robust evidence of the trophic niche partitioning within the entire mormyrid species community, shedding light on the enigmatic evolutionary history of these fascinating African fishes.

zoology↗