Behavioral interactions between sexes in the critically endangered annual killifish Leptopanchax itanhaensis (Cyprinodontiformes, Rivulidae)
DOI:
https://doi.org/10.37002/biodiversidadebrasileira.v16i2.2914Keywords:
Atlantic Forest , Intersexual behavior, Courtship, Mate choice, Body sizeAbstract
We provide the first quantitative description of intersexual behavioral interactions in the critically endangered annual killifish Leptopanchax itanhaensis, aiming to characterize its behavioral repertoire, sex-specific expression of behaviors, and variation associated with couple size. Behavioral observations were conducted on seven couples sampled from a roadside ditch in the coastal Atlantic Forest of southeastern Brazil. Behavioral frequencies were recorded during standardized observation periods, converted to relative proportions, and analyzed using generalized linear mixed models to test for sex differences in total behavioral activity and behavioral diversity while accounting for couple identity. Behavioral composition varied markedly among couples and across size classes. Resting in the bottom was the most frequent behavior in both sexes, while courtship-related behaviors were more prevalent in larger couples. Total behavioral activity and behavioral diversity did not differ significantly between sexes. However, males more frequently exhibited courtship and harassing behaviors, whereas females more frequently exhibited being courted and escape behaviors. These findings provide the first behavioral baseline for this critically endangered species and highlight the importance of behavioral studies for understanding habitat use and reproductive interactions in annual killifishes.
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Copyright (c) 2026 João Henrique Alliprandini da Costa, Victor Monteiro Zanette, Ana Giulia Stefanelli Biussi, Amanda Selinger
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