Geographically separated orange and blue populations of the Amazonian poison frog Adelphobates galactonotus (Anura, Dendrobatidae) do not differ in alkaloid composition or palatability
As is typical of chemically defended animals, poison frogs present high variability in their alkaloid-based defenses. Previous studies have shown that geographically separated color morphs of Oophaga and Dendrobates species differ in both alkaloid composition and arthropod palatability. Here, we tested the generality of that finding by studying the alkaloid composition and palatability of geographically separated blue and orange morphs of the splash-backed poison frog, Adelphobates galactonotus. We identified and quantified the alkaloid composition of each individual frog using gas chromatography–mass spectrometry and evaluated the palatability of individual secretions to arthropods conducting feeding trials with Drosophila melanogaster. Despite their conspicuous differences in color and separation on opposite sides of a large aquatic barrier, the two morphs did not differ in alkaloid composition or palatability. This result shows that both color morphs are equally chemically protected and suggests that the color variation is not driven by predator selection.
KeywordsAposematism Chemical defense GC–MS Polychromatism Polytypism
We thank M. Rada, J.J. Ospina-Sarria, C.A. Lopes, S. Andrade, the São Sebastião and Vila do Bravo communities, and the crew of Estação Científica Ferreira Penna (Museu Paraense Emílio Goeldi, Universidade Federal do Pará) for assistance during fieldwork. Specimen collection (license numbers 13173-2 and 54640-1) and export (authorization number 17BR025049/DF) permits were issued by Instituto Chico Mendes de Conservação da Biodiversidade (ICMBIO)/Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA). This study was approved by the Ethics Committee on Animal Use of the Institute of Biosciences, University of São Paulo (CEUA Protocol 268/2016). We thank M. Nichols for his assistance in maintaining the GC–MS and Kresge Foundation and Colleran-Weaver for funding. This research was supported by the Brazilian Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Proc. 306823/2017-9) and Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP Proc. 2012/10000-5, 2016/09999-9, 2018/15425-0).
AMJ, RAS, and TG contributed to the study conception and design. Specimens were collected by AMJ and TG. Chemical analysis was performed by AMJ and RAS. Palatability tests were performed by SK and RAS. The first draft of the manuscript was written by AMJ and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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