Qualitative and Quantitative Proteomic Analysis of Venoms from Mexican Rattlesnakes

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  Qualitative and Quantitative Proteomic Analysis of Venoms from Mexican Rattlesnakes Abstract Despite the vast biodiversity of Mexican vipers, venom of endemic species has been barely studied. Here we analyzed the venom composition of three endemic species of rattlesnakes: Crotalus aquilus , C. triseriatus , and C. ravus . We used quantitative chromato-mass-spectrometry and compared venoms with C. molossus , a species commonly found in North America, in a comparative and phylogenetic framework. In total, we identified 165 proteins grouped in 19 main protein families, consistent with previous reports for viperid venoms. In C. aquilus and C. triseriatus , the most predominant protein-family type was Serine Proteases, and in C. triseriatus and C. molossus it was Snake Venom Metalloproteases. The Label-free quantification revealed a high proportion of Snake Venom Metalloproteases in C. aquilus , C. triseriatus , and C. molossus , reaching 28–47% of the total venom. In contrast, in ...

Predation of the slender opossum Marmosops caucae (Didelphimorphia, Didelphidae) on the venomous spider Phoneutria fera (Araneae: Ctenidae) in Amazonian Ecuador, with a dietary overview for the genus Marmosops

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Predation of the slender opossum Marmosops caucae (Didelphimorphia, Didelphidae) on the venomous spider Phoneutria fera (Araneae: Ctenidae) in Amazonian Ecuador, with a dietary overview for the genus Marmosops

Abstract

Small marsupials of the genus Marmosops are widely regarded as omnivore-insectivores, but quantitative information on their diets is fragmentary. Here, we report the first verified predation event of the highly venomous wandering spider Phoneutria fera by Marmosops caucae during a nocturnal survey in Amazonian Ecuador, and provide the most comprehensive synthesis to date of prey use within the genus, based on a literature review and participatory science observations. The synthesis yielded nine primary studies and three iNaturalist records offering diet data for six Marmosops species. Collectively, these records encompass 15 invertebrate orders and five vertebrate classes; Coleoptera and Hymenoptera dominate, whereas large arachnids occur only sporadically. The breadth and composition of prey spectra are best explained by local availability rather than dietary specialisation, underscoring the genus's behavioural flexibility. Our observation expands the known trophic interactions of Marmosops and highlights the need for experimental work on venom tolerance and potential ecological effects on spider guilds.
Guerrero-Campoverde, A., Viteri-Basso, E., Peñaherrera-R., P., & Cisneros-Heredia, D. F. (2025). Predation of the slender opossum Marmosops caucae (Didelphimorphia, Didelphidae) on the venomous spider Phoneutria fera (Araneae: Ctenidae) in Amazonian Ecuador, with a dietary overview for the genus Marmosops. Food Webs, e00418. https://doi.org/10.1016/j.fooweb.2025.e00418