Venom composition of the Iberian adder (Vipera seoanei) from northern Portugal reveals limited sex and size variation

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  Venom composition of the Iberian adder (Vipera seoanei) from northern Portugal reveals limited sex and size variation Abstract Snake venom is a complex and dynamic ecological trait, with high potential for intraspecific variation. In this study, the venom composition of the Iberian adder ( Vipera seoanei ) from the Peneda Mountains of northern Portugal was investigated to explore whether venom varies with body size and sex. Venom proteomes from six individuals representing juvenile, subadult, and adult males and females were characterised using LC–MS/MS, while individual variation was assessed from SDS–PAGE profiles of 18 snakes. LC–MS/MS identified 144 proteins, dominated by phospholipases A 2 (PLA 2 ), snake venom serine proteases (svSP), and C-type lectin-related proteins (CTL). Descriptive comparisons revealed contrasting individual profiles, particularly between the juvenile male, characterised by high svSP and svMP abundance, and the juvenile female, characterised by high ...

Diversification of Dolichothele mottai (Araneae: Theraphosidae), a Cerrado endemic tarantula

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Diversification of Dolichothele mottai (Araneae: Theraphosidae), a Cerrado endemic tarantula

Abstract

The Cerrado is a savannah domain occurring along the Central Brazilian Plateau and is a biodiversity hotspot. Two main hypotheses have been suggested in the study of lineage diversification in this domain. The first suggests that Pleistocene climatic fluctuations isolated populations of species in refugia, leading to their diversification. The second considers geomorphological or ecological processes in the Neogene as the main drivers of diversification in the Cerrado. Here, the first phylogeographical study of a Cerrado endemic spider, Dolichothele mottai, was conducted to test these diversification hypotheses, using genomic and mitochondrial data combined with tests of demographic models. Dolichothele mottai lineages diversified in the Mio-Pliocene, and a pattern of east–west genetic structuring along Central Cerrado plateaus was identified. Vicariance was the preferred model in demographic analysis, and geomorphological events in the Araguaia River Valley region during the Mio-Pliocene might have been relevant to the evolutionary history of this species. However, owing to demographic analyses, the influence of Pleistocene processes cannot be discarded as a possible hypothesis to explain lineage diversification in this species. Diversification patterns inferred here are concomitant with other Central Cerrado animal lineages, suggesting that processes in the Neogene influenced the diversification of phylogenetically distant groups.

Vespasiano, C. T., Serino-Silva, C., Machado Silveira, G. P., Rodrigues, F. S., Rameh-de-Albuquerque, L. C., Sant'anna, S. S., Grego, K. F., & Tanaka-Azevedo, A. M. (2025). Investigating the Influence of Hepatic Neoplasms on Bothrops Venom Biochemistry. Toxicon, 108561. https://doi.org/10.1016/j.toxicon.2025.108561