Harvestmen (Arachnida: Opiliones) as Overlooked Predators of Anurans in the Neotropics

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  Harvestmen (Arachnida: Opiliones) as Overlooked Predators of Anurans in the Neotropics ABSTRACT Arthropods are traditionally viewed as invertebrate prey and as predators of other invertebrates, whereas vertebrates are typically considered their predators. However, this paradigm has increasingly been challenged, particularly among arachnids. While several invertebrates are well documented as frog predators, the capacity of particular groups, such as harvestmen (Opiliones), to prey on vertebrates has remained largely anecdotal. Here we report novel field observations of anuran predation by multiple Cranaidae harvestman species across several Neotropical localities. These records include the active capture and consumption of live frogs, demonstrating their role as opportunistic mesopredators. Our findings expand current knowledge of Opiliones ecology by confirming that vertebrate predation occurs across multiple species and localities. Our results suggest that vertebrate consumption...

Exploring the antiangiogenic effects of Phospholipases A2 from Bothrops diporus venom

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Exploring the antiangiogenic effects of Phospholipases A2 from Bothrops diporus venom

Abstract

Angiogenesis, the formation of new blood vessels from pre-existing vasculature, is a crucial process in both physiological and pathological contexts, including cancer. Phospholipases A2 (PLA2s), enzymes found in snake venoms, have attracted attention due to their potential antiangiogenic properties. In this study, we explored the antiangiogenic effects of PLA2 isoforms isolated from Bothrops diporus venom using a combination of in vivo and ex vivo models. The chorioallantoic membrane (CAM) assay revealed a significant reduction in vascular density and branching following PLA2s treatment, with histological analysis confirming vascular regression, including vessel wall thinning and luminal collapse. Moreover, PLA2s induced endothelial cell apoptosis, as shown by TUNEL staining, and reduced VEGF expression. The filter paper disc variant of the CAM assay further supported these findings, demonstrating inhibited neovascularization while preserving mature vessels. Additionally, the CAM explant assay showed a marked decrease in vascular complexity and branching. These results demonstrate the antiangiogenic effect of PLA2 isoforms from B. diporus and suggest that these enzymes may modulate key angiogenic pathways. Based on our previous findings, this modulation may involve interference with integrin-mediated signaling, which could underlie the vascular effects observed. Thus, this work provides compelling evidence for the potential role of snake venom-derived PLA2s in modulating angiogenesis and highlights the need for further research into their mechanisms and possible biomedical applications.

Sasovsky, D.J., Olea, G.B., Ojeda, G. et al. Exploring the antiangiogenic effects of Phospholipases A2 from Bothrops diporus venom. Cell Tissue Res (2025). https://doi.org/10.1007/s00441-025-04008-7