First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes

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  First insights into the role of evolutionary history in shaping venom composition of Vipera ammodytes Abstract Understanding intraspecific venom variation requires distinguishing the contributions of neutral population history from natural selection. This study aims to determine whether venom variation in the Vipera ammodytes species complex is structured across eight phylogenetic lineages. Despite a complex evolutionary history, venom composition did not differ among phylogenetic units within the analytical framework used, suggesting that shared ancestry alone does not explain venom variation. Whether local adaptation to environmental conditions explains the observed variation remains an open question for future studies. Lakušić, M., Piccoli, C., Anđelković, M., Andonov, K., Burić, I., Brito, J. C., Dyugmedzhiev, A., Merdan, S., Schmid, L., Tzoras, E., Florian-Hempel, B., & Martínez-Freiría, F. (2026). First insights into the role of evolutionary history in shaping venom co...

Offspring Defensive Investment Covaries With Brood Value in a Female Cobweb Spider

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Offspring Defensive Investment Covaries With Brood Value in a Female Cobweb Spider


ABSTRACT

Maternal investment in offspring defense is expected to enhance offspring survival and parental reproductive success. In cobweb spiders that construct detritus-based, bell-shaped retreats, these structures serve to protect the spiderling. The brood value hypothesis predicts that such defensive investment should be proportional to brood value (e.g., egg sac mass and number). We tested this hypothesis in the cobweb spider Campanicola campanulata by conducting field measurements of retreat architecture and maternal defensive investment in relation to egg sac presence, weight, and total grains. As predicted, females with egg sacs constructed larger retreats, and investment increased with both egg sac mass and egg count. These results support the brood value hypothesis and highlight retreat architecture as a crucial yet understudied component of parental care in spider.

Zhang, H., J. Liu, C. Li, et al. 2026. “ Offspring Defensive Investment Covaries With Brood Value in a Female Cobweb Spider.” Integrative Zoology. https://doi.org/10.1111/1749-4877.70160