From Scorpion Venom to Infection Research: The Promise of Opis16a (Blog Entry)

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  Opistophthalmus carinatus , a southern African scorpion whose venom contains opistoporin 1, the parent peptide from which researchers derived the shorter antimicrobial peptide Opis16a. Credit: Dan Lee / CC0 1.0 From Scorpion Venom to Infection Research: The Promise of Opis16a A synthetic peptide inspired by a southern African scorpion’s venom shows activity against drug-resistant bacteria—but its potential as a wound treatment remains under investigation. Scorpion venom is a complex mixture of biologically active molecules. While many are studied for their effects on ion channels and the nervous system, others offer a different research opportunity: understanding how peptides can damage bacterial cells. One such candidate is Opis16a , a synthetic, 16-amino-acid fragment derived from opistoporin 1, a peptide originally isolated from the venom of Opistophthalmus carinatus . Research highlighted by Nature Africa suggests that this shortened molecule combines broad antibacterial acti...

Locomotor behaviour of tropical wolf spiders is affected by external temperature and body size, not load bearing

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Locomotor behaviour of tropical wolf spiders is affected by external temperature and body size, not load bearing

Ectothermic animals depend on ambient temperature to regulate internal temperature. This dependence affects many aspects of their behaviour, including locomotion, foraging and reproduction. Additionally, ectotherms are more vulnerable in environments with extreme hourly temperature fluctuations and their activity patterns likely match those of favourable temperatures. Here, we studied Pardosa wolf spiders (Lycosidae) in the highland tropical paramos of Costa Rica. We tested two hypotheses to elucidate the factors that influence variation in locomotor behaviour. First, we tested whether locomotor behaviour is driven by temperature variation. Female spiders experimentally exposed to higher temperatures (30 °C) moved approximately four times faster than those exposed to lower temperatures (7 °C). Second, we tested whether locomotor behaviour is modulated by the maternal care strategy of these spiders. Females carry an eggsac externally by holding it with the distal spinnerets. The eggsac can represent up to 36% of the spider's body size. However, females moved at the same speed regardless of whether they carried an eggsac or not. This demonstrates that the maternal care strategy does not affect their locomotor performance. In contrast, temperature plays a crucial role in driving locomotion. Our findings expand our understanding of how temperature fluctuations in extreme environments challenge ectotherms’ ability to move and, by extension, escape predators and locate mates and food.

Damián Villaseñor-Amador, Leonardo Vilas-Bôas M.P. de Cerqueira, Quimey Gómez, Francisca Zamora Cornejo, Julia Paulucci, Ignacio Escalante, Locomotor behaviour of tropical wolf spiders is affected by external temperature and body size, not load bearing, Animal Behaviour, 2023, ISSN 0003-3472, https://doi.org/10.1016/j.anbehav.2023.10.003.