Distinct pathophysiological mechanisms of Heterometrus laoticus and Lychas mucronatus scorpion venoms on cardiovascular and renal functions

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  Distinct pathophysiological mechanisms of Heterometrus laoticus and Lychas mucronatus scorpion venoms on cardiovascular and renal functions Abstract Background:    Heterometrus laoticus and Lychas mucronatus are widely distributed in Southeast Asia, yet their pathophysiological effects of both venoms remain poorly characterized due to low human fatality rates. This study compared their venom compositions and acute cardiovascular and renal effects. Methods:   Anesthetized male New Zealand White rabbits were monitored for blood pressure (BP), heart rate (HR), and renal clearance following intravenous administration of crude venom (0.5 mg/kg). Venom components were identified via LC-MS/MS, and hematological/biochemical parameters were assessed. Results:    H. laoticus venom induced a rapid, transient hypotension ( p < 0.05), followed by a mild, prolonged hypotensive phase (up to 120 min). Conversely, L. mucronatus venom elicited a biphasic response: ...

The agrobiont wolf spider, Tigrosa helluo (Araneae: Lycosidae), has broad thermal limits and displays consistent temperature preferences in laboratory trials

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The agrobiont wolf spider, Tigrosa helluo (Araneae: Lycosidae), has broad thermal limits and displays consistent temperature preferences in laboratory trials

Abstract

The arthropod species that invade and persist in disturbed habitats, such as agricultural fields, likely have adaptations that allow individuals to tolerate and/or respond to abiotic extremes. We hypothesized that the agribiont wolf spider, Tigrosa helluo (Walckenaer, 1837) (Araneae, Lycosidae), would have a broad thermal tolerance range and be able to actively select favorable sites within an open landscape. We documented the reactions of juveniles and adult females when released in a hostile arena at low (4 to 7 °C), high (77 to 80 °C), or room temperatures (23 to 26 °C) and recorded the temperature where they settled as a measure of thermal preference. All individuals commenced moving in less than a minute and repeatedly relocated to regions with more amenable temperatures (≈ 20 °C) regardless of their starting point. We also determined the critical thermal maxima (CTmax) and minima (CTmin) of the subjects. The CTmax for adults was between 37 to 48 °C which was significantly higher than the values of 27 to 46 °C obtained for juveniles. The CTmin for adults was 2 to 6 °C which was significantly lower than we recorded for juveniles (between 2 and 7 °C). Taken together, the broad tolerance range, quick reactions to temperature extremes, and consistent thermal preferences displayed by T. helluo likely contribute to their success in disturbed agroecosystems. Both adult females and juveniles can withstand the thermal environment for much of the year and counter extreme temperatures through behavior.


Sperry, M., Shannon, H. C., & Rypstra, A. L. The agrobiont wolf spider, Tigrosa helluo (Araneae: Lycosidae), has broad thermal limits and displays consistent temperature preferences in laboratory trials. Environmental Entomology. https://doi.org/10.1093/ee/nvaf053


Acknowledgment: I sincerely thank Leif Cash (@leifcollectsbugs) for generously providing the in situ image of Tigrosa helluo.