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: ...

First species description of Araneothrombium Mąkol, Felska and Król, 2017 (Trombidiformes: Microtrombidiidae) parasitizing spiders in Brazil

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First species description of Araneothrombium Mąkol, Felska and Król, 2017 (Trombidiformes: Microtrombidiidae) parasitizing spiders in Brazil

ABSTRACT

Microtrombidiidae is one of the most diverse families in the Parasitengona, with more than 120 genera and 400 species. The genus Araneothrombium was originally described from larvae parasitizing juvenile orchard orbweaver spiders (Tetragnathidae) in Costa Rica. To date, there are no records of microtrombidiid mites associated with Brazilian spiders. This study reports the first larval description of Araneothrombium parasitizing three different families (Araneidae, Salticidae, Sparassidae) of juvenile spiders in the state of Rio de Janeiro, Brazil. Herein, a new species, Araneothrombium brasiliensis Bassini-Silva, Welbourn and Jacinavicius n. sp., is described. This discovery expands the known distribution of the genus Araneothrombium, which was previously only recorded in Costa Rica, to now also include Brazil. With this new record, the genus is confirmed to occur in at least two countries in the Neotropical region. The morphological characteristics of the new species were analysed using light and scanning electron microscopy, providing insights into its morphology.

Bassini-Silva, R., Welbourn, C., Ochoa, R., Brescovit, A. D., & de Castro Jacinavicius, F. (2025). First species description of Araneothrombium Mąkol, Felska and Król, 2017 (Trombidiformes: Microtrombidiidae) parasitizing spiders in Brazil. International Journal of Acarology, 1–7. https://doi.org/10.1080/01647954.2025.2566344