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

Posted by
  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: ...

Flexible foraging and mating behaviours in an orb weaver

Posted by

 


Flexible foraging and mating behaviours in an orb weaver

Abstract


The evolution of the orb web was associated with a major radiation in spider diversity. Orb webs evolved for prey capture, and they also play important roles in courtship and mating. However, the construction and use of orb webs has associated costs, and the modification and loss of orb webs have evolved multiple times. While variation between species is evident, such as reductions or loss of the orb web for foraging, this kind of variation is rarely detailed within species. Here, I describe laboratory observations of foraging and mating without an orb web in a typical orb-weaving spider, the Australian garden orb weaver (hortophora biapicata). The behavioural range observed here shows the natural variation in these traits, on which selection might act to drive the reduction or loss of orb webs. Further investigation of these rare and unusual behaviours can help us understand the function and origin of important traits associated with the orb web, including both its construction and use, and how these traits can change over evolutionary time.

Nikolas J. Willmott "Flexible foraging and mating behaviours in an orb weaver," Arachnology 19(7), 976-981, (8 March 2024). https://doi.org/10.13156/arac.2024.19.7.976