Two New Lynx Spider Species of Hamadruas and Oxyopes and the First Record of Hamadruas Thorell, 1887 (Araneae: Oxyopidae) from Wai, Maharashtra, India

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  Two New Lynx Spider Species of Hamadruas and Oxyopes and the First Record of Hamadruas Thorell, 1887 (Araneae: Oxyopidae) from Wai, Maharashtra, India Abstract The present study reports two oxyopid spider species from Wai, Satara District, Maharashtra, India, based on morphological examination of specimens collected from the Kisan Veer Mahavidyalaya campus. The specimens were collected using hand-collection and sweep-net methods, preserved in 70% ethanol, and examined under a stereotrinocular microscope. Diagnostic structures, including the female epigyne and male palp, were studied after dissection, and distribution maps were prepared using QGIS. Hamadruas kvmensis sp. nov. is characterised by distinct dark elongated spermathecal lobes, a rounded central region forming the median fertilisation duct, curved copulatory ducts, and a male palp with an elongated curved cymbium, large bulb, prominent tegulum, slender embolus, conductor, tibial apophysis and sensory setae. Oxyopes wai...

Venom gland organogenesis in the common house spider

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Venom gland organogenesis in the common house spider

Abstract

Venom is a remarkable innovation found across the animal kingdom, yet the evolutionary origins of venom systems in various groups, including spiders, remain enigmatic. Here, we investigated the organogenesis of the venom apparatus in the common house spider, Parasteatoda tepidariorum. The venom apparatus consists of a pair of secretory glands, each connected to an opening at the fang tip by a duct that runs through the chelicerae. We performed bulk RNA-seq to identify venom gland-specific markers and assayed their expression using RNA in situ hybridisation experiments on whole-mount time-series. These revealed that the gland primordium emerges during embryonic stage 13 at the chelicera tip, progresses proximally by the end of embryonic development and extends into the prosoma post-eclosion. The initiation of expression of an important toxin component in late postembryos marks the activation of venom-secreting cells. Our selected markers also exhibited distinct expression patterns in adult venom glands: sage and the toxin marker were expressed in the secretory epithelium, forkhead and sum-1 in the surrounding muscle layer, while Distal-less was predominantly expressed at the gland extremities. Our study provides the first comprehensive analysis of venom gland morphogenesis in spiders, offering key insights into their evolution and development.

Venom gland organogenesis in the common house spider Afrah Hassan, Grace Blakeley, Alistair P. McGregor, Giulia Zancolli bioRxiv 2024.03.14.585096; doi: https://doi.org/10.1101/2024.03.14.585096