Ontogenetic and geographic venom variation in the Great Basin Rattlesnake, Crotalus oreganus lutosus

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  Ontogenetic and geographic venom variation in the Great Basin Rattlesnake, Crotalus oreganus lutosus Abstract Venom composition among the species of the Western Rattlesnake clade is often quite variable, depending on several factors such as geographic location and ontogeny. Venom composition not only affects the ability of a snake to acquire prey efficiently, but it can also significantly impact snakebite symptomology. Currently, there has been limited characterization of the venom from the Great Basin Rattlesnake ( Crotalus oreganus lutosus ), a lineage that is broadly distributed in the intermontane western United States. In this study we sample 67 individual Great Basin Rattlesnakes collected in Idaho, Utah, California, and Arizona. We find evidence for substantial ontogenetic and geographic variation in venom composition. Of the six toxin families assessed, all showed ontogenetic shifts to varying extents, with some trends differing from those observed in other rattlesnake sp...

A New Species of Trapdoor Spider (Araneae: Idiopidae: Heligmomerus) from the Southern Tip of India

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A New Species of Trapdoor Spider (Araneae: Idiopidae: Heligmomerus) from the Southern Tip of India

Abstract

A new species of the genus Heligmomerus is described based on 10 female specimens collected from
the foothills of Pothaimalai, on the outskirts of the Kalakad-Mundanthurai Tiger Reserve, Tirunelveli
District, Tamil Nadu, India. The new species is distinguished from all other Indian and Sri Lankan
congeners in combination with several non-overlapping morphological characters. Detailed natural
history of the new species, intraspecific variation in spermathecal morphology, and meristic and
mensural data from the type series are given. Additionally, comments on the transfer of Idiops
garoensis (Tikader, 1977) to the genus Heligmomerus by Sen et al. (2012) are provided.

Waghe, Vivek. (2025). A NEW SPECIES OF TRAPDOOR SPIDER (ARANEAE: IDIOPIDAE: Heligmomerus) FROM THE SOUTHERN TIP OF INDIA. 10.47605/tapro.v14i1.350.