Morphological Analysis Reveals a Compartmentalized Duct in the Venom Apparatus of the Wasp Spider (Argiope bruennichi).

Henrike Schmidtberg,Andreas Vilcinskas,Tim Lüddecke,Björn M Von Reumont,Sarah Lemke

doi:10.3390/toxins13040270

Abstract

Spiders are one of the most successful groups of venomous animals, but surprisingly few species have been examined in sufficient detail to determine the structure of their venom systems. To learn more about the venom system of the family Araneidae (orb-weavers), we selected the wasp spider (Argiope bruennichi) and examined the general structure and morphology of the venom apparatus by light microscopy. This revealed morphological features broadly similar to those reported in the small number of other spiders subject to similar investigations. However, detailed evaluation of the venom duct revealed the presence of four structurally distinct compartments. We propose that these subunits facilitate the expression and secretion of venom components, as previously reported for similar substructures in pit vipers and cone snails.

Highlights

Venoms have convergently evolved more than 100 times in all major animal lineages, where they are employed as an important functional trait [1,2]
The wasp spider venom gland is a large organ that reaches deep into the prosoma. It is surrounded by attached muscles, a conformation observed in other spider venom glands
Research has focused on a small and unrepresentative selection of species, and little is known about the diverse nature of spider venom and even less about the morphology and architecture of the corresponding venom systems

Summary

Introduction

Venoms have convergently evolved more than 100 times in all major animal lineages, where they are employed as an important functional trait [1,2]. The three principal biological functions of venom are predation, defense and competition [3]. At least 11 additional functions have since been described, including venom usage for mating, food storage and even communication [1,3]. This functional diversity is inherently linked to the organization of the venom delivery apparatus. A detailed understanding of the morphological organization of venom delivery systems in animals is, necessary to understand their function and evolution

Methods

Discussion

Conclusion