14 September, 2021

All you need to know about scorpion weapons and their function


Scorpions are armed with two types of weapons: their pedipalps with powerful pincers and their stinger which can inject an effective venom. These weapons are essential for the scorpion's survival and have three main functions: Prey capture, defense and sexual behavior. 

Yuri Simone and Arie van der Meijden have recently published an very thorough and interesting review on all aspects of the scorpion weapons. Here you will find all you need to know about our current knowledge on the scorpion's use of their pincers, sting and venom, how they work and how the originated. This is probably the most complete overview I have ever read on this topic and I recommend the article very much! 

Scorpions possess two systems of weapons: the pincers (chelae) and the stinger (telson). These are placed on anatomically and developmentally well separated parts of the body, that is, the oral appendages and at the end of the body axis. The otherwise conserved body plan of scorpions varies most in the shape and relative dimensions of these two weapon systems, both across species and in some cases between the sexes. We review the literature on the ecological function of these two weapon systems in each of three contexts of usage: (i) predation, (ii) defense and (iii) sexual contests. In the latter context, we will also discuss their usage in mating. We first provide a comparative background for each of these contexts of usage by giving examples of other weapon systems from across the animal kingdom. Then, we discuss the pertinent aspects of the anatomy of the weapon systems, particularly those aspects relevant to their functioning in their ecological roles. The literature on the functioning and ecological role of both the chelae and the telson is discussed in detail, again organized by context of usage. Particular emphasis is given on the differences in morphology or usage between species or higher taxonomic groups, or between genders, as such cases are most insightful to understand the roles of each of the two distinct weapon systems of the scorpions and their evolutionary interactions. We aimed to synthesize the literature while minimizing conjecture, but also to point out gaps in the literature and potential future research opportunities.

Simone Y, Meijden Avd. Armed stem to stinger: a review of the ecological roles of scorpion weapons. J Venom Anim Toxins Incl Trop Dis. 2021;27. [Open Access]

Thanks to Yuri Simone for informing me about their article!

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