Venom-spraying scorpion the first of its kind in South America

By Earth Touch News
January 30 2025

Venom, and the means by which animals dish it out, is wildly diverse and infinitely fascinating. Some sting, others bite, a few have venomous spikes, and then there's that elite group of animal assassins that have learnt to squirt their venom from a distance, usually (if not always) to deter an attacker. The latest species now confirmed to be a member of the venom-spraying guild is a newly discovered species of scorpion from South America, called Tityus achilles (which is a suitably cool name). And it's the first of its kind from that continent known to exhibit such specialised behaviour.

Tityus achilles showing its defensive venom-spraying tactic in a lab setting. We recommend watching this fullscreen in high resolution. Video © Léo Laborieux



The species, described in a paper published late last year in the Zoological Journal of the Linnean Society hails from the Cundinamarca department of Colombia, in the mountainous Magdalena rainforest region. It joins just a handful of scorpion species from two genera found in Africa and North America that have been recorded spraying their venom.

Most of the planet's some 2,500 known scorpion species prefer to inject their venom when subduing prey or defending against predators. They do so using a specially adapted tail consisting of an aculeus (the upwardly curved pointy bit on the end of the tail) and a telson (the bulbous venom container to which the aculeus is attached). However, a select few have been documented squirting venom out of their aculeus, presumably as a defensive tactic similar to that seen in species like the Mozambique spitting cobra or the bombardier beetle.

"Most scorpions are likely capable of spraying venom. They just don't do it," author of the new paper Léo Laborieux told Live Science. "Venom-spraying is an inherently expensive strategy. There is likely a very intense selection pressure that would make it so that the behaviour is more advantageous than it is disadvantageous. There has to be something going on with the predators in the environment."


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Tityus achilles. Top: adult male. Bottom: subadult female. Image © Léo Laborieux

To test the ability of T. achilles to squirt its venom, Laborieux gently pinned down a sample of wild-caught specimens using a drinking straw and recorded their reactions on a high-speed camera. He tested 10 juvenile scorpions (adults are hard to come by) and documented 46 venom ejections, the most impressive of which reached a distance of 14 inches (36 centimetres). Most of the venom pulses were directed forwards, but some also shot backwards or even vertically.

For the Transvaal thick-tailed scorpion – a southern African species also known to eject venom from it's tail – toxin squirting appears to be a last resort that only comes into play when a predator actually snatches an arachnid by the tail. Laborieux's South American squirters, however, appear to spray their venom more readily and were also recorded performing "venom flicks" – short projections consisting of a single droplet typically flung from the tail.

More:
https://www.earthtouchnews.com/discoveries/new-species/venom-spraying-scorpion-the-first-of-its-kind-in-south-america/