A recent study examined some of the world’s most deadly scorpions, suggesting that the death stalker, one of the most venemous scorpions in the world (with one of the coolest names), also has one of the fastest stings of any arachnid. As the Agence France-Presse reports, researchers recorded the tail strikes of seven scorpion species using high-speed cameras for the first time, finding that the death stalker, Leiurus quinquestriatus, snaps its stinger over its head at 51 inches per second—not too shabby for a creature just three to four inches long.
There are about 2,500 species of scorpions on earth, and the size and shape of their tails vary widely. The researchers wanted to figure out if the differences affected the ways in which the scorpions wield their tails—which are actually an elongated extension of their bodies called a metasoma—during defensive strikes.
The researchers recorded 23 scorpions from seven species in action at 500 frames per second. They placed the creatures in a small arena surrounded with mirrors, teasing them with a piece of wire to invoke a defensive strike. The researchers then converted the slow-mo video of the strike into a 3D computer model to analyze the trajectory of the venomous stinger at the tip of the tail.
The strike performance and techniques used by the seven species tested turned out to be very different. “We found that different ‘tail’ shapes appear to permit different strike performances,” Arie van der Meijden a biologist at the University of Porto in Portugal and senior author of the paper, tells the AFP.
The analysis showed that the death stalker as well as the emperor scorpion, the world’s largest (but not longest) scorpion, attack by moving straight toward their target and directly thrusting with their tail, a movement called an open pattern. Other species studied, including the black spitting scorpion (which douses its prey with venom at a distance), and scorpions in the genus Hottentotta, swing their tail in a slower O-shaped pattern when striking. They then return to roughly the same point where they began, something the researchers call a closed pattern.
According to the paper, the shape of the strike is likely related to each species defensive strategy. While an open pattern strike has a higher probability of directly hitting a predator, the closed strike brings the stinger back into the original position, ready for another hit. This, the researchers write, could be due to the types of predators nearby during the evolution of each of the scorpion species.
Van der Meiden tells the AFP that the stinger pattern could also be related to how each species uses its pincers to ward off predators. The researchers write that they hope to expand their study to determine the ecological and physiological reasons behind the different defensive strategies.