Mantis shrimps punch with the force of a bullet – and now we know how

The mantis shrimp packs a mean punch, smashing its victims' shells with the force of a .22 But that's not because it has particularly powerful muscles – instead of big biceps, it has arms that are naturally spring-loaded, allowing it to swing its fistlike clubs to speeds up to 23 metres per second. We know that the key part of a mantis shrimp's punch is a saddle-shaped structure on the arm just above the shrimp's club. This shape works a bit like a bow and arrow, says Ali Miserez at Nanyang Technological University in Singapore: the muscles pull on the saddle to bend it like an archer's bow, and when it is released that energy transfers into the club. Miserez and his colleagues used a series of tiny pokes and prods, as well as a computer model, to examine exactly how the shrimp's saddle holds all that energy without snapping.