A research article published in the Journal of Experimental Biology has found that juvenile Alpheus heterochaelis have the fastest accelerating repeatable body part of any aquatic organism.
Reefkeepers know Pistol shrimp (Alpheus spp.) and their characteristic snapping sound only too well and introduce them deliberately as symbiotic partners for shrimp gobies or as stowaways in coral bases or live rock.
Adult Pistols stun prey with a spring-loaded claw, but we don’t see with the naked eye that the snapping mechanism squirts a high-speed jet of water, creating an imploding cavitation bubble and resultant shockwave, as well as a tiny flash of light at the same time.
So pistol shrimp are literally lightning fast, but Jacob Harrison at Georgia Institute of Technology found that the juveniles can snap their claws up to 20 times faster than the adults – making them even faster than Mantis shrimp, and as fast as a speeding bullet.
300 microseconds
Adult Snapping shrimp snap at 30,000 m/s2, but by using a camera, a microscope, and by filming at 300,000 frames per second, Harrison found that the juveniles were snapping at close to 600,000 meters per second squared. The whole snap took 300 microseconds while the blink of a human eye takes 500 times longer. “These are insanely high accelerations,” Harrison told the New Scientist, and he hopes his findings will help with the development of jumping robots and other spring mechanism objects.
Despite the finding, Pistol shrimp are still not the fastest movers in the animal kingdom. The Dracula Ant can shut its jaws in 23 microseconds (air is less dense than water,) while Jellyfish can release harpoons one hundred times faster than the snapping shrimp, although the movement is not repeatable. The shrimp have even evolved helmets to protect themselves from the damaging nature of their own shockwaves! Mother Nature never ceases to amaze.
