[Matt Harty]

Wow, I never read this forum before but I realized the type of crab right after reading it. Saw it on some national geographic special and the crab is pretty badass. It was a clip of how the crabs claw worked in order to create cavitation bullets. The crab used it to stun a small shrimp and it was pretty awesome to watch. ;P

Pistol Crabs.

With the help of a special muscle alignment and a sort of spray-gun current they can accelerate a jet of water short-distance at up to 90 km/h. When they shoot, the tensed "pincer-valve" snaps together in less than one thousandth of a second and through the acceleration the water particles in the immediate vicinity heat up to more than 4000 degrees (!). The ultra hot cavitation-steam-bubble that results then implodes with a flash of light and a bang that at 240 decibels even dwarfs the roar of a jet fighter (ca. 150 decibels).