Tiger Pistol Shrimp

The pistol shrimp, belonging to the family Alpheidae (with prominent species like Alpheus bellulus and Alpheus randalli), is a small marine crustacean found in tropical and temperate coastal waters worldwide. Averaging 1 to 2 inches (2.5 to 5 centimeters) in size, these shrimp are instantly recognizable by their asymmetrical claws, where one claw is massively enlarged and specialized into a biological air-pistol mechanism. When the shrimp snaps this specialized claw shut at extreme speed, it shoots out a jet of water moving at over 60 miles per hour. This rapid movement creates a low-pressure cavitation bubble that collapses with immense force, producing a sharp shockwave, a brief flash of light, and a cracking sound reaching up to 218 decibels. The resulting blast wave is powerful enough to instantly stun or kill small prey like worms, small crabs, and fish, as well as defend the shrimp's territory against intruders.

In home reef aquariums, pistol shrimp are famous for their engineering habits and symbiotic relationships with watchman gobies. Because pistol shrimp have poor eyesight, the goby acts as an eagle-eyed sentinel at the entrance of their shared sand burrow, while the shrimp constantly digs and clears out tunnel networks. In exchange for the shrimp's construction work, the goby keeps guard, flicking its tail to alert the shrimp to retreat whenever danger approaches.