The Pistol Shrimp's Snap Reaches the Temperature of the Sun
A snapping claw, not a laser, briefly produces plasma hotter than the sun's surface.
When a pistol shrimp (genus Alpheus) snaps its specialized claw, the speed — roughly 25 meters per second — drops local water pressure so fast that a cavitation bubble forms. That bubble collapses almost instantly, and during the collapse the water inside reaches temperatures around 8,000 Kelvin. For a fraction of a microsecond, the temperature in a kitchen-sized crustacean's pincer rivals the surface of the sun.
The shockwave from the collapse can stun or kill small fish and invertebrates up to a few centimeters away. The shrimp never has to make contact.
In 2001, researchers at the University of Twente confirmed that the collapse also produces a faint flash of light — a phenomenon called sonoluminescence — though it's too brief and dim to see with the naked eye. The whole event, from snap to shockwave to flash, takes less than a millisecond.
Pistol shrimp are also among the loudest animals in the sea. Colonies of them produce a persistent crackling that registers on submarine sonar and can drown out other noise. During World War II, Allied submarines used the shrimp-dense waters near Australia to hide from Japanese hydrophone operators.
Make Recess yours.
Sign in to save the ones you loved, never see the same thing twice, and tell us what you want more of.