Look at a coral reef and you will see all kinds of dangerous predators. Sharks have rows of razor sharp teeth. Moray eels hide in dark caves waiting to strike. But the loudest and most destructive creature in the entire ocean is actually the size of your thumb.
Meet the pistol shrimp. It does not have venom or massive jaws. Instead it carries a built in sonic weapon that defies the laws of physics. This little crustacean can snap its claw so fast that it literally boils the water around it. The resulting blast is one of the most violent and fascinating events in the natural world.
A Built In Stun Gun
The secret to this incredible superpower is a highly specialized and oversized claw. One half of the claw has a sharp plunger and the other half has a small socket. When the shrimp spots a tasty crab or a small fish, it cocks the plunger back like the hammer of a gun.
When it releases the tension, the plunger slams into the socket with terrifying speed. But the actual physical claw never touches the prey. The magic happens in the water itself. The movement is so incredibly fast that it rips the water apart and creates a tiny and temporary vacuum.
The Power of the Cavitation Bubble
This empty space in the water is called a cavitation bubble. As the surrounding ocean rushes back in to fill that empty void, the bubble collapses in on itself. This collapse happens in a fraction of a millisecond and generates a massive shock-wave.
The force of the implosion creates a loud popping sound that can actually deafen sonar equipment on military submarines. But the absolute craziest part is the heat. For a brief flashing moment, the temperature inside that tiny collapsing bubble reaches a staggering 8,000 degrees Fahrenheit. That is nearly as hot as the surface of the sun itself. It even produces a tiny spark of light that scientists call sonoluminescence.
The Ultimate Underwater Hunter
Any small fish unlucky enough to be swimming nearby is instantly knocked unconscious or killed by the shock-wave alone. The shrimp then simply strolls over and drags its stunned meal back into its burrow to eat in total peace.
These tiny creatures also use their popping claws to communicate with other pistol shrimp in the neighborhood. When whole colonies of them start snapping at the exact same time, it sounds like a massive frying pan full of sizzling bacon. It is a constant reminder that the ocean is full of bizarre and beautiful secrets. The next time you think of dangerous sea creatures, do not forget the little shrimp carrying a piece of the sun.
References: BBC Earth, National Geographic, Science Daily