The underwater snap, crackle and pop sounds we commonly hear throughout the tropics are made by little shrimp bearing one enlarged front claw, which the shrimp can cock open.
Snapping shrimp have also been noted for their ability to reverse claws. When the snapping claw is lost, the missing limb will regenerate into a smaller claw and the original small claw will grow into a new snapping claw.
The shrimp grow from 1 to 2 inches long and snap for several reasons.
One is for food. In some species, the shock wave produced by the fast claw closure stuns plankton and passing fish. Other types of snapping shrimp crack small clams with their big claw.
Another reason shrimp snap is the same reason we humans sometimes "snap": It's a warning to others to back off. Snapping both defines and maintains a shrimp's territory.
When a snapping shrimp opens its claw it is one of the fastest movements recorded in the animal world. At 30,000 rpm it creates a water jet with a speed of 100 km/hr that creates a cavitation by causing water to vaporize and a vapor bubble to collapse. This generates a 200 dB bang that the shrimp can use to stun or even kill prey.
A short intense flash of light is emitted at bubble collapse. In light of the apparent similarity with sonoluminescence, this phenomenon is termed shrimpoluminescence.
The snapping shrimp competes with much larger animals, like the sperm whale and beluga whale, for the title of 'loudest animal in the sea'.
One species, called the petroglyph shrimp, makes branched channels up to 10 inches long on the surfaces of coral heads. These dark fissures resemble ancient Hawaiian petroglyphs and are easy to spot in places with large growths of encrusting corals. It is not known how these shrimp create furrows in coral, but some researchers believe it may be a chemical process.
An almost blind snapping shrimp species share burrows with shrimp goby fishes in a symbiotic relationship. The burrow is built and tended by the snapping shrimp, and the goby provides protection by watching out for danger. The goby, having the better vision, alerts the shrimp of danger twitching its tail, and then both retreat into the safety of the shared burrow.
West Side Specialty Dolphin and Snorkel Tours
Waianae Boat Harbor
Near Ko Olina and Disney Aulani, Oahu