Tropical reefs are home to some of the most beautiful, diverse ecosystems on the planet. Gorgeous coral reefs span out across the expansive ocean floor supporting flocks of fish that radiate every color of the rainbow. Sharks glide gently across reef scattering smaller fish as they pass. However, it is not only the sights of the coral reef that can be astounding. In almost all tropical areas in the world there can be a symphony of snaps heard as soon as one dunks their head in the water. This is because of the Tiger Pistol Shrimp, Alpheus bellulus, and some of its amazing properties.
The Tiger Pistol Shrimp is part of the family Alpheidae of shrimp. These shrimp, like many other shrimp, have a symbiotic relationship with gobies. In this relationship the shrimp digs a den, which serves as a shelter for both of the animals, while the goby acts as a look out. The minute the goby retracts into the den, the shrimp follows. This is because the shrimp is basically blind, and therefore almost always has an antenna physically touching the goby. This is not unique to Alpheus bellulus however. These shrimp have an incredibly large claw that serves as their hunting mechanism. The shrimp are able to snap the claw hard and fast enough to create a cavitation bubble. This bubble reaches speeds of up to 60 miles per hour, and as it collapses the bubble also reaches 5000 K. This bubble is so strong that it can instantly kill small fish at a range of 4 cm. Since they are only 3-5 cm long this is quite a feat for such a small creature. Furthermore the snapping of the claw is loud enough to produce 200 decibels. This rivals the sperm whale and beluga whale for the loudest animal in the sea. These tiny shrimp are amazingly unique and quite well adapted to hunting and killing their prey. There is also evidence that these animals use their clicks to communicate with each other. Next time you dunk your head in the ocean and hear all of the miniature aquatic shootouts going on think of the tiny, majestic Tiger Pistol Shrimp.
A. Anker, S. T. Ahyong, P. Y. Noel, and A. R. Palmer (2006). “Morphological phylogeny of alpheid shrimps: parallel preadaptation and the origin of a key morphological innovation, the snapping claw”. Evolution 60 (12): 2507–2528. doi:10.1554/05-486.1. PMID 17263113.