3. Gobies and Pistol Shrimp: The Odd Couple of the Reef
On coral reefs, one of the most fascinating symbiotic interactions is that between some gobies and pistol shrimp. This unusual pair has created a great cooperative living arrangement that advantages both of them. Though poor in vision, the pistol shrimp—also known as snapping shrimp—is a superb burrower. It keeps working to build and preserve a burrow in the reef substrate, which provides a shared residence for the goby and the prawn. Conversely, the goby is a lookout for possible predators and boasts great vision. The two animals keep practically continuous physical contact; the prawn uses its antennae to keep touch with the tail of the goby. The goby signals the prawn to withdraw into the burrow by flicking its tail when it sees danger. Then both creatures rapidly vanish into their common refuge. While the goby finds a safe sanctuary it could not create on its own, this cooperation lets the pistol shrimp forage and build on its burrow under protection from predators it cannot see. Many species of gobies and pistol shrimp have developed to be totally dependent on one another as their relationship is so close. This amazing illustration of interspecies cooperation shows how even animals from different families may create intricate, mutually beneficial interactions in the varied and competitive setting of a coral reef.