"Gobi and Shrimp" by Steve Childs. Licensed under CC by-2.0 via Flickr.
This crustacean grows to approximately 1.2 inches long and has yellowish-green appendages and poor eyesight. It, like all members of the snapping or pistol shrimp family, has one small claw and one larger claw. The larger claw snaps closed quickly to create a wave of bubbles that generate a lot of acoustic pressure and noise. These bubbles can both be used as a communication tool and to stun prey for food.
The Randall's pistol shrimp has a symbiotic relationship, known as mutualism, with a fish called the Randall's prawn goby (Amblyeleotris randalli). Mutualism is where two species are dependent on each other and both benefit from the relationship.
These two species both live in expansive sandy burrows on the sea floor. The shrimp digs and maintains the burrow and is responsible for covering the burrow openings at night. The shrimp disrupts small invertebrates with its digging, which the goby feasts upon. The shrimp eats the detritus left after the goby is done. The goby, which has good eyesight, is responsible for protection. When the two leave the burrow, the goby will rest its tail fin against the shrimp's antennae. If it senses danger, it will flip its fin and the shrimp will retreat back to the safety of the burrow.
Male and female Randall's pistol shrimp do not share burrows, but will build passageways between adjoining burrows.
The Randall's pistol shrimp is often bred for aquarium living, where it will work symbiotically with many other types of goby, including the flagtail shrimp-goby seen in the photo above.
Learn more about shrimp with these Science NetLinks resources: Check out our two-part lesson on brine shrimp (sometimes marketed as Sea-Monkeys), listen to a podcast about why, to be a true champion, a prizefighter should really try to punch like a mantis shrimp, and find out how shrimp farms help contribute to the devastation of tsunamis.
Do symbiotic relationships interest you? You can learn about the relationship between goby and coral, between a mushroom and the conifers it lives beneath, and between humans and the bacteria that live on our skin. Most symbiotic relationships involve just two species, but not always; learn about one that involves three.