
Partners
This observation refers to the Shrimp, known as Randall's Pistol Shrimp.
They have a symbiotic relationship with the Goby whom they shares a burrow/den.
The Shrimps are blind and they do the 'housekeeping' work, cleaning the burrow while the Goby sits at the entrance of the burrow watching out. They goby uses its tail to signal to the shrimp when it is 'safe' to excavate pebbles and stuff from inside the burrow and bring it out.

''Alpheus randalli'' is a species of snapping shrimp in the genus ''Alpheus''. It lives in the Marquesas Islands and parts of the Indian Ocean, including the Seychelles, in association with a goby of the genus ''Amblyeleotris''. The shrimp is transparent or white with prominent red markings.