Cleaner Shrimp (such as the Banded Coral Shrimp in the lower right hand corner) are the dentists of the ocean. Fish and marine animals go to locations (called Cleaning Stations) where cleaner shrimp and cleaner fish do their "cleaning" which may consist of eating of food caught in teeth, removing dead scales and barnacles from the body of the fish, etc. This rather large Moray Eel was sitting on the bottom next to the cleaner shrimp seemingly waiting for the dentist.