Many examples abound. This partnership is hard to document. Usually there is a single fish – here there are two fish – paired with a very shy shrimp. The fish stand guard and the shrimp digs a small burrow. It is impossible to know how large but the space can accommodate all parties. They disappear in a flash if threatened. Most times all you see is a hole and the excavated sand and debris pushed to the side. I rarely rarely see the shrimp. He is smaller than the knuckle of your little finger and must be mighty tasty.