This odd couple consists of a goby and a shrimp. The shrimp, who has poor eyesight, dug their burrow and keeps it clean, while the goby is on the lookout for predators. It pushes the shrimp down the burrow when it detects danger. (Desert Seas - National Geographic Channel)
The goby signals ‘levels’ of danger by different flicks of it’s tail. The shrimp can detect the vibrations and stay in the burrow until the threat disappears, or the Goby retreats.
(via mad-as-a-marine-biologist)
