A cleaner shrimp does not wait to be noticed. It advertises.
Sitting at the mouth of a cave, it rocks its whole body side to side on the spot and waves a pair of long white antennae well out in front of itself. That display is a signal with a specific meaning, and reef fish read it correctly: a fish that wants service swims up, stops, and holds a pose - often head-down, mouth open, gill covers lifted - which tells the shrimp it may board.
What follows is a genuine transaction. The shrimp walks over the fish, picks parasites, dead skin and infected tissue out of the wounds, and works inside the mouth and gill chamber of animals that could swallow it without noticing. Fish queue for it. Predators that eat shrimp all day do not eat this one while it is working.
The display is also what makes them findable. Look into any cave with a torch and check the shadows for something small rocking rhythmically. If it is rocking, it is a cleaner.
- translucent body with red and white banding and long white antennae
- rocks its body back and forth on the spot
- in caves and under overhangs, often several together
- up to 6 cm
