Cleaner shrimp is a common name for any swimming decapod crustacean that cleans other organisms of parasites. This is a widely cited example of cleaning symbiosis: a relationship in which both parties benefit. The fish benefit by having parasites removed from them, and the shrimp gain the nutritional value of the parasites. In many coral reefs, cleaner shrimp congregate at cleaning stations.
In this behaviour cleaner shrimps resemble cleaner fish, and sometimes actually may join them with cleaner wrasse and other cleaner fish attending to client fishes.
Cleaner shrimp may belong to any of three families, Palaemonidae (including the spotted cleaner shrimp, Periclimenes yucatanicus and Periclimenes magnificus), Hippolytidae (including the Pacific cleaner shrimp, Lysmata amboinensis) and Stenopodidae (including the banded coral shrimp, Stenopus hispidus) . The last of these families is more closely related to lobsters and crabs than it is to the remaining families. The term "cleaner shrimp" is sometimes used more specifically for the family Hippolytidae and the genus Lysmata.
Cleaner shrimp are often included in salt water aquaria.