Cleaner Shrimp

Cleaner Shrimp

The term cleaner shrimp refers to a diverse assemblage of swimming decapod crustaceans spanning several marine families, notably Hippolytidae, Palaemonidae, and Stenopodidae. Found across tropical oceans, these small invertebrates play a vital ecological role on coral reefs by establishing mutualistic cleaning stations where they service client fish species. Among the most recognisable species is the Pacific cleaner shrimp (Lysmata amboinensis), which reaches a body length of 5 to 6 centimetres. It features a pale amber body marked by a central longitudinal white band bordered by broad scarlet stripes, accompanied by long white antennae. Another prominent representative is the banded coral shrimp (Stenopus hispidus), growing up to 90 millimetres in length. This species exhibits striking red-and-white bands across its spiny carapace, abdomen, and large pincers, set against white antennae and walking legs. Despite their brilliant colouration, studies indicate that species like L. amboinensis have coarse, colour-blind vision via their stalked eyes. Reproductive adaptations within the group are equally unique. Lysmata shrimp undergo protandric simultaneous hermaphroditism, maturing initially as males before becoming functional hermaphrodites capable of alternating sexual roles during mating. Conversely, Stenopus hispidus forms monogamous pairs that defend small territories measuring 1 to 2 metres across and utilize chemical signalling for individual recognition. Cleaner shrimp are beloved by underwater photographers and recreational divers for their remarkable interactive behaviours. At designated reef stations, shrimp congregate individually, in pairs, or in aggregations of up to 25 individuals. When host fish approach, the shrimp perform a rhythmic side-to-side rocking dance while waving their antennae to advertise their services. Their cleaning activities promote overall reef health by removing parasites, dead tissue, and wound mucus from host organisms.