Pacific Scarlet Cleaner Shrimp Lysmata amboinensis

The Pacific Cleaner Shrimp is also called the Scarlet Cleaner Shrimp, but the latter name is also used for two related species, Lysmata debelius and L. grabhami. It is also called the White-banded Cleaner Shrimp in the aquarium trade. It is native to caves and reef ledges in the tropical Indo-Pacific Oceans.

It grows to 6cm long excluding its long white antennae. It has offwhite flanks and underside with a scarlet back intersected by a bright white central line which stops with a "T" shape at the tail junction. The tail is red with a central white spot and four small white spots on the edges. (On its relative, the Caribbean Cleaner Shrimp, the central white line continues to the end of the tail and there are no white edge spots.)

As a cleaner shrimp, most of its diet is cleaning dead tissues and parasites from larger fish, which keeps the client fish healthy and also helps wounds to heal; in return, in addition to food, the shrimp receives protection from predators. Often a territorial, monogamous pair will share a cave or crevice with a client such as a moray eel and will defend their territory to the death from intruder cleaner shrimps. After months as a larva, the shrimp develops as a male and then as a hermaphrodite, after which a pair will take it in turns to take the male and the female (egg-carrying) role.