Periclimenes speciosus, a new species of anthozoan associated shrimp (Crustacea: Decapoda: Palaemonidae) from southern Japan.

A new species of palaemonid shrimp, Periclimenes speciosus sp. nov., is described and illustrated on the basis of 20 specimens collected from warm-temperate and subtropical waters of southern Japan. Periclimenes speciosus belongs to the "P. aesopius species group", and is associated with sea anemones and a scleractinian coral as well as behaving as a fish cleaner. Morphologically, the new species appears closest to P. holthuisi Bruce, 1969, but can be distinguished from P. holthuisi by the form and armature of the cutting edges of dactylus and fixed finger of the second pereiopod. The coloration in life of both species clearly discriminates one species from the other. The taxonomic status of some specimens previously reported as P. holthuisi is briefly discussed.