Ancylocaris; Actinimenes; Cristimenes; Periclimenes; Rapimenes; symbiotic shrimps

Based on recently published molecular phylogenies of Indo-West Pacific palaemonid shrimps and further morphological evidence, the systematic position of several species of the polyphyletic genus Periclimenes is revised. The generic name Ancylocaris Schenkel, 1902 is re-established for the anemone-associated P. brevicarpalis. Actinimenes gen. n., is proposed for the anemone-associated P. inornatus, P. ornatellus and P. ornatus, all of which have a subspatulate first pereiopod. Cristimenes gen. n., is designated for the echinoderm-associated species, P. commensalis, P. cristimanus, and P. zanzibaricus, all with a unique carpopropodal articulation of the second pereiopods. Rapimenes gen. n. is established for the hydroid and antipatharian-associated P. brucei, P. granulimanus, and P. laevimanus, for which the long, slender and unequal second pereiopods and prehensile ambulatory propodi are the main synapomorphic characters.