Swimming Crabs (Crustacea: Brachyura: Portunoidea) of Easter Island

The portunoid fauna of Easter Island is reviewed, based on historical records and material collected by the Science Museum of Long Island Easter Island Expedition of 1998–1999. Previously, only two portunoid taxa identified to the species level were recorded from the island. This work reports on six species of portunoids: Ovalipes elongatus Stephenson & Rees, 1968 (new record), Laleonectes nipponensis (Sakai, 1938) (new record), Portunus pubescens (Dana, 1852), Thalamita auauensis Rathbun, 1906 (new record), T. bevisi (Stebbing, 1921) (new record), and T. seurati Nobili, 1906 (new record). Specimens tentatively referred to Thalamita minuscula Nobili, 1906, are also discussed, but this taxon may represent the juvenile form of T. seurati. The new records from the island all represent large range extensions for each species. Color notes are provided for four species. The first pleopod of the male of O. elongatus is illustrated for the first time, and the species’ potential as an invasive taxon is discussed.