Marine Isopod Crustaceans from Easter Island1

Isopods from 29 shallow-water stations around Easter Island were identified. Thirteen species in three suborders are described as new: suborder Anthuridea, Mesanthura pascuaensis, Sauranthura rapanui, Califanthura dodecaseta, Paranthura nordenstami; suborder Asellota, Joeropsis acoloris, Joeropsis bicornis, Joeropsis limbatus, Joeropsis trilabes, Salvatiella islapascua, Uromunna biloba, Paramunna pellucida, Santia longisetae; suborder Flabellifera, Exosphaeroides quadricosta. Seven species were identified only to genus: Apanthura sp., Eisothistos sp., Carpias sp., Maresiella sp., Metacirolana sp., Munna sp., Panathura sp. The shallow-water marine isopods show an endemism of over 90%. A COLLECTION OF shallow-water marine isopod crustaceans made during two survey seasons on Easter Island in the South Pacific was offered to me for identification by Christopher Boyko of the American Museum of Natural History, New York. Because very few records of isopods exist for this most remote of locations, I accepted the offer with alacrity. The results of this study are presented here. Isopods are one of the crustacean groups from Easter Island that have received little attention. The few previous records of this group are as follows: Two unidentified species of Dynamenella were recorded by DiSalvo et al. (1988) from nonliving coral; Botosaneanu (1987) described the blind anthurid isopod Cyathura (Stygocyathura) rapanuia from volcanic sand at midtide level on the shore; Boyko and Williams (2001) described a new species, Pseudionella akuaku, a parasitic bopyrid from the gill chamber of the hermit crab Calcinus imperialis. MATERIALS AND METHODS The material covered in this report was collected during two field seasons in 1998 and 1 Manuscript accepted 15 September 2002. 2 Department of Systematic Biology, National Museum of Natural History, Smithsonian Institution, NHB163, P.O. Box 37012, Washington, D.C. 20013-7012. Pacific Science (2003), vol. 57, no. 3:287-317 © 2003 by University of Hawai'i Press All rights reserved 1999 as part of an invertebrate survey of Easter Island, funded by the U.S. National Park Service, Gateway National Recreation Area Division of Natural Resources, as part of a Science Museum of Long Island/Explorers Club 5-yr research expedition to explore the impacts of El Niiio events on Wodd Heritage Sites. Isopods were collected from 29 field stations, mostly in the intertidal region (see Figure 1 and Appendix). All the material is deposited in the American Museum of Natural History (AMNH), aside from a few duplicate paratypes deposited in the National Museum of Natural History, Smithsonian Institution (USNM). The measurements provided are in all cases total length in millimeters, measured middorsally from tip of cephalon to tip of pleotelson.