Description of a new species of Asymmetrione (Isopoda: Bopyridae: Pseudioninae) infesting the hermit crab Paguristes tomentosus (Anomura: Diogenidae) from Peru, with a key to species and a review of southeastern Pacific bopyrids

Abstract

A new species of bopyrid isopod is described from a host hermit crab Paguristes tomentosus collected from Pisco, Peru and assigned to the pseudionine isopod genus Asymmetrione Codreanu, Codreanu and Pike, 1965. This is the second species in the genus with less than 20° asymmetry in females, but agrees with all other species in the genus in having the characteristic “socket” on the propodus of the female's pereopods, and in all characters of the males. A key is provided to the 10 species now in Asymmetrione. New records of an Anathelges sp. from Pagurus villosus collected in central Chile are given but additional material is required to determine whether these specimens represent the eastern Pacific A. thompsoni or the western Atlantic A. hyptius. A review of all the bopyrid species known from the western South American coast, with remarks on their taxonomy and biology, is provided.

Keywords:

• parasitic isopod
• Chile
• South America
• zoogeography

Acknowledgements

FLM wishes to thank Marina Quiñe Fernandez (IMARPE) for donating the parasitized specimen of Paguristes tomentosus for a molecular study on systematics of hermit crabs. LPM wishes to thank David Ampuero Cobos for drawing and Guillermo Guzmán for providing bopyrid samples. We thank the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) during the International Cooperative Project – CNPq/Prosul Program (Grants 490340/2004-0 and 490122/2006-0), which provided financial support to FLM and LMP during the Brazil–Chile visiting programme. FLM is also indebted to CNPq for an ongoing research fellowship. We also thank the anonymous reviewers.