New records of Pseudionine Bopyrid Isopods, including two new Species and one new Genus, infesting Porcellanid Crabs (Decapoda: Anomura) on the Pacific coast of North and Central America.

Abstract.--Aporobopyrus bourdonis, new species, earlier reported from the Pacific coast of Mexico but never described, infests Petrolisthes edwardsii (de Saussure), the same host species as before, in Costa Rica. Aporobopyrus muguensis Shiino, 1964, previously reported several times along the coast of California infesting Pachycheles rudis Stimpson and P. pubescens Holmes, is redescribed on the basis of material from Monterey, California, infesting P. pubescens. Aporobopyrus trilobatus (Nierstrasz and Brender a Brandis, 1925), previously known from the Caribbean Sea and the Pacific coast of Mexico, infests Petrolisthes ortmanni Nobili, a new host record, in Costa Rica. Discomorphus magnifoliatus, new genus, new species, infests Petrolisthes cinctipes (Randall) in central California. Synonymies are given for all species. Included is a summary of all porcellanids known to bear bopyrid parasites in the eastern Pacific.

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There are relatively few species of bopyrid isopods known from the Pacific coast of the Americas (Markham 1992). Ongoing collections and reexamination of material already in museum collections are slowly increasing the number of known species from that coast, though it will probably never become large. Material of two species, both new to the fauna of Costa Rica, had been collected as parasites of two crabs in the anomuran family Porcellanidae on the Pacific coast of Costa Rica and were housed in the collection of the Museo de Zoologia, Universidad de Costa Rica (designated UCR). One proved to belong to a species earlier recorded from elsewhere, while the second had previously been recorded but not described. Another specimen from California, in the collection of the National Museum of Natural History, Smithsonian Institution (designated USNM), for over 50 years, represents a new species in a new genus.

Systematies

Family Bopyridae, Rafinesque, 1815

Subfamily Pseudioninae R. Codreanu, 1967

Genus Aporobopyrus Nobili, 1906