Rediscovery and redescription of Entoniscus creplinii Giard and Bonnier, 1887 (Isopoda: Bopyroidea: Entoniscidae) parasitizing Polyonyx gibbesi Haig, 1956 (Decapoda: Anomura: Porcellanidae), a symbiotic crab from the tubes of Chaetopterus cf. variopedatus (Annelida), from North Carolina and Florida, U. S. A.

The porcellanid crab Polyonyx gibbesi Haig, 1956, an obligate symbiont of Chaetopterus cf. variopedatus (Renier, 1804) in the western Atlantic, is parasitized by a rare entoniscid isopod. Crabs from coastal North Carolina and Florida, U.S.A., were dissected and examined for this internal parasite in 1966 and 1967. Two of 83 crabs (2.4 %) and 3 of 100 (3.0 %) crabs from North Carolina and Florida, respectively, were parasitized. Only female parasites were found, including five immature and three mature specimens; one host was parasitized by three immature entonicisds simultaneously. One of the mature parasites was liberating epicaridium larvae and the others had developing eggs or larvae. Parasitized female crabs were all ovigerous; the parasites did not castrate the hosts. The parasite is identified as Entoniscus creplinii Giard and Bonnier, 1887, previously known only from Brazil, and the female is redescribed.