Polydora and Related Genera (Annelida, Polychaeta) from Eniwetok, Majuro, and Bikini Atolls, Marshall Islands

Abstract

In a study of more than 250 specimens of spionid polychaetes collected at Eniwetok, Majuro, and Bikini atolls, Marshall Islands (1956 and 1957) five new and two known species were found. One of the species (T. spinosa) is the type for a new genus, Tripolydora, which is closely related to Polydora, Pseudopolydora, and Boccardia by virtue of its modified fifth segment. It is unusual in having branchiae on the fifth segment, and the hooded hooks are trifid and begin on Segment 9. The other new species are Pseudopolydora corallicola, Pseadopolydora pigmentata, and Polydora tridenticulata from coral material, and Pseudopolydora reisbi from areas of pollution. The known forms, Pseudopolydora antennata Claparede and Polydora armata Langerhans, are considered in reference to the literature. The ecologic and systematic positions of the seven species are discussed