A PHYLOGENETIC AND BIOGEOGRAPHIC STUDY OF EUNIPHYSA (EUNICIDAE, POLYCHAETA)
Lu, H.1,2 & Fauchald, K.2
1Department of Biological Sciences, the George Washington University, Washington, DC 20052, USA
2Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington D.C. 20560, USA
Fifteen species have either been described in, or referred to the genus Euniphysa. Seven species are here re-described based on type material; two new species, E. sp. n. 1 and E. sp. n. 2 are described. Euniphysa oculata is found to be a subjective synonym of E. spinea, and E. unicusa is a subjective synonym of E. aculeata; Euniphysa taiwanensis and E. megalodus are correctly assigned to genus, but cannot be described due to lack of material. Four other species are transferred to Eunice. A key is given to the nine identifiable species retained in Euniphysa. Coding strategies for polymorphic and inapplicable characters as well as problems associated with shared absences are discussed. A phylogenetic analysis of Euniphysa based on 24 morphological characters yielded a single most parsimonious tree (CI = 0.902, RI = 0.905). The tree topology separates Euniphysa into two distinct groups. Group II is supported by five unequivocal synapomorphies and two equivocal similarities, it includes E. aculeata, E. tridontesa, E. auriculata and E. falciseta. Group I includes the other five species; it is supported by five equivocal similarities. Based on the phylogenetic topology, Paraeuniphysa and Heterophysa are considered as junior synonyms of Euniphysa. The recognition of a separate family for Euniphysa is not warranted. All species of Euniphysa are fragile, shallow, warm water species. They have been collected mainly from sandy sediments of the Northern Hemisphere. The greatest diversity is from the South China Sea area; other species are found throughout the Indian Ocean, the Mediterranean Sea and the East Atlantic Ocean coasts suggesting a Tethys Sea origin. A few species have also been found in the Gulf of Mexico and the West Atlantic Ocean coast again suggesting a Tethys Sea origin associated with the westward drift of the North American continent.