Revision of five species referred to Myriochele and Galathowenia (Polychaeta: Oweniidae) from the Antarctic Seas based upon type material

摘要

Based on the examination of type material, five Antarctic oweniid species (Polychaeta: Oweniidae), belonging to the genus Myriochele and Galathowenia, were studied: Myriochele scotiae Hartman, 1978, Galathowenia wilsoni, Blake, 1984, Myriochele joinvillensis Hartmann-Schroder & Rosen-feldt, 1989, Myriochele longicollaris Hartmann-Schroder & Rosenfeldt, 1989 and Myriochele terranovensis Cantone & Di Pietro, 1998. The original description of M. scotiae has been emended due to the confirmation that the specimen described is a broken animal, and the shape of its anterior end is an artifact due to a breakage process. Galathowenia wilsoni and M. terranovensis are considered junior synonyms of Galathowenia scotiae (Hartman, 1978), new combination. Myriochele joinvillensis and M. longicollaris are regarded as valid species. Data are also given on the intraspecific variability of some body traits of high taxonomic relevancy in oweniids such as the shape of the head region, posterior end and anteroposterior variation of the hooked setae. The taxonomic status of the genus Galathowenia Kirkegard, 1959 is discussed, and a key to the species of the family Oweniidae recorded in Antarctic waters is provided.