Description of Owenia gomsoni n. sp (Oweniidae, Annelida Polychaeta) from the Yellow Sea and evidence that Owenia fusiformis is not a cosmopolitan species

Two Owenia fusiformis populations from different geographical locations wer e compared to assess whether this species has a truly cosmopolitan distribu tion. The specimens were collected in Gomso Bay (South Korean coast, Yellow Sea) and Banyuls Bay (south French coast, Mediterranean Sea). The comparis on leads to the erection of the new species Owenia gomsoni, whose principal characteristics are: the presence of specific colour patterns on the branc hial stems and body sides in living animals; a branchial plume mounted on a base with five pairs of lobes; a marked, laterally incised, collar-like fo ld at the boundary between branchial plume and thorax; teeth of the bidenta te hooks vertically offset; very elongated setae scales and a marked prefer ence for quartz grains during tube construction. The present observations o n the new Yellow Sea species, complemented by others referred to in the pap er, lead to a reduction in the distribution area of Owenia fusiformis Delle Chiaje. It is concluded that, in fact, the species is a complex. In conseq uence, it cannot be considered cosmopolitan.