A contribution to the taxonomy of Spio (Spionidae, Polychaeta, Annelida) occurring in the North and Baltic Seas, with a key to species recorded in this area

摘要

In order to resolve taxonomic problems known from literature and diagnostic practices, Spio species currently recognised in the North Sea and the Baltic Sea have been re-examined. Spio species recorded in the area of interest are S. decoratus, Spio cf. filicornis, S. goniocephala, S. martinensis, and S. armata. Spio decoratus is restricted to the North Sea, whereas S. armata occurs only in the Baltic Sea. Revised descriptions with illustrations and notes on the distributions, as well as remarks on size-dependent differences of characters, are presented for all species. Specimens of Spio from the North and Baltic Seas, which are assigned to S. filicornis based on current taxonomic literature, exhibit significant morphological differences, and are here regarded as two different species. A definite assignment of specimens from the two morphological distinct groups to one of the known Spio species was impossible based on the material available. The significance of diagnostic characters used for the identification of Spio spp. is discussed. An identification key to Spio species found in the investigation area is provided.