The tag‐along friendship: epibiotic protozoans and syllid polychaetes. Implications for the taxonomy of S yllidae ( A nnelida), and description of three new species of R habdostyla and C othurnia ( C iliophora, P eritrichia)

The presence of peritrich ciliate epibionts R habdostyla  sp. and C othurnia  sp. on S yllidae polychaetes is reported here for the first time, including the description of three new species of epibiont ciliates. The protozoans were mainly found at intersegmental furrows, close to parapodial bases of newly collected specimens of S yllis magdalena Wesenberg‐Lund, 1962, S yllis  sp., S alvatoria  sp., and Salvatoria concinna (Westheide, 1974)  comb. nov. from C hile, S yllis prolifera Krohn, 1852 from S pain, and P rosphaerosyllis magnoculata (Hartmann‐Schröder, 1986) from N ew Z ealand. In addition, epibiont protozoans were found on the dorsal surface, nuchal organs, mouth opening, and anterior cirri of S yllis elongata Day, 1949 from P eru, and the ventral surface of T yposyllis macropectinans Hartmann‐Schröder, 1982 from A ustralia. The discovery of protozoan epibionts on syllid polychaetes has important taxonomic implications that are discussed here. The presence of papillae that are in fact misinterpreted ciliate epibionts has been considered a valid character to distinguish among species or to erect new species of S yllidae, and thus the real origin of papillae‐like structures in polychaetes should be carefully assessed. © 2014 The Linnean Society of London