Polychaetes of Greece: an updated and annotated checklist Faulwetter, Sarah Simboura, Nomiki Katsiaras, Nikolaos Chatzigeorgiou, Giorgos Arvanitidis, Christos Biodiversity Data Journal 2017 5 20997 20997 3N79Y 2017609 Rioja, 1941 Rioja 1941 Polychaeta Serpulidae Hydroides CoL Animalia Hydroides brachyacantha Sabellida 0 20997 Annelida species brachyacantha  Ecological interactions  Native status Non-native (casual)  Notes Species complex. Reported from Greece by Ulman et al. (2017). In the Mediterranean also known from Israel ( Ben-Eliahu 1991a), Turkey (  Cinar2006) and Spain ( Ulman et al. 2017). Probably originating from the Mexican Pacific ( Ulman et al. 2017), but the species has been shown to constitute a complex of cryptic and pseudo-cryptic species ( Bastida-Zavala and ten Hove 2003, Sun et al. 2016). The identity of Mediterranean specimens, their introduction status in the Mediterranean and the potential native range cannot be determined without molecular methods.