Polychaetes of Greece: an updated and annotated checklist Author Faulwetter, Sarah Author Simboura, Nomiki Author Katsiaras, Nikolaos Author Chatzigeorgiou, Giorgos Author Arvanitidis, Christos text Biodiversity Data Journal 2017 5 20997 20997 http://dx.doi.org/10.3897/BDJ.5.e20997 journal article http://dx.doi.org/10.3897/BDJ.5.e20997 1314-2828--20997 Hydroides dianthus (Verrill, 1873) Notes Species complex. Hydroides dianthus was originally described from Connecticut and long believed to be non-native in the Mediterranean ( Zibrowius 1973b , Zenetos et al. 2017 ). A recent study by Sun et al. (2017) shows, however, that Hydroides dianthus could originate from the Mediterranean, as the species shows the highest genetic diversity in the Mediterranean (nine out of ten haplotypes present, as opposed to only two haplotypes in the USA). The authors recovered also a putative cryptic species, Hydroides cf. dianthus , probably originating from the Gulf of Mexico and apparently recently introduced to the Black Sea.