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 Sphaerodorum gracilis (Rathke, 1843) Sphaerodorum flavum Orsted , 1843 Notes Questionable status. Reported from Greece by Goumenaki (2005) . In the Mediterranean also known from Italy ( Castelli et al. 2008 ), Spain ( Serrano-Samaniego 2012 ) and the Adriatic ( Mikac 2015 ). Present in the adjacent Sea of Marmara ( Cinar et al. 2014 ). Otherwise distributed in the North Atlantic. While it is possible that the species occurs in Greece, it has so far only been reported in grey literature; its presence is therefore preliminarily considered questionable, pending confirmation.