List of samples reported in the present study.

Sampling location data and museum registration numbers of newly collected material of Spiophanes spp.; museum samples examined during this study; material from the Norwegian, North, Mediterranean and Aegean seas and North Pacific reported by Meißner & Blank [111] and from the North Sea identified by Dieter Fiege, Markus Böggemann and Karin Meißner which is deposited in the SMF and other polychaete collections and was only partially re-examined by the first author (VIR); records of S. bombyx (= S. uschakowi) from Japan provided by Imajima [88, 116–118], for which no museum numbers were reported; records of S. bombyx (= S. cf. norrisi) from Chile, Argentina and the Falkland Islands provided by Carrasco [119] and Blake [48]; records of S. bombyx (here referred either to S. bombyx or S. cf. convexus) from Spain provided by Meißner [8]. (XLSX)