1. A further study in 2000 concluded that Actinia priapus; Tilesius, 1809, Actinia farcimen; Brandt, 1835, and Isometridium rickettsi; Carlgren, 1949 were all synonyms of Metridium giganteum.

Une autre étude en 2000 a conclu que Actinia pripaus (Tilesius 1809), Actinia farcimen (Brandt, 1835) et Isometridium rickettsi (Carlgren, 1949) sont tous des synonymes de Metridium giganteum.