Adult specimens of Acartia bifilosa have been examined under SEM and evidence of the presence of rostral filaments in this species is confirmed. The suggestion of Shim & Choi (1996) to change its taxonomic position from the subgenus Acanthacartia to the subgenus Acartiura is therefore rejected. This report clearly shows that A. bifilosa should remain in its current taxonomic position, although further taxonomic/genetic studies on this species are necessary.