A Review on the Microstructures and Taxonomy of the Acartia bifilosa (Crustacea: Copepoda) in Kyeonggi Bay, Yellow Sea

Acartia bifilosa has been classified as Rostratae group of Acartia by the characteristic of having the rostral filament. However, we have found that A. bifilosa does not have any rostrum. Therefore, A. bifilosa should be classified as Arostratae group. For the first time, we have observed that this species has only one genital pore in the genital segment. Two spermathecal canals are looped in lateral view as well as ventral view. We have also observed two thin, very short filaments and minute apertures on the anterio-ventral part of the top of the head. The function of the filaments need to be investigated.