Recent, phylogensis analyses that the rDNA sequence based on the LSU rDNA D1/D3, D8/D10 and ITS-5.8S rDNA regions showed that O. cf. ovata isolated from temperate water of Korea was different from that of all O. ovata and O. cf. ovata strains isolated from the other locations, but similar to that of Japanese strains of Ostreopsis sp. in the LSU rDNA D8/D10 and ITS-5.8S rDNA trees (Kang et al., 2013).