Population Genetic Structures of the Jellyfish Polyps along Korean Coasts and Implications as Revealed by Mitochondrial .

The moon jellyfish, , is is globally distributed, and its blooms have been responsible for severe environmental impacts. Benthic polyp populations are important for forming and maintaining medusa populations; however, their genetic structures are mostly unknown. Here, we analysed the genetic structure and phylogeographic pattern of polyps using the mitochondrial of 229 specimens collected from four different coastal regions of Korea. Molecular discrimination by assigned all polyps to . Population genetics revealed 53 haplotypes with high diversity and significant genetic structure, distinguishing two haplogroups (A and B) that coexist in all regions. Haplogroup A exhibited a star-like haplotype network pattern, while haplogroup B demonstrated a branched haplotype network pattern. Our results suggest that, the two haplogroups detected have existed in sympatry along Korean coasts. However, haplogroup A may have been established by a recent population expansion, while haplogroup B may have been established a long time ago. The strong genetic structure found within the polyp population of may have an effect on the moon jellyfish blooms on Korean coasts.