Recent moon jelly (Aurelia sp.1) blooms in Korean coastal waters suggest global expansion: examples inferred from mitochondrial COI and nuclear ITS-5.8S rDNA sequences

Abstract

The moon jelly Aurelio was found recently in Korean coastal environments, and its dense blooms caused economic losses for fisheries and power plants. The species is tentatively recognized as Aurelia aurita; yet, its identity and origin remain elusive. To find reliable molecular evidence for its identity, we determined the DNA sequence of the mitochondrial cytochrome c oxidase subunit I gene and nuclear ITS-5.8S rDNA of specimens collected from different Korean locations. We compared the nuclear and mitochondrial DNA data among specimens and demonstrated that all Korean Aurelio have an identical genotype. BLAST searches demonstrated that the Korean Aurelio matched the previously designated Aurelio sp.1. Parsimony and relevant phylogenetic analyses of the genus Aurelio demonstrated that the genotypes of Korean, Japanese, and Californian Aurelio sp.1 were nearly identical (>99.6% similarity), whereas they were significantly different (<84.1% similarity) from other Aurelio. This suggests that Aurelio sp.1, which occur in the three regions, are descendants of a single population and may have dispersed from one location. However, the dispersal time and origin of Aurelio sp.1 still remain uncertain.