Low genetic diversity and lack of genetic structure in the giant jellyfish Nemopilema nomurai in Chinese coastal waters

ABSTRACT

The giant jellyfish Nemopilema nomurai is a scyphozoan species well-known in East Asian Marginal Seas for its damage to fisheries. The genetic diversity and population structure of N. nomurai, collected from five geographic regions in Chinese coastal seas, were examined based on mitochondrial cytochrome c oxidase subunit I (COI) gene and nuclear internal transcribed spacer one (ITS1) sequences. A total of 26 and five unique haplotypes were recovered from the COI and ITS1 genes, respectively. The overall genetic diversity of N. nomurai calculated by the COI and ITS1 sequences was low (haplotype diversity 0.727% and 0.108%, nucleotide diversity 0.212% and 0.039%). The median-joining network analysis revealed a star-like haplotype network. The hierarchical Analysis of Molecular Variance (AMOVA) of COI haplotypes showed that N. nomurai populations form a single population, with a low F_ST (0.0149, p = 0.1036). The dispersal ability, together with the biological characteristics, could be important factors for the lack of a geographically structured pattern in N. nomurai in Chinese coastal waters.

RESPONSIBLE EDITOR:

• Gavin Gouws

KEYWORDS:

• Nemopilema nomurai
• mitochondrial DNA
• genetic differentiation
• genetic diversity
• Bohai Sea
• Yellow Sea
• jellyfish blooms

Acknowledgements

We greatly appreciate the comments from Dr Gavin Gouws and the two reviewers, whose efforts helped to improve our manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by grants from the National Natural Science Foundation of China (No. 41206086; No. 41576152), the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA05130703), and the Research Encouragement Foundation of Excellent Midlife-Youth Scientists of Shandong Province (No. BS2011HZ023).