Characterization and comparison of the mitochondrial genomes of the sea star Asterias amurensis (Echinodermata: Asteroidea) in East Asia

Abstract

The starfish Asterias amurensis is a marine pest native to the northwestern Pacific and has successfully invaded southern Australia. Asterias amurensis have caused substantial environmental and economic impacts in both native and non-native regions. However, little information is available about the genetic features of its native populations, especially for those in North China. Here we sequenced the complete mitochondrial genomes of five individuals from different locations in China and compared their characteristics with three mitogenomes available from Japan. Multiple analyses and comparisons revealed little difference in the gene composition, gene order, codon usage, and nucleotide content among the eight mitogenomes. However, intraspecific phylogenetic reconstruction unveiled two divergent lineages between specimens from North China plus Ushimado (Seto Inland Sea, Japan) and northern Japan (Asamushi and Onagawa). This conclusion was backed by an analysis of pairwise genetic distances, which showed that individuals from different lineages had relatively higher values (all above 2%). Based on knowledge of paleoenvironmental and tectonic activity in the northwestern Pacific, the two lineages might have originated during the Early Pliocene due to the isolation of the East China Sea from the Japan Sea/East Sea during that time, while the present-day distribution of these lineages have likely been influenced by the ocean current system.

Keywords:

• Northern Pacific starfish
• mitochondrial genome
• intraspecific divergence
• marine refugium
• ocean current

Acknowledgements

We thank Shao’e Sun, Lu Qi, and Zhehao Li for their generous help in data analysis.

Disclosure statement

The authors declare that they have no conflicts of interest.

Additional information

Funding

This study was supported by the grants from the Young Talent Program of Ocean University of China [No. 862201013143] and the National Key Research and Development Program, China [2022YFC3106301] to Gang Ni and the National Programme on Global Change and Air-Sea Interaction [No. GASI-02-SCS-YDsum] to Xiaoqi Zeng.