ORIGINAL RESEARCH article
Front. Mar. Sci.
Sec. Marine Evolutionary Biology, Biogeography and Species Diversity
Volume 12 - 2025 | doi: 10.3389/fmars.2025.1650005
Complete Mitochondrial Genome of Polybranchia orientalis sp. nov. from the South China Sea
Provisionally accepted
- Yazhou Bay Innovation Institute of Hainan Tropical Ocean University, Sanya, China
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
A species of sea slug discovered in the South China Sea was characterized based on its morphology, mitochondrial genome, and phylogenetic position. The slug exhibits brown coloration, resembling seaweed. It features detachable, feather-like cerata capable of independent movement. The mitochondrial genome (14,452 bp; GenBank accession: PV637185) contains 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs, and a non-coding control region. Nucleotide composition showed a strong AT bias (65.55%), with AT-skew and GC-skew values of -0.1421 and 0.0607, respectively. Phylogenetic based on the cytochrome c oxidase subunit I (cox1) gene sequence analysis revealed a close relationship with Polybranchia orientalis, while BLAST analysis demonstrated high similarity between the cox1 gene of this sea slug and that of P. orientalis. Since the complete genome sequence of P. orientalis is currently unavailable, an additional phylogenetic analysis was performed using the 13 protein-coding genes (PCGs) of other sea slugs, which showed that this species clustered within a clade comprising several other species of the family Plakobranchidae. Integrating cox1 sequence data and morphological evidence, we assign this slug to the species Polybranchia orientalis sp. nov.. Interestingly, the cerata exhibit green pigmentation, and algal chloroplast genes were detected within them, suggesting kleptoplasty.
Keywords: Polybranchia orientalis sp. nov., Mitochondrial Genome, kleptoplasty, sacoglossa, South China Sea
Received: 21 Jun 2025; Accepted: 29 Sep 2025.
Copyright: © 2025 Mao, Wang, Jiang, Tang and Geng. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Jie-Lan Jiang, jielan06@foxmail.com
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.