Year: 2025
Type: article
Abstract: 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.
Source: Frontiers in Marine Science
Authors: Mingguang Mao, Yaru Wang, Jielan Jiang, Xiangcheng Tang, Xiaoming Geng
Institution: Hainan Tropical Ocean University
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Life below water
Open Access status: gold
Estimated APC paid: $3,801
Award: G1808919062
OpenAlex ID: W4415096807