Zoological Studies

Vol. 61, 2022

(update: 2022.3.18)

A New Branchipolynoe (Aphroditiformia: Polynoidae) Scale Worm from the Onnuri Deep-sea Hydrothermal Vent Field, Northern Central Indian Ridge

Sang Lyeol Kim1,2, Hyeongwoo Choi3, Seong-il Eyun3, Dongsung Kim1,2, and Ok Hwan Yu1,2,*

1Marine Ecosystem and Biological Research Centre, Korea Institute of Ocean Science and Technology, Busan 49111, Korea. *Correspondence: E-mail: ohyu@kiost.ac.kr (Yu).
E-mail: boyis20c@kiost.ac.kr (SL Kim); creo9447@naver.com (Choi); eyun@cau.ac.kr (Eyun); dskim@kiost.ac.kr (D Kim)
2Korea Maritime University, Busan 49111, Korea
3Department of Life Science, Chung-Ang University, Seoul 06974, Korea

Received 12 November 2021 / Accepted 3 March 2022
Communicated by Benny K.K. Chan

Deep-sea hydrothermal vents are dynamic environments with exotic fauna, including bathymodiolin mussels and scale worm annelids that often live in close associations. In this study, we found a new species of Branchipolynoe (Aphroditiformia: Polynoidae) living in the recently discovered mussel Gigantidas vrijenhoeki in deep-sea hydrothermal vents and methane seeps at 2,014–2,023 m depth. Based on the morphology and full mitochondrial genome sequences of specimens of Branchipolynoe from the Onnuri vent field (OVF) on the northern Central Indian Ridge, we describe them as a new species, namely Branchipolynoe onnuriensis sp. nov. This species resembles B. longqiensis and B. tjiasmantoi, but can be distinguished from these species by the shape of the notopodial acicular lobe and the tips of the subacicular neurochaetae. This identity is well-supported by genetic distance and phylogenetic analyses based on the mitochondrial c oxidase subunit I (COI) gene, with the new species being closest to the Western Pacific species B. tjiasmantoi. Phylogenetic analyses support close relationships between the Indian Ocean and Western Pacific hydrothermal polychaetes. Our data provide a foundation for exploring the evolutionary relationship between scale worms and bathymodiolin mussels.

Key words: Chemosynthetic environment, Full mitochondrial genome, Hydrothermal vent, Mitochondrial cytochrome c oxidase subunit I (COI), Polychaeta, Taxonomy.

Citation: Vecchi M, Stec D, Tommi V, Ryndov S, Chartrain J, Calhim S. 2022. Macrobiotus naginae sp. nov., a new xerophilous tardigrade species from Rokua sand dunes (Finland). Zool Stud 61:22.

Supplementary materials: Table S1丨Table S2丨Table S3丨Appendix 1丨Appendix 2丨Appendix 3丨Appendix 4丨Appendix 5丨Appendix 6