A new peltospirid snail (Gastropoda: Neomphalida) adds to the unique biodiversity of Longqi vent field, Southwest Indian Ridge

ABSTRACT

The biodiversity of deep-sea hydrothermal vents in the Indian Ocean remains poorly characterised compared with that of their Pacific and Atlantic counterparts. Although the Longqi hydrothermal vent field is the most extensively explored vent site on the ultra-slow-spreading Southwest Indian Ridge, it is still a source of new discoveries. Here, we report and formally describe a new peltospirid snail from Longqi – Lirapex felix sp. nov. Known from only two specimens, it differs from other named Lirapex species by a depressed spire and the lack of coil loosening on the body whorl. Examinations of the external anatomy and radular characteristics agree with its placement in Lirapex, which is also supported by a molecular phylogeny reconstructed using the barcoding fragment of the mitochondrial cytochrome c oxidase I (COI) gene. This is the fifth peltospirid snail known to inhabit the Longqi field, three of which (including Lirapex felix sp. nov.) have been found nowhere else. There is growing evidence that the Longqi field represents a biogeographically unique site among Indian Ocean vents. The discovery of Lirapex felix sp. nov. adds to the unique biodiversity of Longqi field, with implications for conservation in the light of potential deep-sea mining.

This work is registered in ZooBank under: urn:lsid:zoobank.org:pub:3B892762-2110-4A1E-A80D-1779CBEC5EB3

KEYWORDS:

• deep sea
• hydrothermal vent
• Indian Ocean
• Mollusca
• new species

Acknowledgements

We thank the Master and crew of RRS James Cook and R/V Xiangyanghong 9 for their tireless support of scientific activity onboard expeditions JC67 and DY35, respectively. We extend the same thanks to the pilots and technical teams of ROV Kiel6000 and HOV Jiaolong, staff of the United Kingdom National Marine Facilities at the National Oceanography Centre, for logistics and shipboard support, and all scientists onboard the expeditions. Yukiko Nagai (JAMSTEC) is thanked for her assistance with microscopy.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability

Newly generated molecular data are deposited in NCBI GenBank under the accession number MW452523. Specimens used are deposited at the Repository of the Second Institute of Oceanography (RSIO 35,733), Ministry of Natural Resources, Hangzhou, China, and the National Museum of Nature and Science, Tsukuba (NSMT-Mo 79160), Japan.

Additional information

Funding

RRS James Cook cruise JC67 was supported by a United Kingdom Natural Environmental Research Council (NERC) Small Research Grant to JTC [NE/H012087/1], and the R/V Xiangyanghong 9 cruise was supported by the Foundation of China Ocean Mineral Resources R & D Association [No. DYHC-125-35]. CC was supported by a Grant-in-Aid for Scientific Research (KAKENHI) from the Japan Society for the Promotion of Science (JSPS) [under grant code 18K06401]. This work was also supported by an additional grant from the Foundation of China Ocean Mineral Resources R & D Association [No. DY135-E2-1-02] and a Scientific Research Fund of the Second Institute of Oceanography, Ministry of Natural Resources, China [Grant No. QNYC1902].

Notes on contributors

Chong Chen

Chong Chen and Yadong Zhou conceived and designed the project. CC, JTC and YZ collected and preserved the studied specimens during their participation in the relevant research cruises. CC carried out morphological examinations of the specimens. YH and YZ carried out DNA sequencing; CC, YH and YZ analysed the molecular data produced. CC interpreted the data and drafted the manuscript, after which all authors contributed to the final version.