Zoological Studies

Vol. 62, 2023

(update: 2023.5.26)

A New Paralepetopsis Limpet from a South China Sea Seep Hints at a Paraphyletic Neolepetopsidae

Chong Chen1,*, Zhaoyan Zhong2, Jian-Wen Qiu3, and Jin Sun2

1X-STAR, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2–15 Natsushima, Yokosuka 237–0061, Japan. *Correspondence: E-mail: cchen@jamstec.go.jp (Chen)
2Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China. E-mail: zhongzhaoyan@stu.ouc.edu.cn (Zhong); qiujw@hkbu.edu.hk (Qiu)
3Department of Biology and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, 224 Waterloo Road, Hong Kong. E-mail: jin_sun@ouc.edu.cn (Sun)

(Received 20 June 2022 / Accepted 21 February 2023 / Published 26 May 2023)
Communicated by Benny K.K. Chan

Neolepetopsidae is a little-studied true limpet family only known from deep-sea chemosynthetic ecosystems, containing just over a dozen species in three genera: Neolepetopsis, Paralepetopsis, and Eulepetopsis. Although considered monophyletic by a recent phylogenetic analysis, a lack of Paralepetopsis sequence linked to morphology casts some uncertainty. Here, we discovered a new species of Paralepetopsis from the Haima methane seep in the South China Sea, described as Paralepetopsis polita sp. nov. The new species is distinct from all other described Paralepetopsis by its smooth and semi-transparent shell, combined with a radula exhibiting pluricuspid teeth with two cusps. We tested its relationship with other neolepetopsids using a molecular phylogeny reconstructed from the mitochondrial COI gene, revealing a surprising position nested within Lepetidae, a family with a very different radula morphology. The clade containing lepetids and our new species was recovered sister to other neolepetopsids with sequence data available. This hints at a paraphyletic Neolepetopsidae, and
suggests the neolepetopsid-type radula might not be exclusive to one monophyletic group of limpets.

Key words: Cold seep, Deep sea, Gastropoda, Mollusca, Phylogenetics.

Citation: Chen C, Zhong Z, Qiu JW, Sun J. 2023. A new Paralepetopsis limpet from a South China Sea seep hints at a paraphyletic Neolepetopsidae. Zool Stud 62:26. doi:10.6620/ZS.2023.62-26.