Patterns of diversification of the operculate land snail genus Cyclophorus (Caenogastropoda: Cyclophoridae) on the Ryukyu Islands, Japan.

Autor: Hirano T; Centre of Northeast Asian Studies, Tohoku University, Sendai, Miyagi, Japan; Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan. Electronic address: hirano0223t@gmail.com., Saito T; Department of Biology, Faculty of Science, Toho University, Funabashi, Chiba, Japan., von Oheimb PV; Museum für Naturkunde - Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany., von Oheimb KCM; Museum für Naturkunde - Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany., Van Do T; Department of Aquatic Ecology and Water Environment, Institute of Ecology and Biological Resources, Vietnam Academy of Science and Technology, Ha Noi, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Ha Noi, Viet Nam., Yamazaki D; Centre of Northeast Asian Studies, Tohoku University, Sendai, Miyagi, Japan., Kameda Y; Center for Molecular Biodiversity Research, National Museum of Nature and Science, Tokyo, Tsukuba, Ibaraki, Japan., Chiba S; Centre of Northeast Asian Studies, Tohoku University, Sendai, Miyagi, Japan; Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi, Japan.
Jazyk: angličtina
Zdroj: Molecular phylogenetics and evolution [Mol Phylogenet Evol] 2022 Apr; Vol. 169, pp. 107407. Date of Electronic Publication: 2022 Jan 11.
DOI: 10.1016/j.ympev.2022.107407
Abstrakt: The Ryukyu Islands, an island chain in southwestern Japan, originated from land masses that separated from the Eurasian continent due to the formation of sea barriers about 1.55 million years ago. In this study, we investigated the phylogenetic relationships of the operculate land snail genus Cyclophorus (Caenogastropoda: Cyclophoridae) in the Ryukyu Archipelago and surrounding regions based on DNA sequence data. According to our results, all studied Cyclophorus specimens from Japan form a monophyletic group containing eight subclades. Six of these subclades were found only on the Ryukyu Islands. On most islands of the Ryukyu Archipelago, no more than one Cyclophorus subclade was recorded, which may be due to limited ecological niche space and competition. No subclade was found to occur on both sides of the Watase Line, a regional zoogeographical boundary. Divergence times were estimated based on a time-calibrated phylogeny. We found that multiple splits among the Japanese Cyclophorus subclades predate the emergence of major sea barriers in the Ryukyu Archipelago. Vicariance due to sea barrier formation, as assumed for many other taxa from the region, was thus likely not the main driver for subclade divergence in these snails. Instead, certain geographical features might have shaped the diversification of subclades prior to sea barrier formation. Given that Cyclophorus populations were also present on islands that have never been connected to other land masses, the snails must have colonized them via oversea dispersal. As not all nominal taxa corresponded to monophyletic groups, our molecular phylogenetic approach revealed that a taxonomic revision of the Japanese Cyclophorus fauna is necessary. The eight subclades may be regarded as potential species-level groups based on COI p-distances. A canonical discriminant analysis using shell morphological data revealed slight differences among the subclades.
(Copyright © 2022 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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