Type materials of the species of the Planorbidae (Mollusca, Gastropoda, Hygrophila) described by Shuichi Mori

ABSTRACT

The planorbid species that were described by Shuichi (Syuiti) Mori from Japan have long been enigmatic and their taxonomy has been highly confused. This situation is also an impediment to action for the conservation of Japanese planorbids which are one of the most threatened freshwater snail groups in the country. Based on our examination of Shuichi Mori’s collection stored in the Kyoto University Museum, type materials of the taxa described by him are re-illustrated and re-examined for the first time. Our examination suggested that Gyraulus amplificatus (Mori, 1938) is not a morphological form of Gyraulus biwaensis but a distinct species. Gyraulus pulcher (Mori, 1938) can be regarded as a junior synonym of Gyraulus chinensis.

和文摘要　JAPANESE ABSTRACT

森主一によって記載された Planorbidae Rafinesque, 1815 ヒラマキガイ科の種の実体は長い間謎に包まれており、その分類は大きな混乱が続いている。ヒラマキガイ科は日本で最も絶滅が危惧される陸水産の貝類の一群であるが、分類学的混乱はその保全施策の障碍となっている。そこで、著者らは京都大学博物館に収蔵されている森のコレクションの検討を行い、森によって記載された種のタイプ標本の図示と、形態的特徴の明確化を行った。結果として、Gyraulus amplificatus (Mori, 1938) ヒロクチヒラマキは G. biwaensis カドヒラマキの一形態型ではなく、明らかに区別されうる種であると示唆されること、ヒメヒラマキミズマイマイの学名とされてきた G. pulcher (Mori, 1938) は G. chinensis ヒラマキミズマイマイの新参異名である可能性が示唆されることが判明した。

KEYWORDS:

• Gyraulus
• taxonomy
• redescription
• freshwater snail
• Pulmonata
• Japan

Acknowledgements

Dr. Terufumi Ohno and Dr. Masaharu Motokawa are thanked for their assistance of our examination of the type specimens deposited in the Kyoto University Museum, Kyoto. Osamu Kagawa helped to take photographs of some specimens stored at Tohoku University. Finally, we are grateful to two anonymous reviewers and the Editor-in-Chief Dr. Don Colgan, who helped to improve the quality of this publication.

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

Takumi Saito http://orcid.org/0000-0003-1400-4523

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This study was funded in part by the Japan Society for the Promotion of Science Research Fellow Grant Number 16J04692 and 19J00392.