Anatomy, relationships and distribution of Taiwanassiminea affinis (Böttger) (Caenogastropoda: Assimineidae), with a reassessment of Cyclotropis Tapparone-Canefri

Abstract

Assiminea affinis (Mousson ms) Böttger, 1887(=A. queenslandica [Pilsbry ms] Thiele, 1927), a previously unrecognised Australian assimineid species, is described anatomically and allocated to the genus Taiwanassiminea Kuroda and Habe, 1950, first described from Taiwan. This is the first record of the genus from Australia. Taiwanassiminea affinis is found in slightly brackish waters in the upper tidal reaches of the larger rivers from northern Queensland to the Shoalhaven River in the southern half of New South Wales. The terrestrial Cyclotropis Tapparone-Canefri, 1883, which has somewhat similar shell and radular characters, is redefined and several species (Assiminea bedaliensis Rensch, 1934; Paludinella javana Thiele, 1927; Assiminea lentula, A. riparia and A. sororcula, all Benthem Jutting, 1963) previously included in Cyclotropis are transferred to Taiwanassiminea.

Keywords:

• Truncatelloidea
• Gastropoda
• taxonomy
• revision
• Taiwan
• Papua New Guinea
• Rugapedia
• Assiminea

Acknowledgements

We thank Michael Shea for rendering the illustrations and for field participation, Eunice Wong for field assistance, Alison Miller for producing the distribution map and Joshua Studdert for preparing the other figures. Joshua Studdert also did the shell measurements, provided assistance in the field and, with Yong Yi Zhen, undertook the SEM work. We also thank Dr R. Bieler and Dr M. Haase, as well as two unnamed reviewers for their helpful comments. The project was supported in part by an ABRS (Australian Biological Resource Study) grant to one of us (AH).