SADLERIANA PANNONICA (FRAUENFELD, 1865): A LITHOGLYPHID, HYDROBIID OR AMNICOLID TAXON?

• Published in: Journal of molluscan studies 2004-02, Vol.70 (1), p.49-57
• Main Authors: SZAROWSKA, M., WILKE, T.
• Format: Article
• Language: English
• ISSN: 0260-1230; 1464-3766; 1464-3766
• DOI: 10.1093/mollus/70.1.49

The genus- and family-level position of the rare and endemic rissooidean species Sadleriana pannonica (Frauenfeld, 1865) is enigmatic. Depending on the anatomical characters used, it has been considered to belong to the genus Lithoglyphus (family Lithoglyphidae), to the genus Sadleriana (family Hydrobiidae) or to the genus Bythinella (family ‘Amnicolidae’). To establish the genus–family-level relationships of S. pannonica, comparative anatomical and histological studies with several rissooidean taxa were conducted. In addition, phylogenetic analyses based on two mitochondrial gene fragments, cytochrome c oxidase subunit I and large subunit rRNA, were performed. The anatomical studies revealed striking similarities between S. pannonica and Bythinella austriaca: from 10 characters considered, six are exclusively shared between S. pannonica and B. austriaca. This finding is supported by the genetic analysis where S. pannonica forms a highly supported clade together with four Bythinella species. Based on anatomical and molecular data, it can be concluded that Sadleriana pannonica is not a representative of the genus Sadleriana (Hydrobiidae), nor does it belong to the genus Lithoglyphus (family Lithoglyphidae). It very likely belongs to the genus Bythinella (‘Amnicolidae’). The correct name is therefore Bythinella pannonica (Frauenfeld, 1865). Given that a wrong family assignment of Bythinella pannonica could persist for such a long time, the present study is another example for the urgent need of detailed anatomical and molecular studies in the highly enigmatic superfamily Rissooidea.