Some Aegean and Anatolian Hydrobiidae W. Stimpson, 1865: One More Case of Phylogenetically Misleading Morphology

The availability of freshly collected Pseudorientalia natonica (Küster, 1853) enabled a revision of the putative Pseudorientalia Radoman, 1983, species from the Aegean islands of Chios, Samos and Lesvos. It is worth noting that there is no single sequence of ‘real’ Pseudorientalia in GenBank. Phylogenetic relationships were studied using cytochrome c oxidase subunit I (COI) sequences, alongside morphological analyses of the shell, radula, female reproductive organs and penes. Molecular data revealed a well-supported Pseudorientalia clade that included populations from Chios and Samos. These populations were shown to represent two distinct species that are new to science. Unexpectedly, Tefennia tefennica Schütt and Yıldırım, 2003, was nested within this clade. As the observed morphological differences were slight and variable, Tefennia is regarded as a junior synonym of Pseudorientalia. In contrast, the putative Pseudorientalia populations from Lesvos formed a separate, well-supported lineage, being a sister to Grossuana Radoman, 1983, and Daphniola Radoman, 1973. Despite their close morphological resemblance to Pseudorientalia, these populations represent a new genus. A similar pattern was detected in ‘Pseudorientalia’ kanari D. A. Odabaşı, 2024, which also represents a distinct new genus, and an additional new species was recognised within this lineage. In Graecoanatolica Radoman, 1973, marked shell variation was found in a single, molecularly undifferentiated species.