High-throughput degraded DNA sequencing of subfossil shells of a critically endangered stenoendemic land snail in the Aegean.

High-throughput sequencing has enabled the comprehensive genetic exploration of biological diversity, especially by using natural history collections to study hard-to-find, threatened or even extinct-in-the-wild taxa. Mollusk shells are under-exploited as a source for DNA-based approaches, despite their apparent advantages in the field of conservation genetics. More particularly, degraded DNA techniques combined with high-throughput sequencing have never been used to gain insights about the DNA preservation in land snail subfossil or historical shells. Here, we applied degraded DNA analysis on two historical shells of Levantina rechingeri, a stenoendemic Critically Endangered species that has never been found alive, in order to explore the patterns of DNA preservation on land snail shells originating from the eastern Mediterranean, as well as to infer its molecular phylogenetic placement. Our results showed that centuries to decades-old DNA from an empty shell collected in an Aegean island exhibits characteristic post-mortem damage patterns similar to those observed in ancient DNA from eastern Mediterranean terrestrial animals, setting a precedent for future museomics studies on taxa distributed in areas with similar climate. Finally, genome skimming of the empty shell allowed high coverage of multiple nuclear and mitochondrial loci, enabling the phylogenetic placement of the focal taxon, the re-evaluation of its taxonomic classification, and the revealing of a new Aegean land snail lineage, Aristena genus novum. This approach is a non-invasive way to sample DNA from threatened land snail species and suitable to study the evolutionary history of taxa with cryptic ecology, stenoendemics, or extinct-in-the-wild, as well as old museum specimens.

The land snails (Mollusca, Gastropoda) of Kea island (Aegean, Greece).

Background: Kea is the westernmost island of the Cyclades and is located between Syros and Attica, in central Greece. In this work, we have resampled the island after 43 years - i.e. when the island was first fully sampled - and we present its complete land snail fauna. New information: We report 42 land snail species with 10 species being new records for the island. Based on our results we draw attention to the fact that sampling for land snails should be done during the wet period in order to survey the complete malacofauna in an island or a region. For such a complete survey, collection and inspection of soil and litter are also necessary. Finally, increased sampling effort through regular resurveys is a necessary prerequisite in order to effectively assess the temporal dynamics of biodiversity patterns.

A contribution to knowledge on the terrestrial malacofauna of the Kastellorizo (Megisti) island group (SE Greece).

BACKGROUND: The Kastellorizo island group (in the Dodecanese, Greece) is situated in the southeast corner of the Aegean Archipelago. It consists of twenty islets, of which the three largest (Kastellorizo, Ro and Strongyli) and seven smaller ones belong to Greece. Knowledge of the malacofauna on the islands is relatively poor. Only eight species were known prior to the present study, all from the islet of Kastellorizo. RESULTS: Here, using the scientific collections at the Natural History Museum of Crete collected mainly by the authors and also by several researchers since 1976, we reappraise the malacofauna of the island group. Thirty-one species were found in total (23 from Kastellorizo, 19 from Ro, 15 from Strongyli, 10 from Agios Georgios, 14 from Agrielia, 6 from Psomi and 10 from Psoradia). CONCLUSIONS: The fact that there are no endemic snail species in the islands can be accounted for by their proximity to the Turkish coast, their common paleogeography with Turkey until the Late Pleistocene and Holocene, and the influence of humans. All but two species, Mastus etuberculatus and Vitrea riedeliana, are known from the adjacent Turkish coasts. Together with the subfossil species found on the smaller islets, the predominance of different species on each islet suggests a continuous substitution from the source areas of Turkey and the Aegean.

Unraveling the evolutionary history of the Chilostoma Fitzinger, 1833 (Mollusca, Gastropoda, Pulmonata) lineages in Greece.

The land snails of the genus Chilostoma Fitzinger, 1833 that includes, in Greece, the (sub)genera Cattania, Josephinella and Thiessea, are highly diversified and present high levels of endemism. However, their evolutionary history is unknown and their taxonomy is complex and continuously revised. The aim of this study is to investigate the phylogenetic relationships of the lineages of the genus Chilostoma distributed in Greece based on partial DNA sequences of two mitochondrial DNA (16S rRNA and COI) genes. Complete sequences of one nuclear gene (ITS1) representing the major mitochondrial lineages were also analyzed. The phylogenetic trees revealed three distinct major clades that correspond to the three (sub)genera. Several taxonomical incongruencies were made obvious, thus, raising questions about the "true" number of species in each clade, while rendering a taxonomic re-evaluation necessary. From a phylogeographic point of view, it seems that the three major phylogenetic clades were separated in the late Miocene. They started differentiating into distinct species during the Pliocene and Pleistocene through several vicariance and dispersal events.

Terrestrial slugs (Gastropoda, Pulmonata) in the NATURA 2000 areas of Cyprus island.

Terrestrial slugs of the Island of Cyprus were recently studied in the framework of a study of the whole terrestrial malacofauna of the island. The present work was carried out in the Natura 2000 conservation areas of the island in 155 sampling sites over three years (2004-2007). Museum collections as well as literature references were included. In total six species are present in the Natura 2000 areas of the island, belonging to three families: Limacidae, Agriolimacidae and Milacidae. One of the species, Milax riedeli, is a new record for the island. The distribution of the species across the island and in the surrounding areas is discussed.