Integrative Taxonomy of the Bubble Snails (Cephalaspidea, Heterobranchia) Inhabiting a Promising Study Area: The Coastal Sicilian Faro Lake (Southern Italy)

The worldwide diffused bubble snails, Haminoeidae, although characterized by an extreme morphological homogeneity, display the most diverse radiation inside the order Cephalaspidea. This hidden diversity within the family Haminoeidae was recently unraveled by molecular studies, which helped to understand the evolutionary history of this group by clarifying some aspects of its systematics. In fact, the type genus Haminoea W. Turton and Kingston (1830) was proved to be polyphyletic and, consequently, the genus Haminoea sensu stricto was restricted to the Mediterranean, Atlantic and East Pacific species, with the Mediterranean Haminoea hydatis Linnaeus (1758) as the type taxon. However, at the specie rank, many aspects need to be clarified, especially concerning the Mediterranean fauna. Due to low reliability of macro-morphological characters, the minimal quantity of molecular data currently available on Mediterranean specimen adds to the lack of molecular comparison in most reports. Based on such considerations, Haminoea species from an interesting Mediterranean study area, Faro Lake, a Sicilian coastal lake that is considered a hot spot for both alien and endemic marine Heterobranchia, have been studied using an integrative taxonomic approach. Eleven Mediterranean specimens belonging to four Haminoea bubble snails have been collected, identified and compared with samples from other localities, integrating ecological, morphological, anatomical (reproductive apparatus) and molecular data. Based on molecular investigations carried out on three different molecular markers (H3, 16S and COI), the morphological identifications of the species collected in the Faro Lake have been confirmed, and 37 new sequences are provided for future comparisons. Furthermore, results from this integrative systematic study shed light on the phylogenetic relationships occurring in this group of bubble snails that could be useful in identifying valid diagnostic morphological characters. Haminoea hydatis and H. navicula were confirmed to be close to each other, with H. orteai as sister to them and with H. orbignyana as the basal taxon. Given external morphological features are unreliable with species identification in Haminoea genus open questions on the geographical distribution of the species and on their ranges of intraspecific variability have yet to be addressed and further in-depth studies are needed. Finally, the presence of three sympatric Haminoea species, two of which are considered native or long-time naturalized, along with other occasional congeneric species, and the absence of the introduced invasive Haloa japonica, reflects both the resilience and stochastic space-temporal dynamics of Faro Lake. This confirms it as an inexhaustible source of case-studies

<p><strong><em>TANDONIA BOLENSIS</em></strong><strong> N. SP., A NEW SLUG (GASTROPODA: PULMONATA: MILACIDAE) FROM THE ISLAND OF BRAČ (DALMATIA, CROATIA)</strong><strong></strong></p>

The genus Tandonia Lessona & Pollonera, 1882 is represented along the Western Balkans by about 13 taxa, most of which are regional endemics. Recent collecting on the island of Brač (Croatia) has provided a single, fully grown specimen of a totally black slug. A careful investigation of the genital anatomy and body traits, reveal characteristic and unique morphological features which until now have never been observed in other representatives of the genus. Such results have led to the description of new species. Tandonia bolensis n. sp. is easily distinguishable by virtue of its genital features, the dummy-like penial-atrial papilla, and the long and partially spiral-convoluted, thorny spermatophore

Diversity and taxonomy of the genus Unio Philipsson in Italy, with the designation of a neotype for Unio elongatulus C. Pfeiffer (Mollusca, Bivalvia, Unionidae)

Novel Unio spp. populations from Slovenia, the Italian peninsula, Sardinia and Sicily were genetically analysed in order to define the distribution and diversity of the genus Unio in Italy and neighbouring areas. The presence of two primarily allopatric autochtonous species, Unio elongatulus Pfeiffer, and Unio mancus Lamarck, is confirmed for the Italian peninsula, Corsica, Sardinia, and Sicily. Autochthonous populations of Unio elongatulus are present in the peri-Adriatic drainages of the Italian and Balkan peninsulas, south as far as the Ofanto River (Apulia, Italy) and Lake Skadar (Albania), while its presence in the Tyrrhenian rivers of Tuscany is likely due to anthropogenic introduction events. Conversely, Unio mancus turtonii Payraudeau, an endangered peri-Tyrrhenian taxon, was found with autochthonous populations in the Apennine-Tyrrhenian drainages of peninsular Italy, eastern Mediterranean France, Corsica, Sardinia and Sicily, while the actual autochthony of the single population found in the Ionian basin of the Italian peninsula (Bradano River, Basilicata) deserves further investigation. The Italian population of U. mancus requienii Michaud, reported from Lake Montepulciano is to be considered allochthonous. The binomen U. elongatulus, although widely used in the recent scientific literature, was, to date, assigned to a doubtful species, because its type locality includes a large area inhabited by different Unio taxa, which are not clearly distinguishable by their shell alone; furthermore, no type material is present in historical collections. To retain the recently-used name, a new restricted type locality is established, where only U. elongatulus lives, and a neotype is designated. The validity of the subspecies of Unio mancus is also discussed and confirmed. Finally, hypotheses on the origin of Italian mussels, and considerations on their conservation status are discussed