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Until recently, the evolutionary origin of aquatic organisms in the Balearic archipelago (western Mediterranean) had been scarcely addressed. The freshwater gastropod genus Pseudamnicola Paulucci, 1878 (Hydrobiidae), consisting of ∼60 species in the Mediterranean area, is widely distributed across the major islands of Majorca and Minorca. From phylogenetic datasets of limited geographic coverage, a recent well-supported split has been inferred between the Minorca and Iberian Pseudamnicola species, but the phylogenetic position of the Majorca clade composed of three species remained uncertain. In this study, we extend published sequence data for the COI and 16S rRNA mitochondrial genes and the 28S rRNA nuclear gene in western Mediterranean populations of Pseudamnicola with homologous sequences from individuals of the non-surveyed region of Morocco to assess the origin of the Balearic species from a wider geographic perspective. Our maximum likelihood and Bayesian inference analyses recovered a strongly supported clade comprising the Majorcan species and four phylogenetic lineages in Morocco, two of which are new to science (described here as P. ramosae sp. nov. and P. ouarzazatensis sp. nov.). Dating the nodes using an external molecular clock rate, younger ages were estimated for the Majorcan species (∼1 Mya) than for the Moroccan ones (∼5 Mya), which were still younger than the formation of the Balearic Islands (∼30 Mya). An independent well-supported clade grouped the Minorca and Iberian species diverging at ∼4 Mya. Thus, we found two independent evolutionary origins within the Balearic archipelago likely attributable to long-distance dispersal events from the African and Eurasian continents. :pub:24D17C1D-4A42-4722-9867-D8D84465F55A :act:85EC4DF1-9BFA-4B28-B3F2-C091212AFCF1 :act:C790EAC6-F22B-489A-93EB-CABF9EEAF282 [ABSTRACT FROM AUTHOR]

The genus Pseudamnicola comprises a group of tiny springsnails inhabiting several continental and insular regions of the Mediterranean basin. Given the limited dispersal capabilities of these animals, it is difficult to explain the wide distribution range of the genus and, more specifically, its presence in isolated habitats, such as on islands. Thus, to investigate the process(es) that may explain these distribution patterns, we morphologically re-described and genetically analysed the six Pseudamnicola ( Pseudamnicola) species occurring in the Iberian Peninsula and the nearby Balearic Islands. Genetic relationships were explored by sequencing two mitochondrial ( cytochrome c oxidase subunit I and 16S rRNA) and one nuclear ( 28S rRNA) gene in 19 populations. Our morphological study confirmed the presence of previously described species, whereas our phylogenetic results revealed three lineages within the subgenus: one clade grouping the species from Minorca Island with an Iberian Peninsula species, a second clade grouping the three species from Majorca Island, and a third clade that consists of a single species, which occurs in both the Iberian Peninsula and Ibiza Island. Calculated speciation times show that the cladogenetic events involving the insular species seem to have occurred after the current conformation of the Balearic Islands ( c. 20 Mya). Therefore, the speciation process may have been related to subsequent transmarine colonizations, probably during the Messinian Salinity Crisis, and the Pleistocene glaciations when landmass corridors connected the islands with the continent. © 2014 The Linnean Society of London [ABSTRACT FROM AUTHOR]