Amphipods in a Greek cave with sulphidic and non-sulphidic water: phylogenetically clustered and ecologically divergent

We characterized taxonomically, ecologically, and phylogenetically the amphipod community of Melissotrypa Cave (Central Greece), which comprises both freshwater and sulphidic lakes. We found four amphipod species: <i>Niphargus jovanovici</i>, <i>Niphargus lindbergi</i>, <i>Niphargus gammariformis</i> sp. nov. and an unknown species of <i>Bogidiella.</i> The three <i>Niphargus</i> species form a well-supported monophylum but differ in their ecology and morphology: <i>N. jovanovici</i> is a small and slender species inhabiting small freshwater voids, <i>N. lindbergi</i> is a large and stout species living in freshwater lakes, whereas <i>N. gammariformis</i> sp. nov. is a small and stout species found predominantly in a sulphidic lake. Available evidence suggests that diversification may have happened in a geographically restricted area and was driven by ecological differentiation. <i>Niphargus gammariformis</i> sp. nov. shows morphological convergences in diagnostic traits with two species hitherto classified into the genus <i>Pontoniphargus.</i> As molecular phylogenies show <i>Pontoniphargus</i> nested within <i>Niphargus</i>, we synonymize here <i>Pontoniphargus</i> with <i>Niphargus</i>. The species originally named <i>Pontoniphargus ruffoi</i> needed to be renamed into <i>Niphargus pontoruffoi.</i> http://www.zoobank.org/urn:lsid:zoobank.org:pub:4F5EED3B-DEB4-4402-BCE8-6AE2B65CCC3A