The genus Alpioniscus Racovitza, 1908 in Sardinia: taxonomy and natural history (Isopoda, Oniscidea, Trichoniscidae)

The genus Alpioniscus Racovitza, 1908 (Trichoniscidae) from Sardinia is revised. Three new cave-dwelling species are described: A. onnisi Taiti & Argano, sp. n., A. stochi Taiti & Argano, sp. n., and A. sideralis Taiti & Argano, sp. n.. The genus Utopioniscus Schmalfuss, 2005 is considered to be a junior synonym of Alpioniscus, after morphological and molecular analyses. Alpioniscus fragilis (Budde-Lund, 1909) and A. kuehni from Grotta del Bue Marino are illustrated. With the new species, the genus Alpioniscus in Sardinia comprises six species: two troglobionts (A. fragilis and A. onnisi), one endogean and troglobiont (A. thanit Taiti & Argano, 2009), and three stygobionts (A. kuehni, A. stochi, and A. sideralis). All the species occur in karstic areas in the central-eastern and south-eastern part of the island. A key to all the Sardinian species of Alpioniscus is provided.