Alpioniscus kuehni (Schmalfuss, 2005) Schmalfuss, 2005

Taiti, Stefano, Argano, Roberto, Marcia, Paolo, Scarpa, Fabio, Sanna, Daria & Casu, Marco, 2018, The genus Alpioniscus Racovitza, 1908 in Sardinia: taxonomy and natural history (Isopoda, Oniscidea, Trichoniscidae), ZooKeys 801, pp. 229-263 : 229

Alpioniscus kuehni (Schmalfuss, 2005) comb. n. Figs 9, 10, 11, 18, 19

Utopioniscus kuehni ; Schmalfuss 2005: 2, figs 1-5, 7-35; Oertel and Patzner 2007: 62, 64, fig. 4; Taiti and Argano 2011: 166.

Material examined.

Prov. Nuoro: 4 ♂♂, 3 ♀♀ (MZUF 9827), Grotta del Bue Marino, c.n. 12 Sa/NU, 40°14'55.72"N, 9°37'24.80"E, Cala Gonone, Dorgali, 25.IV.2012, leg. E. Dallocchio and P. Marcia; 1 ♂, 1 juv. (MZUF 9828), same locality, 10.IX.2006, P. Marcia and F. Stoch; 11 ♂♂, 4 ♀♀ (MZUF 9829), Grotta Su Bentu, c.n. 105 Sa/NU, 40°15'18.23"N, 9°29'6.52"E, Lanaittu, Oliena, 6.I.2013, leg. P. Marcia; 2 ♂♂ (MZUF 9830), same locality, 11-14.IX.2012, leg. P. Marcia and Astronauts; 1 ♀ (MZUF 9831), same locality, 21.IX.2013, leg. Astronauts; 1 ♂, 2 ♀♀ (MZUF 9832), same locality, 15.IX.2014, leg. Astronauts.

Distribution.

The species is endemic to karstic areas of Supramonte, central-eastern Sardinia.

Remarks.

Alpioniscus kuehni was originally described as Utopioniscus kuehni gen. n., sp. n. by Schmalfuss (2005) on specimens collected in underground waters from two caves on the central-eastern coast of Sardinia, Grotta dell’Utopia and Grotta del Bel Torrente, with entrances at 30 m and 16 m below sea level, respectively. These caves are the estuaries of subterranean streams which open up in the sea ( De Waele and Forti 2003). In the Grotta del Bel Torrente the specimens were collected 700 m inland, where water salinity was 1% ( Schmalfuss 2005; Oertel and Patzner 2007). In the Grotta dell’Utopia they were collected 2000 m inland together with a species of the freshwater stygobiotic Stenasellus Dollfus, 1897 ( Asellota, Stenasellidae ). The specimens from Grotta del Bue Marino and Grotta Su Bentu here examined were collected in fresh water lakes and are morphologically identical to the specimens from the type localities. This fact confirms that A. kuehni is a freshwater stygobiotic species.

The species is well described by Schmalfuss (2005) and is here fully illustrated on specimens from Grotta del Bue Marino (Figs 9-11). As confirmed by molecular data (see below), the genus Utopioniscus must be considered to be a junior synonym of Alpioniscus . In fact, all the diagnostic morphological characters of the genus Alpioniscus mentioned by Vandel (1960) are present also in A. kuehni , in particular the shape of the male pleopods 1 and 2, as already pointed out by Schmalfuss (2005). Alpioniscus kuehni is mainly characterized by the enlarged shape of the pereon, the reduction of the number of aesthetascs of the antennula, the very thin antenna with the flagellum of 20 to 30 articles, the enlargement of the maxillipedal endite, and the lack of groove with scales on the pereopod 7 for the water conducting system. The last two characters are certainly adaptive for aquatic life. The enlarged maxillipedal endite is, in fact, present also in the following two new species which are both aquatic.