Genus Atrioplanaria De Beauchamp, 1932

During the late 1930s specimens of Atrioplanaria sp. were collected from a hydropetric habitat on limestone in the surroundings of Sassari (northwestern Sardinia), representing the first record of planarians from Sardinian subterranean water and the first Italian record of the genus (Benazzi, 1938a, 1942) (Fig. 3). A seasonal cycle with sexual and asexual reproduction was observed under laboratory conditions (Benazzi, 1942).

Dahm (1964) performed a karyological study on specimens of this population, revealing a chromosome number of 2n = 46. However, this author was unable to obtain a suitable idiogram due to the very slight and gradual differences between the very small chromosomes.

Unfortunately, several attempts during last decades to collect new planarians in the same water body were unsuccessful due to significant environmental changes, i.e. anthropogenic impact on suburban areas (G.A. Stocchino pers. obs.)

Other specimens of Atrioplanaria sp. were recorded in 1952 from Su Coloru Cave (northern Sardinia) and from an old mine (Baccu Arrosu, southwestern Sardinia) (Benazzi, 1982) (Fig. 3). These last findings were the first records of cave-dwelling populations of triclads in Sardinia.

Specimens of presumed Atrioplanaria sp. were also found in two small temporary rivers on Caprera Island in the La Maddalena Archipelago National Park (northeastern Sardinia) (Manconi et al., 1995; Pala & Casu, 1995) (Fig. 3).