Polycelis nigra (Müller, 1774)

Habitat and localities in Tunisia from bibliography. Animals were usually found attached to plastic rollers and bottles in El Akarit River at approximately 100 m from the road Skhira-Gabes (Harrath et al. 2012a).

Other localities in the world. Austria (Salvenmoser et al. 2010); Switzerland (Fuhrmann 1894); USA (Muttkowski 1918); Belgium (Oye 1941); Italy Benazzi (1933); Scotland (Evan 1905). According to Ball & Reynoldson (1981), P. nigra is one of the most widespread species in Europe and it also occurs all over Britain