Schmidtea mediterranea Benazzi, Baguñà, Ballester, Puccinelli & Del Papa, 1975

Stocchino, Giacinta Angela, 2018, 80 years of research on planarians (Platyhelminthes, Tricladida) from Sardinia, Italy: an annotated checklist, Zootaxa 4532 (4), pp. 539-552 : 543

Schmidtea mediterranea Benazzi, Baguñà, Ballester, Puccinelli & Del Papa, 1975

Schmidtea mediterranea is a species exclusively distributed in the western Mediterranean area, with both asexual (Catalan coast, Menorca and Mallorca) and sexual populations ( Corsica, Sardinia, Sicily, and Tunisia) (cf. Lazaro et al., 2011 and references therein). The asexual planarians bear a heteromorphic translocation affecting one member of the 1 st and 3 rd pair of chromosomes. Besides sexual and asexual diploid populations, two triploid populations are also known. A sexual eutriploid population has been reported from a single Sardinian locality, while an aneutriplod asexual population was found in Menorca, the latter bearing a translocation between the 1 st and 3 rd chromosomes (only one chromosome of each triplet) ( Benazzi et al., 1975; Casu et al., 1982; De Vries et al., 1984; Manconi et al., 1995; Pala & Casu, 1995; Baguñà et al., 1999; Lazaro et al., 2011).

Populations of S. mediterranea are mainly distributed in the northern part of Sardinia and inhabit permanent water courses ( Benazzi et al., 1975; Pala et al., 1980b; Casu et al., 1982; Vacca et al., 1993). However, three new populations were found inhabiting ephemeral waters. Planarians were found in two temporary ponds in the Giara di Gesturi (Pauli Perdosu) and in the Giara di Tuili high basaltic plateau localized in the central-southern Sardinia. A third population was found inhabiting a very small ephemeral stream near the Sa Ucca e’ su Peltusu Cave in northwestern Sardinia ( Fig. 2 ). Although no cocoons were found in the field, specimens mated and laid fertile cocoons under laboratory conditions (G.A. Stocchino pers. obs.).

Figures

FIGURE 2. Geographic distribution of species of the genus Schmidtea and Girardia recorded from Sardinia. 1, Rio Fiume Santo; 2, Rio Mannu di Portotorres; 3, Rio S. Miali; 4, Fiume Silis; 5, Rio Pedrasdefogu; 6, Rio Lu Bagnu; 7, Fiume Coghinas; 8, Rio S. Stefano, Caprera Island National Park; 9, Rio Cuga; 10, Rio Calvia; 11, Fiume Temo; 12, unnamed temporary rivulet near Su Peltusu Cave; 13, Rio Fraigada; 14, Fiume Tirso; 15, Rio di Siniscola; 16, Rio Berchida; 17, unnamed rivulet affluent of Rio Mannu di Milis; 18, temporary pond of Giara di Tuili; 19, Pauli Perdosu temporary pond of Giara di Gesturi; 20, Rio Mannu di Cagliari; 21, Rio Flumentepido. New records are indicated by asterisks.