Girardia tigrina (Girard, 1850)

Vila-Farré, Miquel, Sluys, Ronald, Almagro, Ío, Handberg-Thorsager, Mette & Romero, Rafael, 2011, Freshwater planarians (Platyhelminthes, Tricladida) from the Iberian Peninsula and Greece: diversity and notes on ecology, Zootaxa 2779, pp. 1-38 : 30-31

Girardia tigrina (Girard, 1850)

( Fig. 2 )

Comparative discussion. The freshwater triclad flatworm Girardia tigrina is one of the most widespread planarians in North America ( Kenk, 1944; Hyman, 1951; Mettrick et al. 1970; Chandler & Darlington, 1986; Thorp & Covich, 1991) and has successfully invaded several European countries ( Dahm, 1955; Gourbault, 1969; Van Der Velde, 1975; Ball & Reynoldson, 1981; Ribas et al. 1989; Gee & Young, 1993) as well as Japan, Australia and South America (Sluys et al. 1995). This eurythermic species ( Claussen & Walters, 1982) has been reported in many areas in the eastern sector of the Iberian Peninsula and the Balearic Islands ( Baguñà et al. 1980, 1981; Ribas et al. 1989) and on one occasion in Galicia in northeastern Spain ( Servia et al. 2006). It has also been reported in some isolated areas of central Spain ( Baguñà et al. 1981; Gamo & Gourbault, 1981).

Sampling at many localities of the Mediterranean area of the Iberian Peninsula have yielded specimens with external traits that correspond to one of the two known asexual strains of G. t i g r i n a (cf. Ribas et al. 1989): a markedly triangular head; two large and close-set eyes anterior to prominent auricular slits; a blotchy and grey dorsal surface; a pale ventral surface. However, the species is very scarce in Galicia and in the Cantabrian coastal region (records for the latter region are new; Fig. 2 ). All of the animals that were collected were asexual.

Figures

FIGURE 2. Distributional records of Girardia tigrina in the Iberian Peninsula. Data from Baguñà et al. 1980, 81; Ribas, 1990; Altaba et al. 1991; Servia et al. 2006; unpublished records, this study.