Theodoxus pallida Dunker, 1861

Gloeer, Peter & Pesic, Vladimir, 2012, The freshwater snails (Gastropoda) of Iran, with descriptions of two new genera and eight new species, ZooKeys 219, pp. 11-61 : 14-15

Theodoxus pallida Dunker, 1861 Figs 3a-b

Records from Iran.

Isfahan and Fars Province ( Starmühlner and Edlauer 1957).

Material examined.

NHMW 75000/E/50824, " Theodoxus pallidus Dunker" Persien, Brackiger Quellsee, 500 m, nördl. vom Niris-see, leg. Starmühlner 1949.

Remarks.

Starmühlner and Edlauer (1957) provide a detailed description of the anatomy of this species but did not consider the operculum, the most important diagnostic feature. On the other hand, as figured in Starmühlner and Edlauer (1957), the receptaculum seminis and the bursa copulatrix differ in length (while being of equal length in Theodoxus fluviatilis) .

The re-examination of the specimens of Theodoxus pallida (Dunker, 1862) from Edlauer’s collection in NHMW clearly shows that this species is distinct from Theodoxus fluviatilis due to the shape of shell and the operculum ( Fig. 3 ). As already mentioned by Dunker (1862) the spire in Theodoxus pallida is higher than in Theodoxus fluviatilis ,and furthermore the apophysis of the operculum is broader and not attenuated at its basis ( Fig. 3c ). In addition the callus at border of the operculum in Theodoxus pallida is much stronger ( Fig. 3c arrow).

Distribution.

Iran.

Figures

Figure 3. a-c Theodoxus pallida (from Edlauer's collection, NHMW 75000 / E / 50824) a Shell with corroded apex b label of Edlauer's collection c apophysis of Theodoxus pallida d apophysis of Theodoxus fuiviatilis (from IR 79).