L. Forró - É. Murai szerk.: Miscellanea Zoologica Hungarica 6. 1991 (Budapest, 1991)

Nesemann, H.: Zoogeography and composition of leech fauna of Danubian lowland rivers in the Kisalföld compared with some molluscs (Hirudinea, Gastropoda)

Dina lineata (O.F. Müller, 1774) (Fig. 2) Localities: Danube at Dunaföldvár (H), km 1560.8, 31. Jan. 1991, leg. WIMMER & NESEMANN; Danube at Szalkszentmárton (H), km 15775.31. Jan. 1991, leg. WIMMER & NESEMANN; Danube near Mühleiten (A), in a dead-water reach "Kühwörther Wasser", Feb. 1989; Danube near Vienna (A), in a dead-water reach "Lusthauswasser", Jun. 1989; Danube-Krumpenwasser, a secondary branch near Stockerau (A), 19. Mar. 1989; March (Morava) near Schlosshof, in a deadwater reach (A), 22. Apr. 1990; Leitha at Pachfurth (A), in a dead-water reach, 2. Jun. 1990, leg. MANN & NESEMANN. The species is widely distributed in the western Palearctic except for the northern parts of Scandinavia. Several easily distinguishable subspecies have been described from Mediterranean countries. All forms detected in the Hungarian Great Plain belong to the nominated subspecies. This leech appears in swampy dead waters of lowland rivers and streams and is occasionally abundant in reed ponds and in the habitats of Salix alba. It becomes more or less common in the main stream of the River Danube downstream Budapest. Hitherto the species has not been reported from upper Danube reaches. Its occurrence in Austria is restricted to dead-water reaches in the east of Vienna. Trocheta cylindrica Örley, 1886 (Fig. 9) Localities: Danube near Alsógöd (H), km 1668.8,6. Mar. 1989, leg. FORRÓ & NESEMANN; Danube near Vác (H), km 1690.4, 6. Nov. 1989, leg. PUKY & NESEMANN; Soroksári Duna near Dunaharaszti (H), 8. Nov. 1989, leg. PUKY & NESEMANN; Szentendre Duna near Szentendre (H), 31. May 1989, leg. PUKY & NESEMANN; Danube and Cuhai-Bakony-ér (H) downstream Gönyü (H), km 1789.8, 3. Apr. 1990; March (Morava) between Markthof and Sierndorf (A), from six samples, Apr.- Aug. 1990; Thaya (Dyje) near Hohenau (A, CS), Aug. 1990. This semiaquatic (amphibious) species is quite separated from Trocheta bykowskii Gedroyc, 1913 regarding its habitat preferences, ecology, geographical distribution and morphology. It is a typical member of the eastern Paleoeuropean fauna. The distribution area is extended from the southern Soviet Union (Georgia, under the name Trocheta subviridis danastrica Stschegolew, 1938) to Greece and from Anatolia into the Pontosarmatian Basin. The range is bordered in the March-Thaya basin, wherein it is a substitute for Dina punctata. The species belongs to the Potamon biocoenosis and prefers muddy river banks. Throughout the investigated area it is restricted to large lowland rivers. Gastropoda Fam. Neritidae Theodoxus danubialis (C. Pfeiffer, 1828) (Fig. 13) Localities: Danube downstream Gönyü (H), km 1783.1, 3. Mar. 1990; Szentendre Duna near Szentendre (H), 31. May 1989, leg. PUKY & NESEMANN; Szentendre Duna between Leáyfalu and Tahitótfalu (H), 31. May 1989, leg. PUKY & NESEMANN; Szentendre Duna at Dunabogdány (H), 31. May 1989, leg. PUKY & NESEMANN; Danube at Visegrád (H), km 1693.6, leg. PUKY & NESEMANN; Mosoni Duna at Dunaszeg (H), 23. Oct. 1990; Danube-"Kühwörther