L. Forró szerk.: Miscellanea Zoologica Hungarica 7. 1992 (Budapest, 1992)

Nesemann, H.: Species composition and zoogeography of the invertebrate fauna at the lower reaches of the Lajta River

Glossiphonia concolor (Apathy, 1888) Localities: Mosonmagyaróvár (Ungarisch-Altenburg) 3. 4. 1991 (H); Rét-árok (Leithakanal) 11. 9. 1989, 30. 7. 1991 (A/H); Gattendorf (Lajtakáta), in a small pond near the river 30. 6. 1991 (A); Rohrau, in secondary branches from numerous collections 1990-1991 (A); Gerhaus 10. 5. 1991 (A); Pachfurth, in a secondary branch "Unterer Auwinkel" 2. 6. 1990 (A); Pachfurth, in small deadwater reaches 2. 6.1991 (A); Bruck, in secondary ranches, 16. 7.1991 (A). G. concolor belongs to the pontomediterranean fauna. In general, its distribution pattern in the Danube basin resembles that of Viviparus acerosus. The north-western border of its area is in the Vienna and Kisalföld plains. The species settles abundantly the rivers and streams of the Danubian lowlands (Nesemann 1990b). In the Lajta, G. concolor was recorded frequently from various water bodies of the floodplain throughout the lower and middle reaches. It appears as far upstream as Götzendorf. Glossiphonia paludosa (Carena, 1824) Localities: Mosonmagyaróvár (Ungarisch-Altenbug) 3. 4. 1990 (H); Lajta-megyei-csatorna (Komitatskanal) near Nickelsdorf (Miklóshalma) 2.1989, 9.1991 (A/H). G. paludosa, as well as G. concolor, originates from the pontomediterranean fauna. This species is strongly restricted to lowland rivers with a moderate velocity of flow. It occurs abundantly in the Pannonian reaches of the Danube, being completely absent from the upper river basin. In the Lajta, G. paludosa only reaches the Kisalföld, whereas the Danube is settled as far upstream as the Vienna plain. Hebbdella stagnalis (Linnaeus, 1758) Localities: Lajta at the confluence with the Mosoni-Duna 6. 9.1991 (H); Mosonmagyaróvár Ungarisch-Altenburg 3. 4. 1990 (H); Rét-árok (Leithakanal) 11.9. 1989, 30. 7. 1991 (A/H); Nickelsdorf (Miklóshalma) 26.10.1990, 23. 6.1991 (A/H); Gattendorf 30. 6. 1991 (A); Gattendorf, in a small pond near the river 30. 6.1991 (A); Rohrau, in secondary branches 14. 5.1991 (A). The distribution pattern resembles that of Glossiphonia complanata. H. stagnalis lives in all types of permanent water bodies of the floodplain of the Lajta. Hemiclepsis marginata (O. F. Müller, 1774) Localities: Rohrau, in a secondary branch 14. 5. 1991 (A); Brack, in a secondary branch 16. 7. 1991 (A). This species belongs to the fauna of secondary branches. It is a typical faunal member of slowly running rivers of the lowlands and is widely spread throughout the Danube basin. Alboglossiphonia heteroclita (Linnaeus, 1761) Locality: Rohrau, in a secondary branch 14. 5.1991 (A). A. heteroclita was collected from one locality. The distribution area includes the western Palaearctic region (Sawyer 1986). In the lowlands of the Danube, it appears frequently in all rivers. Theromyzon tessulatum (O. F. Müller, 1774) Localities: Mosoni-Duna at Mosonmagyaróvár (Ungarisch Altenburg) 13. 9.1991 (H); Rét-árok (Leithakanal) 11. 9. 1989 (A/H); Lajta-megyei-csatorna (Komitatskanal) near Nickelsdorf (Miklóshalma) 2. 1989 (A/H); Gattendorf (Lajtakáta), in a small pond near the river 30. 6.1991 (A); Brack, in a secondary branch 16. 7.1991 (A). This species sucks blood from the nose of birds. It prefers the slowly running reaches of rivers and their adjacent backwaters (Soós 1967).