The Oligochaete and the Chironomid fauna of the Upper Tisa region and its tributaries
River Tisa and its tributaries serve as a possibility for organisms living in water to migrate as in a corridor. The drifting of different animals is well known, which is a passive way of travelling. Fishes often swim against the stream. Scientific data showed that other animals, too, were able to m...
|Tiscia monograph series
The Upper Tisa valley : preparatory proposal for Ramsar site designation and an ecological background Hungarian, Romanian, Slovakian and Ukrainian co-operation
|Tisza - élővilág, Felső-Tisza-vidék - ökológia
|River Tisa and its tributaries serve as a possibility for organisms living in water to migrate as in a corridor. The drifting of different animals is well known, which is a passive way of travelling. Fishes often swim against the stream. Scientific data showed that other animals, too, were able to migrate against water stream. Invertebrates, such the snail species of Theodoxus fluviatilis (Soós, 1965), a fresh water mussel (Dreisena polimorpha: Mollusca, Bivalvia) or a worm species (Hypania invalida: Annelida, Polychaeta) showed the praxis of this form of migration in recent years. Hypania invalida was first detected in 1969 near Szeged (Ferencz, 1969), and its specimens have become common in River Tisa near Tokaj by present time (Szító, 1996). Different river sections serve as refuges for the species. Following an ecological injury, a species-poor river section will be recolonised by their active and passive migration. There have been no literature sources about the oligochaete and chironomid fauna of the Upper Tisa Region (Pop, 1943, 1950; Albu, 1966), therefore our present data collection will the basis, showing the current situation. The main goals were as follows: to make a data collection which shows the present situation of the species, identifies them, and presents the species-richness of different parts of the river system; to find the character species on different river courses, and to try to qualify the river profiles by indicating the presence or absence of indicator species in the river courses. This work is part of the data collection and evaluation analysing the state of ecological health in River Tisa and its tributaries, and serves as a standard for the assessment of ecological changes in the future (Szító, 1995).