[Investigations on the occurrence of helminth parasites of Lake Constance]
1989
Oezcelik, A. (Institut fuer Seenforschung und Fischereiwesen, Langenargen/Bodensee (Germany, F.R.)) | Deufel, J.
1. From 1974 to 1976 1219 fishes in Lake Constance (Upper Lake) were studied in respect to the occurrence of helminth parasites. Four species out of 21 that live in different habitats were studied in greater numbers throughout the whole year. These are Coregonus lavaretus wartmanni, Rutilus rutilus, Lota lota and Perca fluviatilis. 2. 31 helminth species including 10 Monogenea, 8 Digenea, 1 Cestodaria, 9 Cestoda and 3 Acanthocephala were found. 3. Monogenea were found at skin and gills, mature Digenea in the gut only, metacercariae mainly in the eyes. Cestodes were found in the gut, bowel and liver, Acanthocephala in the gut only. 4. The occurrence of ectoparasites and metacercariae of trematoda depends on habitat, that of adult trematodes, cestodes, and acanthocephala on food. 5. Growth of fishes was affected by Ligula only. 6. Occurrence of Monogenea, Proteocephalus, and Bunodera were found to be dependent on season (water temperature). 7. Only in some species of parasites the number increased with the age of hosts but did not differ with the sex of fishes. 8. Some parasites e.g. Diplostonum spathaceum tolerate a broad spectrum of hosts while others are restricted to families (e.g. Dactylogyrus species, Diplozoon paradoxum) or even the species (e.g. Tetranochus monenteron, Proteocephalus macrocephalus) of fishes. 9. By fish brood introductions parasites from other waters, formerly unknown in Lake Constance, have been carried in. 10. With the eutrophication of Lake Constance the helminth fauna changed qualitatively as well as quantitatively
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