EXPERIMENTAL-VERIFICATION OF THE EFFECT OF CONSTANT AND CHANGING WATER TEMPERATURE ON THE MICROPOPULATION GROWTH IN GYRODACTYLUS-GOBIENSIS GLASER, 1974 (MONOGENEA) PARASITIZING GUDGEON (GOBIO-GOBIO L)

It has been verified under laboratory conditions that constant and changing water temperature markedly affects the micropopulation growth in Gyrodactylus gobiensis parasitic on the body surface of gudgeons (Gobio gobio L.). At a water temperature of 12-degrees-C, the number of gyrodactylids gradually increased up to the mean value-of 63 specimens per host, which was reached on days 27-28 after experimental infection. At a constant temperature of 18-degrees-C, the parasites completely disappeared from the bodies of infected fishes on days 15-20 p.i. A similar effect was produced by gradually increasing temperature from 12 to 18-degrees-C, while the decrease in water temperature from 18 to 12-degrees-C resulted in an increase in the parasite number.