Chilodonella

(also Chilodon), a genus of protozoans of the subclass Holotricha of the class Infusoria. Several species are free-living inhabitants of freshwaters; Ch. cyprini, an ectoparasite of freshwater fishes that lives on the gills and skin, is widespread. In the USSR it is found in the central, western, and northwestern regions of the European part, as well as in Western Siberia and Altai Krai. The mass development of Chilodonella, which occurs when fish are underfed, produces chilodonelliasis, a severe disease that sometimes results in death. The optimal temperature range for the development of Chilodonella is 5°–10°C. The main preventive and control measures that can be undertaken at fish farms is the provision of sufficient food to fish fry and the administration of saline baths (5 percent NaCl) prior to placement of the fry in hibernating ponds.