[Studies on the metacercariae from fresh water fishes in the Kum-Ho River]

The distribution and the infestation rates of metacercariae in fishes from the Kum-Ho river were observed from June 1965 to August l967. The results obtained are as follows: 1)The Fourteen kinds of metacercariae; Exorchis oviformis, Metorchis orientalis, Cyathocotyle species, Metacercaria hasegawai, Clonorchis sinensis, Metagonimus species, Pseudexorchis major, Echinochasmus species, Centrocestus species, Prosorhpynchus species, and four kinds of unidentified species, A, B, C and D were detected from 12 kinds of fishes. 2)Clonorchis sinensis, Metagonimus species, Echinochasmus species, and Centrocestus species of the detected 14 kinds of flukes were noted to be parasited in man; Metorchis orientalis and Cyathocotyle species in avian species; and Exorchis ovifomis and Pseudexorchis major in wels, but the definite host of the other 6 kinds of flukes were not identified. 3)Exorchis oviformis was found in 64.5 percent, of all kinds of fishes, Cyathocotyle species in 36.8 percent of 7 kinds of fishes, Metacercaria hasegawai in 36.3 percent of 8 kinds, Clonorchis sinensis in 95.0 percent of 6 kinds and Metagonimus species in 47.9 percent of 10 kinds. 4)Concerning the infested rates of metacercaria and the length of fishes, Exorchis oviformis and Clonorchis sinensis showed increased rate by the length of fishes but the rest of fishes showed no relationship between them. 5)The infested degree of metacercaria of Clonorchis sinensis was highest in Pseudorasbora parva with 34.3 parasites per cubic cm of flesh, of Exorchis oviformis in Carassius carassius with 7.3, of Cyathocotyle species in Acheilognathus with 6.0, and of Metacercaria hasegawai in Pseudogobio esocinus with 5.7 but Prosorhpynchus etc. were very few in all kinds of fishes. 6)The infested rates of metacercaria in the four kinds of fishes, Pseudorasbora parva, Pungtungia herzi, Pseudogobio esocinus and Gnathopogon coreanus seemed not to be influenced by season, Spring and Autumn. 7)In the infested rates of metacercariae by parts of fishes, Exorchis oviformis was chiefly infested in scales and fins; Metorchis orientalis, Cyathocotyle species, Clonorchis sinensis, Pseudexorchis major, Centrocestus species and Prosorhpynchus ecinatus were chiefly infested in muscle; Metacercaria hasegawai in muscle and fins; Metagonimus species chiefly in scales; and Echinochasmus chiefly in gills.