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: 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. 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. 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. 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. 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. 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. 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.
parasitology-helminth-trematoda- Exorchis oviformis-Metorchis orientalis-Cyathocotyle species-Metacercaria hasegawai-Clonorchis ; epidemiology ; metacercaria

In order to determine the infestation patterns for metacercaria of digenetic trematodes, several kinds of fresh-water and brackish-water fish were caught in River Hyungsan, Kyungpook Province, Korea and examined from March to October in 1983. They were collected by netting, fishig with rod and line, or using the bait of crushed oil cake in transparent plastic bowls, and were dissected into the flesh, scales and fins with tail, and then examined for the presence and infestation density of larval trematodes. Of the 11 kinds of fish examined, the encysted larvae of Exorchis oviformis were found all of them, Metagonimus yokogawai from 9 kinds, Cyathocotyle orientalis, Metacercaria hasegawai and Metorchis orientalis from 6 kinds, and Clonorchis sinensis from 4 kinds in the present study. In the intensity of infestation with Clonorchis sinensis, the Korean shiner, Gnathopogon atromaculatus Nichols et Pope, was the most heavily infected species, the average number of metacercariae per gram of fish flesh being 45.5, followed by the striped shiner, Puntungia herzi Herzenstein 11.6, and Southern top-mouthed minnow, Pseudorasbora parva (Temminck et Shlegel), 9.7. The intensity of infestation with the Metagonimus larvae in 8 species of fresh-water fish was relatively low, and the average number per gram of flesh varied from 0.23 to 9.1. In comparison, the brackish-water fish were more heavily infected and the mean number of cysts per gram of flesh in the sweetfish, Plecoglossus altivelis, was 32.9. The results of this study generally indicate that Clonorchis sinensis and Metagonimus yokogawai infection may occur by consuming raw fresh-water fish caught in the river Hyungsan, Kyungpook Province, Korea.
parasitology-helminth-trematoda ; epidemiolgy ; Metagonimus yokogawai ; Cyathocotyle orientalis ; Metacercaria hasegawai ; Metorchis orientalis ; Clonorchis sinensis ; Gnathopogon atromaculatus ; Puntungia herzi ; Pseudorasbora parva

Recent patterns of infection with digenetic larval trematodes in fresh-water and brackish-water fish were studied in three locations of the river Taewha during the period from April to October 1988, and compared with the data reported previously in the same river. Of 16 species of fish examined, the encysted larvae of Cyathocotyle orientalis were found most frequently from 9 species of fresh-water fish. The metacercariae of Echinochasmus sp., Metacercaria hasegawai and Metagonimus yokogawai were found 8 species, those of Clonorchis sinensis from 7 species, and Exorchis oviformis and Metorchis orientalis from 5 species of fish. The infection rates of fish with C. sinensis metacercariae were not lower than those reported in 1980, wheres their intensity of infection was found lowered in 3 species, Coreobagrus brevicorpus, Gnathopogon atromaculatus, and Puntungia herzi. The infection rates of 3 species of fish with M. yokogawai metacercariae were lower than the results in 1982, while the rate was higher in 2 species, Zacco platypus, and Z. temmincki, and rather stationary in Plecoglossus altivelis. The intensity of infection in several species of fish appeared rather higher than in 1980. the encysted larvae of C. orientalis, Echinochasmus sp., E. oviformis and Metacercaria hasegawai showed variations in infection rates of fish in 1980 and in the present study. It was found that the rate of infection with digenetic larval trematodes in fresh-water fish was still relatively high in the river Taewha, and the metacercarial burden in the fish varied greatly by different fish in 1980 and in the present study.
parasitology-helminth-trematoda ; Cyathocotyle orientalis ; Echinochasmus sp. ; Metacercaria hasegawai ; Metagonimus yokogawai ; Clonorchis sinensis ; Exorchis oviformis ; Metorchis orientalis ; Coreobagrus brevicorpus ; Gnathopogon atromaculatus ; Puntungia herzi ; Zacco platypus ; Z. temmincki

In order to clarify infestation pattern for the encysted larvae of digenetic trematodes from fresh-water fishes, this survey was carried out from March to September, 1983. A total of 380 fishes of 32 species were collected with netting at the three reaches, upper, middle and lower in Mangyeong riverside area. After the fishes were dissected into small scraps, they were pressed under cover glass and examined for the presence of those of digenetic trematodes with a microscope. The results obtained were as follows: Out of a total of 380 fishes inspected, 320 fishes (84 percent) from 31 species were found positive with digenetic trematode metacercariae; more than 10 species of the metacercariae were detected in Pseudorasbora parva; Gnathopogon majimae, Microphysogobio yaluensis, Cultriculus eigenmanni and Gnathopogon coreanus (more than 8 species); Aphyocypris chinensis(8 species) and etc. respectively. Clonorchis sinensis metacercariae were found positive from 93 fishes (25 percent) from 12 species detection rates in other species of digenetic trematode metacercariae from various fishes were; Exorchis oviformis, 261 fishes (57 percent) from 28 species; Cyathocotyle orientalis, 47 fishes (12 percent) from 12 species; Metorchis orientalis, 21 fishes (6 percent) from 12 species; Metagonimus yokogawai, 164 fishes (43 percent) from 26 species; Pseudexorchis major, 71 fishes (19 percent) from 18 species; Metacercaria hasegawai, 77 fishes (20 percent) from 25 species; Centrocestus armatus, 24 fishes (6 percent) from 7 species; Echinochasmus japonicus, 2 fishes (0.5 percent) from 2 species, and unidentified species, 34 fishes (9 percent) from 15 species respectively. The sums of average number of the encysted larvae of all species found in fish body/gram showed 83 in P. parva, Cobitis taenia (74.2), A. chinensis (28.5), Pseudoperilampus uyekii (26.6), G. majimae (19.6) and etc. respectively and the average peak number of each metacercaria in fish body/gram showed 21.7 C. sinensis, 24 E. oviformis , 15.3 M. orientalis and 6.1 E. japonicus in P. parva ; 42.7 C. orientalis and 25.1 M. yokogawai in C. taenia; 8.3 C. armatus and 8.3 M. hasegawai in P. uyekii; 6.3 P. major in Carassius carassius, and 2.9 unidentified species in G. majimae respectively.
parasitology-helminth-trematoda ; Clonorchis sinensis ; epidemiology ; Pseudorasbora parva ; Gnathopogon majimae ; Microphysogobio yaluensis ; Cultriculus eigenmanni ; Gnathopogon coreanus ; Aphyocypris chinensis ; Cyathocotyle orientalis ; Metorchis orientalis ; Exorchis oviformis ; Metagonimus yokogawai ; Pseudexorchis major ; Metacercaria hasegawai ; Centrocestus armatus ; Echinochasmus japonicus

The present study was undertaken to determine the pattern of infestation with the encysted larvae of digenetic trematodes in freshwater fish collected in both the natural and fish breeding ponds in Kyungpook Province, Korea. The fish collected in the two natural ponds, Nass-chil, and Sa-il, and three fish breeding ponds, Deok-dong, Mo-gok, and Seongryu-tunnel, were examined from July 1980 to August 1981. The data were compared with the results obtained from freshwater fish caught in the river Kumho by Hwang and Choi(1980). Ten species of fish caught in the ponds were examined for the presence of the larval trematodes. Seven species of the larvae, Clonorchis sinensis, Cyathocotyle orientalis, Echinochasmus species, Exorchis oviformis, Metacercaria hasegawai, Metagonimus yokogawai, and Metorchis orientails and two kinds of undetermined cyst A and B were found. The infestitation rate for Clonorchis sinensis metacercaria in the Korean shiner, Gnathopogon atromaculatus collected in the natural ponds was higher than the rate in the river Kumho by Hwang and Choi(1980), but lower in the fish collected in the breeding ponds. By contrast, the infestation rate in the flat bitterling, Paracheilognathus rhombea in ponds was higher, while there was no change of the rate in the southern top-mouthed minnow, Pseudorasbora parva. The intensity of infestation, expressed as the average number of Clonorchis sinensis metacercaria per gram of flesh, were lower than in the bullhead, Coreobagrus brevicorpus, and Gnathopogon atromaculatus in the ponds in 1981. The intensity was higher in Paracheilognathus rhombea, but no fluctuation in the intensity of infestation in Pseudorasbora parva was observed. The infestation rates and densities for the encysted larvae of digenetic trematodes except for Clonorchis sinensis varied from fish to fish. However, it was found that the rate and intensity of the larval trematodes from all the fish in the ponds was lower than from those in the rivers in Kyungpook Province, Korea.
parasitology-helminth-trematoda ; Clonorchis sinensis ; Cyathocotyle orientalis ; Echinochasmus species ; Exorchis oviformis ; Metacercaria hasegawai ; Metagonimus yokogawai ; Metorchis orientails ; Pseudorasbora parva ; Coreobagrus brevicorpus ; Gnathopogon atromaculatus ; Paracheilognathus rhombea ; Carassius carassius ; Coreoperca herzi ; Cyprinus carpio ; Lipomis macrochirus ; Moroco oxycephalus ; Zacco platypus ; epidemiology