As a series of studies to clarify clonorchicidal substances in body surface mucus of some fresh-water fishes, the substance in the epidermal mucus of Cyprinus carpio was isolated by silica gel column and thin layer chromatography and analyzed for its chemical nature. Wormicidal trial was done in vitro, and the results obtained are summarized as follows: The mucus was extracted by ethyl ether and separated into 4 fractions by column chromatography using benzene as solvent. The second fraction with yellowish red colour among them showed the strongest clonorchicidal effect. The yellowish red fraction obtained by column chromatography was then fractionated into 6 spots by thin layer chromatography with petrol. ether/chloroform(30/70, v/v), and the Rf. 0.714 spot among the 6 spots showed the strongest effect. The Rf. 0.714 spot was further fractionated into 6 spots by thin layer chromatography with benzene/acetone (90/10, v/v), and the Rf. 0.800 spot among the later 6 spots revealed the strongest effect. The Rf. 0.800 spot was chromatographed on column with benzene and 2 fractions were obtained. The second fraction of light brown colour represented the final purified fraction. By these purification procedures, clonorchicidal substance was purified 15-fold with 0.03 percent yield from the mucus of C. carpio, and 10mg of the final fraction killed the cercaria in 26 min, the metacercaria in 115 min, and the adult in 443 min. Infra red and nuclear magnetic resonance spectrometric analysis of the purified substance revealed that the substance belongs to an ethyl ester of unsaturated fatty acid with 2 double bonds, 15 methylene groups and l methyl group.
parasitology-helminth-trematoda ; Cyprinus carpio ; mucus ; toxicology

Diplozoon nipponicum, a monogenean trematode from Cyprinus carpio was described according to the characteristic findings of X-form adult, metrical data, and presence of a pair of sticky glands. It is the first record of the presence of Diplozoon nipponicum in Korea.
parasitology-helminth-trematoda ; case report ; Diplozoon nipponicum ; Cyprinus carpio

Trachelobdella sinensis was found in Cyprinus carpio nudus. The morphological chararacteristics were described. It is the first record of Trachelobdella sinensis in Korea(summarized from text).
parasitology ; Annelida ; Trachelobdella sinensis ; Cyprinus carpio nudus ; case report

As a series of studies on the suitability as a second intermediate host of Clonorchis sinensis, the wormicidal effects of mucus from epidermis of Cyprinus carpio nudus were observed. The results obtained were summarized as follows: On the silica gel thin layer chromatography with the greenish yellow supernatant in acetone:benzene/10:90 as carrier, seven spots were observed in iodine chamber. The spot of Rf. 0.225 value among them disclosed the strongest wormicidal effect on the cercaria, the excysted metacercaria, and the adult of C. sinensis. Meanwhile, no seasonal variations were found in Rf. values and effect of the wormicidal fractions. The wormicidal materials in epidermal mucus of C. carpio nudus and Carassius carassius were compared in their effect, and the former was more effective killing substance than the latter. It seemed that C. carpio nudus could not be proper intermediate host of C. sinensis according to results of the present study, in addition to our previous observation results.
parasitology-helminth-trematoda ; Clonorchis sinensis ; Cyprinus carpio nudus ; toxicology ; mucous substance

As a part of observation on the suitability as a second intermediate host of Clonorchis sinensis, various infection experiments were tried to Cyprinus carpio nudus. The results obtained were summarized as follows: The cercariae which attempted to contact with Cyprinus carpio nudus in the water were observed under the stereomicroscope. After contact, cercariae began to separate its tails from the bodies at 4 minutes increasingly, and then the number ranged to 80 percent at 13 minutes after the encounter. But very few cercariae could actually invade into the epidermis of the fish. When Cyprinus carpio nudus were exposed to a number of cercariae in the beaker, only a few cercariae could invade through the epidermis. Most of the invaded cercariae were killed before forming the cyst. Also rare encysted cercariae were found to be dead within 48 hours. Cyprinus carpio nudus were reared with Parafossarulus manchouricus shedding numerous cercariae in the indoor aquarium. When observed after 12 days, to determine the susceptibility, no metacercaria was found infected. Cyprinus carpio nudus were reared with Parafossarulus manchouricus shedding numerous cercariae in Kimhae lake for 2 months in summer of 1982, in order to check the natural infection. No metacercaria of Clonorchis sinensis was found from the fish. In the cases of control fish, Pseudorasbora parva, numerous cercariae were inspected on the course of invasion through epidermis of the fish under the stereomicroscope. And many metacercariae were also found from the fish whenever they were kept in beaker, indoor aquarium, or the lake for natural infection. The results suggested that Cyprinus carpio nudus might not be proper intermediate host of Clonorchis sinensis.
parasitology-helminth-trematoda ; Clonorchis sinensis ; Cyprinus carpio nudus ; Parafossarulus manchouricus ; cercaria ; biology

The prevalence of Centrocestus formosanus metacercariae was investigated in ornamental fish purchased from a pet shop in Chiang Mai, Thailand, including Carassius auratus (goldfish), Cyprinus carpio (Koi), Poecilia latipinna (Sailfin Molly), Danio rerio (Zebrafish), and Puntigrus tetrazona (Tiger barb). The parasite species was identified by the morphology of worms as well as by a molecular approach using ITS2. The results showed that 50 (33.3%) of 150 fish examined were infected with the metacercariae. The highest prevalence was found in C. auratus (83.3%), and the highest intensity was noted in C. carpio (70.8 metacercariae/fish). The most important morphological character was the presence of 32–34 circumoral spines on the oral sucker. The phylogenetic studies using the rRNA ITS2 region revealed that all the specimens of C. formosanus in this study were grouped together with C. formosanus in GenBank database. This is the first report on ornamental fish, C. carpio, P. latipinna, D. rerio, and P. tetrazona, taking the role of second intermediate hosts of C. formosanus in Thailand. Prevention and control of metacercarial infection in ornamental fish is urgently needed.
Carps ; Databases, Nucleic Acid ; Goldfish ; Metacercariae* ; Parasites ; Poecilia ; Prevalence* ; Spine ; Thailand* ; Zebrafish

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., Metagonimus spp., Pygidiopsis summa, Centrocestus armatus, Metorchis orientalis, M. taiwanensis, Clinostomum complanatum, Echinostoma spp., Stictodora spp., Diplostomum sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. Metagonimus spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, Tribolodon hakonensis, from 5 lakes, and their density was 14.6 per fish infected. P. summa metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. C. armatus metacercariae were detected in 7 (14.6%) T. hakonensis and 3 (15.0%) Tridentiger brevispinis from Hyang-ho, and 5 (19.2%) Acanthogobius flavimanus from Gyeongpo-ho. Stictodora spp. metacercariae were found in 4 fish species, i.e., Tridentiger obscurus, Tridentiger trigonocephalus, Chelon haematocheilus, and Acanthogobius lactipes, from Gyeongpo-ho. Total 15 C. complanatum metacercariae were detected in 2 (9.1%) crucian carp, Carassius auratus, from Songji-ho. M. taiwanensis metacercariae were found in T. hakonensis from Hyang-ho and Gyeongpo-ho and in Pseudorasbora parva from Gyeongpo-ho. Total 11 M. orientalis metacercariae were detected in 3 (6.3%) T. hakonensis from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.
Carps ; Digestion ; Echinostoma ; Fishes ; Gangwon-do ; Goldfish ; Heterophyidae ; Korea ; Lakes ; Metacercariae ; Methods ; Republic of Korea ; Smegmamorpha

Cercariae of Clonorchis sinensis were attempted to penetrate into various fry of fresh water fishes in order to examine the conditions of infection and the further development in the fish. The following conclusions were made. Cercariae of C. sinensis penetrated into the muscle of the fry of Pseudorasbora parva were found to be able to develop. Cercariae penetrated into the fry of Pseudorasbora parva migrated into the organs of the fry to kill their host. From each dead individual of P. parva, more than 10 larvae of C. sinensis could be discovered. Cercariae attached on the Cyprinus carpio, Carassius and gold fish were almost killed before penetration into the body and even one or two cercariae penetrated were also killed as time passed. Cercariae of C. sinensis infected on the fry of Cyprinus Carpio, Carassius auratus and gold fish could not survive more than 60 days. Cercariae penetrated into Cyprinus carpio and Carassius auratus could not develop into complete metacercariae even after 3O days. Cercariae of Clonorchis sinensis penetrated into the fry of Aplocheilus latipes were killed within 10 hours and the cercariae attached on the caudal fin were destroyed in 2 hours. It was found that no cercariae of Clonorchis sinensis could penetrate into the body of the fry of Misgurnus anguillicaudatus.
parasitology-helminth-trematoda-Clonorchis sinensis ; cercariae ; Pseudorasbora parva ; Cyprinus carpio ; Carassius auratus ; gold fish ; Aplocheilus latipes ; Misgurnus anguillicaudatus ; mucous substance

The prevalences of the fluke belonging to genus Metagonimus have been reported along the upper stream of inhabitants by several workers since 1980, however the taxonomical problems of the fluke was not yet settled. The larval flukes; cercaria and metacercaria as well as their intermediate hosts, and adult were studied in order to identify the Metagonimus in the areas. The results obtained are summarized as follows: The snails, Semisulcospira globus were collected from the three different localities along the upper stream of the River. The cercariae were found from 125(7.2%) out of 1,730 snails by natural emerging method, and were identified into 5 species including Metagonimus sp. (3.7%), Pseudexorchis major(1.4%), Cercaria nipponensis (0.9), Cercaria incerta (0.6%) and Cercaria yoshidae(0.6%). Cercariae of Metagonimus species had four to five oral spines on its anterior of the first line. The cercariae of Metagonimus were experimentally exposed to goldfish. Infection rate was 22.9% out of 105 goldfish, and the encysted metacercariae were found in fins(86.7%) and on scales (13.7%) of the fishes, but not in their muscle, head or visceral organs. Seven species of fish were caught in the Daecheong reservoir and the upper stream. Infestations with metacercaria of Metagonimus were found 100% in Opsariichtys bidens and the parasitized numbers of the metacercariae were observed from 250 to 2,400 per fish. In the upper stream, Zacco temmincki, Z. platypus and Pseudogobio esocinus were infected 100% with the metacercaria, on the other hand, the fishes caught in the reservoir showed the lower infestation rates, and a few metacercariae found in the fishes Carassius carassius and Cyprinus carpio in the reservoir and the stream. The majority of metacercariae was detected only on the scales of fishes. In order to know the infectivity and the distribution patterns in the intestine of hosts, rats and dogs were infected with the metacercariae obtained from O. bidens and Z. platypus. In addition the metacercariae obtained from Z. temmincki, P. esocinus and goldfish were given to the rats. The recovery rates of the worms in the small intestine of dogs were higher (63.3-65.8%) than those of the rats (3.5-31.6%). The flukes were found mostly in the middle and the lower part of small tntestine of the rats and the dogs, but no worm was collected in the upper part of the intestine of rats. The size of adult flukes varied by the hosts. In the adult flukes, oral sucker was smaller than ventral sucker, and the right and left testes were located diagonally, the uterine tubules circled around the upper left testis. The average egg size was 29.1 x 17.7 micro-meter. According to the above results, the flukes belonging to genus Metagonimus distributed along the Geum River was concluded to be identical with Miyata type of M. yokogawai as that Saito had proposed.
parasitology-helminth-trematoda ; Metagonimus sp. ; epidemiology ; cercaria ; metacercaria ; Zacco temmincki ; Zacco platypus ; Pseudogobio esocinus ; Opsariichtys bidens ; Carassius carassius ; Cyprinus carpio

The author reported in the previous pager on his observation of sudden death of Clonorchis sinensis cercaria before penetration into the body of fry such as Cyprinus carpio and Carassius auratus. And in these studies, the reason behind the fact was investigated and it was found that the mucous substances on the surface of a certain fishes have a strong wormicidal effect to the larva of C. sinensis. When cercariae of C. sinensis were immersed into the mucous substance of gold fish for three minutes 36 seconds to 4 minutes 20 seconds, into that of Aplocheilus latipes for 4 minutes 30 seconds to 5 minutes 20 seconds, into that of Cyprinus carpio for 5 minutes 15 seconds to 6 minutes l6 seconds, and into that of Carassius auratus for 5 minutes 20 seconds to 7 minutes 30 seconds, it was observed that they were all killed. No wormicidal effect against C. sinensis could be observed with the mucous substance obtained from Pseudorasbora parva, Misgurnus anguillicaudatus and Ophicephalus argus. No wormicidal effect against Metagonimus sp. cercaria is observed with the mucous substance obtained from Cyprinus carpio, Carassius auratus. The wormicidal effect of the mucous substances obtained from gold fish was destroyed when heated over 60 C. The movements of metacercaria of C. sinensis stopped after 10 minutes application of the mucous substance obtained from Cyprinus carpio and they were killed within 30 minutes. When the adult worms collected from the bile duct of experimentally infected rabbits for 20 to 60 days, were immersed into mucous substance from Cyprinus carpio, they were killed between 25 minutes and 35 minutes. No wormicidal effect could be observed with the mucous substance obtained from dead Cyprinus carpio, Carassius auratus, gold fish, when applied to the adult worms and larvae of C. sinensis.
parasitology-helmith-trematoda-Clonorchis sinensis, Metagonimus sp. ; Cyprinus carpio ; Carassius auratus ; Aplocheilus latipes ; Pseudorasbora parva ; Misgurnus anguillicaudatus ; Ophicephalus argus ; gold fish ; mucous substance