• Parasites, Hosts and Diseases
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• 제60권2호
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• pp.79-96
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• 2022

The infection nature of Clonorchis sinensis metacercariae (CsMc) in freshwater fish hosts is closely related to the transmission of human clonorchiasis. This article reviewed the infection characteristics of CsMc in freshwater fish in the Republic of Korea (Korea). The status of CsMc infection was examined in a total of 17,792 cyprinid fish of 49 species in 9 water systems, which included Hantan-/Imjin-gang, Han-gang, Geum-gang, Mangyeong-gang, Yeongsan-gang, Tamjin-gang, Seomjin-gang, Nakdong-gang, and streams in the east coastal areas from 2010 to 2020. The infection status of CsMc was examined according to cyprinid fish species and water systems, after which analyzed by endemicity and susceptibility index. The high endemicity was shown in the cyprinid fish from 3 regions (6.1%) in the upper reaches of Nakdong-gang, such as Banbyeon-cheon (stream), Yongjeon-cheon, and Wi-cheon. The moderate levels were observed in fishes from 8 regions (16.3%), and low endemicity was shown in fishes from 20 regions (40.8%). No CsMc were detected in fish from 18 regions (36.7%). The susceptibility of CsMc in index fish, Puntungia herzi, was found to be a reliable index without examination of other fish species. CsMc infection rates were closely related to subfamily groups in the cyprinid fish hosts in a highly endemic area. In Korea, a total of 58 fish species in 10 families has been listed as the second intermediate hosts for C. sinensis. This review provides several novel features of CsMc infection and clarifies the species of second intermediate freshwater fish host in Korea.

• 한국수산과학회지
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• 제12권1호
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• pp.65-70
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• 1979

The fish faeona of the Hyeongsan River was found to be as follows; 1. The study of fish fauna for this paper was achieved from May to August in 1978. 2. The collected cyprinid fishes from the Hyeongsan River are 13 species in 10 genera, i. e., Cyprinus carpio, Carassius auratus, Gnathopogon coreanus, Gnathopogon majimae, Pseudorasbora parve, Pungtungia herzi, Moroco oxycephalus, Moroco lagewskii, Triboledon hakenensis, Zacco platypus, Zacco temmincki, Rhodeus ocellatus and Pseudoperilampus uyekii. 3. Among them the 5 species, Pseudorasbora parva, Moroco oxycephalus, Zacco platypus, Rhodeus ocellatue and Pseudoperilampus uyekii, are first described from this river. 4. Zacco temmincki is a dominant species in the whole river and Moroco oxycephalus at the upper, Zacco temmincki at the middle and Carassius auratus at the lower part of the river are dominant species in each studied area. 5. The number of distributed cyprinid species in this river compared to the adjacent river basins is $43.3\%$ of the whole Nakdong River and $118.2\%$ of the Taewha River.

• 한국수산과학회지
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• 제51권4호
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• pp.383-388
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• 2018

Goldfish hematopoietic necrosis (GHN) affects hematopoietic organs and causes high mortality in goldfish. The causative agent of GHN is cyprinid herpesvirus 2 (CyHV-2). The purpose of this study was to detect CyHV-2 in ornamental cyprinid fish. CyHV-2 monitoring was conducted on a monthly basis for 1 year using goldfish Carassius auratus and pearlscale goldfish Carassius auratus that had been cultured at a domestic aquafarm and imported from Singapore, respectively. The results of polymerase chain reaction (PCR) assays using specific primers for the CyHV-2 helicase gene showed that 27.8% of goldfish and 33.3% of pearlscale goldfish were positive for CyHV-2. No cytophatic effects were detected in koi fin or common carp brain cells inoculated with tissue homogenates from either fish. Our data provides the useful data for establishing future quarantine and disinfection policies.

• 한국동물학회지
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• 제23권1호
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• pp.41-48
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• 1980

우리나라 四海岸으루 流入되는 漢江의 上流에서 筆者等에 依하여 發見된 잉어科의 魚類가 지금까지 發見된 돌고기 Pungtungia herzi, 감돌고기 Pseudopungtungia nigra, 쉬리 Coreoleuciscus splendidus 等과 體形, 頭部의 形態, 입술과 수엽의 構造等에 顯著한 差異를 보이므로 本種을 Pseudopungtungia tenuicorpus로 記載하고 韓國名을 가는돌고기로 提唱한다.

• Fisheries and Aquatic Sciences
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• 제25권7호
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• pp.403-408
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• 2022

In April and June 2014, mortalities of goldfish occurred at Korea. The principal signs included pale gills, severely enlarged and softened spleen and kidney and red liver. Moreover, the histopathological characteristics observed mainly in hematopoietic tissues of kidney, gill lamellae and intestine. The predominant histopathological changes were severe necrosis of hematopoietic tissue. In addition, nucleus exhibiting peripherally displaced chromatin were particularly abundant in the kidney of affected fish. The histological examination led to hypothesize the implication of a virus in the mortality. The hematopoietic necrosis herpesvirus (Cyprinid herpesvirus 2, CyHV-2) DNA polymerase gene successfully detected in DNA extracted from kidney and spleen of affected fish using PCR assay and showed 100% identity with already deposited CyHV-2 DNA polymerase gene in NCBI. Artificial infection trials using affected tissues filtrates gave cumulative mortalities of 30% for virus injected goldfish. In the present study, CyHV-2 was detected and identified as the causative pathogen of the epizootic in goldfish in Korea.

• Parasites, Hosts and Diseases
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• 제51권6호
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• pp.703-710
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• 2013

To increase public health awareness for prevention of opisthorchiasis caused by eating raw freshwater fish, the distribution and abundance of Opisthorchis viverrini metacercariae (OV MC) was investigated in freshwater fish obtained from 20 provinces in northeastern Thailand between April 2011 and February 2012. A cross-sectional survey was conducted on 12,890 fish consisting of 13 species randomly caught from 26 rivers, 10 dams, and 38 ponds/lakes. Fish, were collected in each of the rainy and winter seasons from each province. Fish were identified, counted, weighed, and digested using pepsin-HCl. Samples were examined for OV MC by a sedimentation method, and metacercariae were identified under a stereomicroscope. OV MC were found in 6 species of fish; i.e., Cyclocheilichthys armatus, Puntius orphoides, Hampala dispar, Henicorhynchus siamensis, Osteochilus hasselti, and Puntioplites proctozysron from localities in 13 provinces. Among the sites where OV MC-infected fish were found, 70.0% were dams, 23.7% were ponds/lakes, and 7.7% were rivers. The mean intensity of OV MC ranged from 0.01 to 6.5 cysts per fish (or 1.3-287.5 cysts per kg of fish). A high mean intensity of OV MC per fish (>3 cysts) was found in 5 provinces: Amnat Charoen (6.5 cysts), Nakhon Phanom (4.3), Mukdahan (4.1), Khon Kaen, (3.5) and Si Sa Ket (3.4). In conclusion, OV MC are prevalent in natural cyprinid fish, with the infection rate varying according to fish species and habitats.

• Parasites, Hosts and Diseases
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• 제56권3호
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• pp.267-274
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• 2018

Aim of the present study was to provide presence of opisthorchiid metacercariae in cyprinid fish Leuciscus idus in Nura-Sarysu river, Kazakhstan. Infection rate of the ides by the metacercariae was 42%. The metacercariae, similar morphologically to those of the liver flukes, were found: elliptical in shape, $0.19-0.25{\times}0.15-0.22mm$, oral and ventral suckers nearly equal size, and excretory bladder O-shape with black content, occupying posterior part of the body. The metacercariae were divided into 2 groups with differences in size and thickness of cyst wall. Adult flukes were recovered from the Syrian hamsters infected with the opisthorch metacercariae and identified with morphological characters to Opisthorchis felineus and Metorchis bilis. DNA sequences of ITS1, ITS2, and cox1 supported the taxonomic assignment.

• 한국수산과학회지
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• 제51권1호
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• pp.47-53
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• 2018

The presence of pathogens in wild fish is a potential threat to the fish being raised nearby fish farm. Surveillance of these pathogens in the wild is, thus, highly important to keep fish in the farm safe from serious communicable diseases. Fish and crustacean were sampled 4 times at Soyang Lake in 2016. Pathogens for five reportable communicable diseases including KHVD (koi herpesvirus disease), SVC (spring viraemia of carp), EUS (epizootic ulcerative syndrome) and WSD (white spot disease), and parasites were investigated. In Soyang Lake, pale chub Zacco platypus was the most abundant. Forty seven pale chub, 8 Korea piscivorous chub Opsarichthys uncirostris, 3 oily shiner Sarcocheilichthys variegatus wakiyae and 2 crucian carp Cyprinus carassius were investigated for detection of target diseases of fish. Seventeen Caridina denticulata denticulata, 12 Oriental river prawn Macrobrachium nipponense and 1 Chinese mitten crab Eriocheir sinensis were used for detection of WSD. As the result, reportable communicable diseases were not detected in all the freshwater animals. Dactylogyrus was detected in Korea piscivorous chub. Copepoda was also detected in pale chub and Korea piscivorous chub. Metacercaria was detected in the pale chub sampled in September and October. Those were not metacercaria of liver fluke Clonorchis sinensis.

• 한국해양생명과학회지
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• 제3권2호
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• pp.96-100
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• 2018

간흡충(Clonorchis sinensis)은 우리나라에서 인체 감염율이 가장 높은 기생충이며, 이는 담수어류를 중간숙주로 삼는다. 따라서 강 유역에 서식하는 담수어류를 대상으로 간흡충의 메타세르카리아(Clonorchis sinensis metacercariae, CsMc)가 감염되어 있는지를 조사한 연구가 많이 수행되었으나 호수에 서식하는 물고기를 대상으로 한 연구는 거의 없다. 본 연구에서는 주요 인공호수인 소양호, 남양호, 안동호, 춘천호에서 2016년부터 2017년까지 잉어과어류를 채집하여 CsMc의 감염 여부를 조사하였다. 이생흡충류의 메타세르카리아는 남양호에서 채집한 치리 및 붕어와, 소양호에서 채집한 피라미와 끄리에서 관찰되었다. 간흡충에 특이적인 프라이머를 사용하여 PCR을 수행한 결과, 남양호의 치리에서 관찰된 것이 CsMc 이었음을 확인할 수 있었다. 본 연구는 주요 인공호수에 서식하는 잉어과어류에서 CsMc의 감염 실태에 대한 정보를 제공하고 있으며, 남양호의 치리에서 CsMc 감염을 처음으로 보고하고 있다는 것에 의의가 있다.

• 한국수산과학회지
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• 제51권3호
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• pp.248-253
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• 2018

Freshwater farms are primarily located adjacent to rivers and lakes, facilitating the introduction and spread of pathogens into natural systems. Therefore, it is necessary to continuously monitor natural aquatic organisms, the breeding environment, and infection rates by pathogenic organisms. Fish and crustaceans were sampled 4 times in the Geum River estuary in 2016. The samples were analyzed for the presence of pathogens for reportable communicable diseases, including KHVD (koi herpesvirus disease), SVC (spring viraemia of carp), EUS (epizootic ulcerative syndrome) and WSD (white spot disease); parasite abundance was also examined. The dominant fish species were deep body bitterling Acanthorhodes macropterus (21.4%), followed by skygager Erythroculter erythropterus (12.7%). For crustaceans, Palaemon paucidens and Chinese mitten crab Eriocheir sinensis were dominant. Sixty fish and 36 crustacean species were examined for reportable communicable diseases. When using a specific primer set for each disease, PCR analysis did not detect any reportable communicable diseases in the samples. Some instances of Dactylogyrus, copepods, nematodes and metacercaria were detected. However, the PCR results indicated that the metacercaria were not Clonorchis sinensis.