• Parasites, Hosts and Diseases
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• v.56 no.4
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• pp.341-349
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• 2018

The infection status of Centrocestus armatus metacercariae (CaMc) was broadly surveyed in freshwater fishes from major river systems in the Republic of Korea (Korea) during 2008-2017. A total of 14,977 fishes was caught and examined by the artificial digestion method. CaMc were detected in 3,818 (97.1%) (2,114 Z. platypus: 96.1% and 1,704 Z. temminckii: 98.4%) out of 3,932 Zacco spp. examined and their density was 1,867 (2,109 in Z. platypus and 1,567 in Z. temminckii) per fish infected. The prevalences with CaMc were high, 93.7-100%, in Zacco spp. from all surveyed areas. However, their densities were more or less different by the surveyed areas and fish species. They were most high in Nakdong-gang in Gyeongsangnam-do (4,201 in average), and followed by Geum-gang (2,343), Nakdong-gang in Gyeongsangbuk-do (1,623), Han-gang (1,564), Tamjin-gang and Yeongsan-gang (1,540), streams in the east coast (1,028), Seomjin-gang (488) and Mangyeong-gang (170). In another species of rasborinid fish, Opsariichthys uncirostris amurensis, CaMc were detected in 222 (74.8%) out of 297 ones examined and their density was 278 (1-4,480) per fish infected. CaMc were also detected in total 41 fish species except for the rasborinid fish, Z. platypus, Z. temminckii and O. uncirostris amurensis. Conclusively, it was confirmed that among the 3 species of rasborinid fish, Z. platypus and Z. temminckii are highly prevalent and O. uncirostris amurensis is moderately prevalent with CaMc. Additionally, we could know that variety of fish species act as the second intermediate hosts of C. armatus in Korea.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.523-529
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• 2021

The endemicity of zoonotic trematode metacercariae (ZTM) was investigated with total 871 freshwater fishes (19 species) from Deokcheon-gang (a branch stream of Gyeongho-gang) in Sancheong-gun, Gyeongsangnam-do, Korea for 3 years (2018-2020). All fishes were examined with the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 233 (36.3%) out of 642 fish in 11 positive fish species (PFS), and their infection intensity was 27 per fish infected (PFI). Especially, in index fish, Puntungia herzi, of CsMc infection, prevalence was 64.2% and infection intensity was 37 PFI. Metagonimus spp. metacercariae (MsMc) were found in 760 (87.5%) out of 869 fish in 18 PFS and their infection intensity was 228 PFI. In sweet smelt, Plecoglossus altivelis, the prevalence of MsMc was 97.6% and their infection intensity was 3,570 PFI. Centrocestus armatus metacercariae were detected in 209 (29.4%) out of 710 fish in 8 PFS and their infection intensity was 1,361 PFI. Echinostoma spp. metacercariae were found in 293 (42.6%) out of 688 fish in 15 PFS and their infection intensity was 5 PFI. Metacercariae of Clinostomum complanatum and Metorchis orientalis were also detected in 2.7% and 21.2% fish in 4 PFS and their infection intensities were 3.1 and 3.4 PFI respectively. By the present study, it was confirmed that some species of ZTM including CsMc and MsMc are more or less prevalent in fishes from Deokcheon-gang in Sancheong-gun, Gyeongsangnam-do, Korea.

• Parasites, Hosts and Diseases
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• v.59 no.4
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• pp.427-432
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• 2021

The infection status of zoonotic trematode metacercariae (ZTM) was investigated in total 568 freshwater fishes (19 species) from the irrigation canal of Togyo-jeosuji (Reservoir) in Cheorwon-gun, Gangwon-do, the Republic of Korea for 3 years (2018-2020). All fishes were examined using the artificial digestion method. The metacercariae of Clonorchis sinensis (CsMc) were detected in 180 (43.8%) out of 411 fish of positive species, and their infection intensity was 38 per fish infected (PFI). Especially, in 2 fish species, i.e., Pseudorasbora parva and Puntungia herzi, the prevalence was 82.1% and 31.3%, and the infection intensity with CsMc was 88 and 290 PFI, respectively. Metagonimus spp. metacercariae (MsMc) were found in 403 (74.1%) out of 544 fish of positive species, and their infection intensity was 62 PFI. In the pale chub, Zacco platypus, the prevalence of MsMc was 98.6%, and their infection intensity was 144 PFI. Centrocestus armatus metacercariae were detected in 171 (38.9%) out of 440 fish of positive species, and their infection intensity was 1,844 PFI. Echinostoma spp. metacercariae were found in 94 (19.6%) out of 479 fish of positive species, and their infection intensity was 3 PFI. Metorchis orientalis metacercariae were detected in 43 (29.3%) out of 147 fish of positive species, and their infection intensity was 4 PFI. By the present study, it has been confirmed that some species of ZTM, including CsMc and MsMc, are prevalent in fishes from the irrigation canal of Togyo-jeosuji in Cheorwon-gun, Gangwon-do, Korea.

• Journal of fish pathology
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• v.20 no.3
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• pp.249-255
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• 2007

We investigated the phenotypic characteristics by using API20E, APIZYM and determined minimum inhibitory concentrations (MICs) of 7 antibiotics in motile aeromonads isolated from freshwater fishes in Korea and Japan, and 4 American Type Culture Collection (ATCC) strains. All isolates (n=7) were identified as motile Aeromonas species according to API20E test. Lysine decarboxylase activity and acid production from 4 different carbohydrates including mannitol, rhamnose, amygdalin and arabinose were observed in various strains. In enzymatic activities by APIZYM, all isolates showed negative reactions in valine and cystine arylamidases, α-chymotrypsin, α-galactosidase, β-glucuronidase, α-glucosidase, α-mannosidase and α-fucosidase. Although the intensities of each enzymatic activity were diverse in alkaline phosphatase, esterase-lipase, leucine arylamidase, β-galactosidase and N-acetyl-β-glucosaminidase, all isolates showed positive reactions. All isolates were resistant to ampicillin sodium (MIC>100㎍/ml), but sensitive to chloramphenicol (MIC≤1.6㎍/ml). However, recently isolated strains (AC9804, AC0202 and GMA0361) were commonly resistant to tetracycline (MIC=50㎍/ml). Furthermore, AC9804 was resistant to oxolinic acid (MIC=12.5㎍/ml). GMA0361 was resistant to kanamycin sulfate (MIC>100㎍/ml) and streptomycin sulfate (MIC>100 ㎍/ml).

• Journal of fish pathology
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• v.24 no.3
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• pp.247-254
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• 2011

The purpose of this study was to obtain reference data of parameters for hematological health diagnosis in cultured freshwater fish and also evaluate application of automatic dry-type chemistry analyzer (FUJI DRI-CHEM 3000) used to those blood tests. A blood profile of total 200 fish for rainbow trout (Onchorhynchus mykiss), israel carp (Cyprinus carpio), tilapia (Oreochromis niloticus) and eel (Anguilla japonica) cultured in Inland Fisheries Research Institute of NFRDI was determined by hemoglobin (Hb) and plasma chemistry tests: total protein (TP), albumin (ALB), alkaline phosphatase (ALP), blood urea nitrogen (BUN), lactate dehydrogenase (LDH), triglyceride (TG), total cholesterol (TCHO), creatinine (CRE), aspartate aminotransferase (AST), alanine aminotransferase (ALT), glucose (GLU). The values of ALT, TG, LDH, ALB, TCHO, AST and ALP were outside from the minimum and/or maximum of the established detectable range of the analyzer. ALT and TG were not detectable in the range of 67%~61.5%. LDH, ALB and TCHO were not detectable in the range of 36~17%. AST and ALP were not detectable in the range of 5.5~0.5%. However, the values of BUN, CRE, GLU, Hb and TP were below the detectable limits of the analyzer.

• Journal of fish pathology
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• v.9 no.2
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• pp.113-118
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• 1996

During a study to document more fully the parasitic ciliates of Korean freshwater fishes, we found numerous small ciliates in the gills and skin of crucian carp, Carassius carassius. Cursory examination indicated that the ciliate were very similar with Chilodonella sp. In this study, we described the morphometrics of this ciliate in detail and compared with other species of Chilodonella in the world. Numerous small ciliates were observed in the body surface, fins and gills of infected fish and excessive mucus production were seen in those fish. Sometimes ulcer was observed in the body of moribund fish. From the scrutinized observation of the parasite, it was identified as Chilodonella hexasticha. The parasite was dorsoventrally flattened body, without a notch in the posterior margin, and it measured 30-$45{\mu}m$ long and 15-$30{\mu}m$ wide. In number of kineties, the right band ciliature was 3-5 and the left band ciliature was 3-5. The right ventral ciliary band shaped arch and was longer than the left, straight band. It had a single oval macronucleus, 8-$15{\mu}m$ in diameter, a single micronucleus, 2-$4{\mu}m$ in diameter. The cytopharynx was reinforced by 10-16 conspicuous nematodesmata, which shaped like a tube and curved at its inner end. Two contractile vacuoles, one anteriorly at right and the second posteriorly at left were observed in wet mounts. This parasite reproduced by a simple division at $22{\pm}1^{\circ}C$.

• Korean Journal of Ichthyology
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• v.19 no.3
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• pp.225-235
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• 2007

The freshwater fish fauna and physical characteristics of streams in Yeosu peninsula and Geumo Islands were surveyed at thirty nine stations in the period of 2003 and 2005. Most of the streams were short in length and narrow in flowing water width. Main materials of riverbed in most stations were cobble, pebble and gravel; those in the stations adjacent river mouth gravel and sand. In the river type, eighteen stations out of surveyed stations were upstream type: Aa. Thirty nine fish species belonging sixteen families were caught in this survey region. Among them twenty seven species were primary freshwater fishes and nine were peripheral. In the species composition of each family, there were the most species in Cyprinidae and Gobiidae, twelve and ten species, respectively. Endemic species of Korean peninsula in this region were eight species. One exotic fish species, Lepomis macrochirus was found in Yeosu peninsula. Dominant species in each district was Zacco temminckii in Yeosu peninsula, Rhinogobius brunneus in Dolsan Island, Leucopsarion petersii in Geumo island and Oryzias latipes in Gae island. In the analysis of community structure, it was appeared that the community of Yeosu peninsula was the most diverse and stable in this region; as the size of island became smaller, diversity and richness of community decreased. Kichulchoia brevifasciata did not caught in this survey, and it is possible that the species was extincted in this island. Acanthorhodeus gracilis and L. petersii were reported firstly in this region.

• Korean Journal of Ecology and Environment
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• v.52 no.3
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• pp.221-230
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• 2019

Barbel steed (Hemibarbus labeo) is a small freshwater fish species as semi-bottom dwellers distributed in eastern Asia. We carried out characterization of the cytochrome c oxidase subunit I (COI) gene from the mitochondrial DNA of H. labeo in the Sumjin River to identify the phylogenetic location of H. labeo in the genus Hemibarbus and Cyprinidae. Multiple alignment of the 577 bp COI sequence revealed high sequence homology (99~100%) between Seomjin River H. labeo. The nucleotide sequence similarity between H. labeo (HD1) and H. mylodon was 88.91% and that of H. longirostis was 88.81% among the three species found in Korea. In addition, the nucleotide sequence similarities of H. maculatus, H. meditus, H. umbrifer and H. barbus showed 98.97%, 97.20%, 96.87% and 98.85%, respectively. Phylogenetic analysis on seven species of the genus Hemibarbus showed that the H. labeo collected in this study formed two clades. One of which consisted of Hadong, Imsil, Kangjin. The other one formed a step with HD2, HD8 and HD9 of Hadong and the H. labeo reported in Busan, Asan and Seoul, Korea. Phylogenetic position of the H. labeo among Cyprinidae showed 0.143 for the evolutionary distance from Zacco platypus and 0.006 for the H. maculatus. In addition, the genetic position of the H. labeo among 28 species of Cyprinidae was found to be located in Group I, including Gobioninae fishes. The results of this study will provide key genetic information for the taxonomic comparison in Cyprinidae and study of model fish for pollution monitoring in freshwater environments.

• BMB Reports
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• v.41 no.3
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• pp.204-209
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• 2008

The cDNAs encoding glutathione peroxidase (GPx) were cloned and sequenced from the liver of three Chinese carps with different tolerance to hepatotoxic microcystins, phyto-planktivorous silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), and herbivorous grass carp (Ctenopharyngodon idellus). Using genome walker method, a 750 bp 5'-flanking region of the silver carp GPx gene was obtained, and several potential regulatory elements were identified in the promoter region of the GPx gene. The silver carp GPx gene was widely expressed in all tissues examined. Despite phylogenetic analysis, assigning this newly described carp GPx to the group of mammalian GPx2, the carp GPx seems more similar to GPx1 from a physiological point of view. The constitutive expression pattern of the three carp liver GPx gene, shows a positive relationship with their tolerance to microcystins.

• Journal of Power System Engineering
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• v.21 no.2
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• pp.77-82
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• 2017

In the fishing boat, freshwater ice is loaded on the fishroom in advance and it is used for storage of fishes. However, it causes degradation of catches' freshness. Therefore, seawater ice machine on board is necessary for the fishing industry. In this study, seawater ice machine with drum type evaporator was manufactured, and the system was tested under various operating conditions having an influence on the COP and amount of ice produced. The main results are as follow : The COP of the system gets larger when the evaporation temperature and rotation speed of the drum in the evaporator increases. The most effective refrigerant is R22 and the value of the COP was 1.43 times higher than that of R404A. The amount of produced ice increases with respect to increment of the evaporation temperature, while that decreases with respect to increment of the evaporator drum rotation speed.