• Journal of fish pathology
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• v.23 no.1
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• pp.131-135
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• 2010

Unidentified viral disease with high mortalities has been recorded consistently since 1998 in cultured carp Cyprinus carpio in Korea. In the present study, we investigated the histopathological characteristics of the diseased carp to evaluate the relatedness to koi herpesvirus disease (KHVD). Histopathogical examination revealed severe necrotic changes and vacuous cells in the kidney, spleen, liver, pancreas, heart and intestine, but eosinophilic intranuclear inclusion, a typical characteristic of KHV infection was not detected. These results suggest that KHVD may be not a cause for the high mortality occurring among cultured carp in Korea and possibly other unknown viral disease could are related.

• Journal of fish pathology
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• v.12 no.2
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• pp.101-105
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• 1999

In a survey of net-caged yellowtail Seriola quinqueradiata in the southern parts of Korean Peninsula, we found infestations of ciliate in the gills of the moribund fish during the abnormally elevated temperature. The ciliate was very similar to genus Colpoda Muller, 1773 on morphological and reproductive characteristics. Histopathological changes revealed that the ciliate invaded gills only, causing extensive destruction of the gill filaments including lamella without any clinical signs found in the other organs and tissues. This is the first record of the parasitic ciliate in cultured yellowtail.

• Journal of fish pathology
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• v.15 no.1
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• pp.1-7
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• 2002

On April of 2000 and February of 2001, a disease characterized by darkening, ascites and enlargement of the spleen occurred in flounder, Paralichthys olivaceus, farmed near northern and eastern coasts of Korea. Various degree of necrosis including liquefactive-type was observed mainly in hemopoietic tissue of spleen and kindney. Certain tissue such as branchial soft tissue including epithelium showed a similar necrotic findings. But some tissues such as intentine had several necrotic clusters of wandering cells, being possibly leukocytes. Necrotic evidences of blood cells were evident in various tissues including hemopoietic tissues. Necrobiotic bodies were frequently encountered in blood smear preparations. Bullet type-virious were detected in the spleenic cells. Each virion was about 500 nm in diameter and 170nm in length. From these results, this disease was thought to be a rhabdoviral disease.

• Journal of fish pathology
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• v.25 no.3
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• pp.243-247
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• 2012

Histopathological observations on a epidermal papilloma of wild red halibut (Hippogossoides dubius) caught at the area around Echung Island and Gogunsan Islands were done. The papilloma formed on the dorsal fin was the same color with the body on the ocular side but black on the non-ocular side. Under light microscopy, the tumor on the skin was very similar to epithelial papilloma supported by connective tissue. X-cell-like cells in the tumors were large and eosinophilic with a centrally-located, large nucleus. But the characteristic large nucleolus in the nucleus of the x-like cells was indistinct clear in this specimen because about 6-9 hours have passed after catching the fish and autolysis have occurred.

• Journal of fish pathology
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• v.23 no.2
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• pp.165-176
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• 2010

In May 2007, mass mortality of Israeli carp, Cyprinus carpio L., was occured on a pond farm located in Jeollabukdo Province, Korea. The mortality rates reached up to 2% of the total fish in the farm per day. Typical clinical signs were abdominal distension, reddish foci on the skin, enteritis, liver congestion and enlarged spleen and kidney. On the basis of biochemical characteristics and 16S rDNA sequence, the causative bacteria isolated from affected carp were identified as Aeromonas veronii. Histologically, degeneration of hepatocytes and congestion in sinusoids were observed in the liver. Spleen showed hemorrhage and the destruction of the sheathed tissues. In kidney, necrotized renal tubules and glomerular destructions were observed. Intestinal tissues revealed necrotized and severe hemorrhage. Mass hemorrhage was observed in muscles. This is the first report that A. veronii caused mortality in cultured Israeli carp in Korea.

• Journal of fish pathology
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• v.17 no.1
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• pp.21-28
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• 2004

In late summer of 2001, a new disease "overturn disease" occurred among mud loach (Misgurnus mizolepis) cultured in a farm Chonbuk Province. The fish exhibited a lethargic, erratic and spiral swimming at the water surface. Affected fish showed swollen abdomen with accumulation of air bubbles in the intestinal canal. The bubbles were much larger in the anterior part than in the posterior part. Hematological and histopathological examinations were done. No significant differences were found in RBC count, Ht value and Hb concentration between the diseased and the healthy fish. Gill filaments showed proximal hyperplasia of the respiratory epithelia and fusing of the gill lamella. Hemorrhage and necrosis occurred in the intestinal epithelia and within the lamina propria, and the mucosal epithelia were separated from the muscularis. Hepatocytes underwent atrophy. In the fish experimentally tied between the annal fin and the anus by a thread to confirm accumulation of air bubbles within intestine, accumulation of air bubbles was confirmed. This disease in mud loach appeared to be induced by circulatory disturbances in the intestinal wall owing to accumulation of air bubbles in the alimentary canal after fed high protein diet throughout all culturing period.

• Journal of fish pathology
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• v.20 no.2
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• pp.129-137
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• 2007

Skeletal deformity in hatchery-reared river puffer (Takifugu obscurus) fingerlings occurred. The vertebral abnormality was recognized with naked eyes 80 days after hatching. Affected fish had a good appetite but no clinical signs were found except the vertebral abnormality. As more than 90% of the hatchery-reared fish exhibited vertebral abnormality, the fingerlings could not be used for commercial seeds any more. Morphological changes in the vertebrate and the swim bladder were observed with a soft X-ray. Histopathological changes on the caudal muscle around the deformed vertebrae, gill, and spleen were also examined to clarify the cause of the deformity. Spinal curvature occurred between vertebrae 10 and 12, but any malfunction of the swim bladder was not found. The diameters of the muscle fibers around the deformed vertebrae were much smaller and more irregular than those in normal fish, and the gabs between the fiber bundles were greatly enlarged. No evidence of inflammation response was found in the muscle layer. In the hatchery, feed was putting at the position of water inflow, which might attract the fingerings to move toward the feed in spite of incomplete development of their caudal muscle fibers. From these results, it is suggested that the high speed of water current in rearing aquaria might be associated with the development of vertebral abnormality.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1557-1565
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• 2010

Methyl paraben (MP), which is used as a preservative in pharmaceutical and cosmetic (shampoo) products, foods and beverages, enters into the aquatic environment and can pose a potential fish health hazard. In this experiment, effects of MP were evaluated in adult male common carp (Cyprinus carpio) by exposing them to fractions (1/$143^{rd}$ to 1/29th) of the $LC_{50}$ dose with every change of water for 28 days. Vitellogenin induction, metabolic enzymes, somatic indices and bioaccumulation were studied at weekly intervals. The $96^{th}$ h $LC_{50}$ of MP in fingerlings was 120 mg/L. Compared to the control, except for increases (p<0.01) in alkaline phosphatase (EC 3.1.3.1), alanine aminotransferase (EC 2.6.1.2) and liver size, there were decreases (p<0.01) in activity of acid phosphatase (EC 3.1.3.2), aspartate aminotransferase (EC 2.6.1.1), and testiculosomatic index following exposure to any dose of MP. Vitellogenin induction was significantly higher (p<0.01) in exposed than unexposed (control) fish. The bioaccumulation of MP in testis, liver, brain, gills and muscle tissues of fish increased significantly (p<0.01) with increase of dose from 0.84 ppm to 1.68 ppm. Dose and duration of exposure (p<0.01) indicated that an exposure period of 1 to 2 weeks was sufficient to cause changes in the quantifiable parameters studied. Fish exposed to 4.2 ppm MP became lethargic after the $26^{th}$ d. Histologically, degeneration, vacuolization and focal necrotic changes in liver and fibrosis-like changes in testicular tissue were noted.

• Journal of fish pathology
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• v.9 no.2
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• pp.157-168
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• 1996

In this study, Residue of formaldehyde and histopathological changes in formalin and neutralformalin in treated fish(Sebastes schlegeli) were observed at two different temperatures(15 and $25^{\circ}C$). Immediately after in treatment, residue of formaldehyde in formalin treated fish was show little bit higher than in neutral-formalin treated fish at $15^{\circ}C$. But, there is no difference at water temperature $25^{\circ}C$. The elimination of formaldehyde was markedly temperature-dependent. The approximated withdrawal time were 72hr and 24hr at water temperature 15 and $25^{\circ}C$. Formalin was more toxic than the neutral-formalin at the same condition. Intensity of tissues damage was increased with increasing concentration of chemical and temperature. Formalin and neutral-formalin treatments caused edema and seperation of epithelium, winding of secondary gill lamella, necrosis in the gill ; congestion and pycnosis, vacuolation in the liver ; hydropic and granulated degeneration, necrosis of epithelial cells in the proximal renal tubule ; increasing mucus cells, cracking, necrosis of epidermis and dermis in the skin tissue.

• Journal of fish pathology
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• v.14 no.2
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• pp.81-90
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• 2001

The histological responses of the flounder, Paralichthys olivaceus to copper were examined in the gill, hepatopancreas and kidney. In control group, from 5 weeks mucous cells and chloride cells were increased in the gill, and numerous hemocytes and some melano-macrophagocytes were observed in the hepatopancreas and kidney. The minimum concentration for histological responses was 0.05mg/$\ell$/7d. In this group gill and hepatopancreas showed chloride cell activation, hepatocyte activation, pancreatic zymogen reduction, and congestion, and melanomacrophagocytes were observed in the kidney. From the histological observations, the critical concentrations for dysfunctionality were 0.18mg/$\ell$/21d in the gill, 0.18mg/$\ell$/14d in the hepatopancreas and 0.08mg/$\ell$/14d in the kidney, respectively.