• Journal of fish pathology
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• v.23 no.3
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• pp.399-407
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• 2010

On the inner side of each operculum of the crucian carp, Carassius auratus (n=10), the leech, Limnotrachelobdella sinensis of 1-4 individuals were parasitic. The leeches had approximately 41.0 mm in total length and 11 mm in width. These body was composed with anterior sucker, neck, trunk and posterior sucker and average length was 2.3 mm, 7.2 mm, 23.3 mm and 8.7 mm respectively. To both sides of the trunk lateral vesicle of 11 pair existed. When observed by SEM, anterior sucker was hemisphere shape and the mouth where proboscis comes out existed with the its center. Proboscis was connected the esophagus directly. Under light microscopy, bloodsucking gill of C. auratus showed lamella fusion, hypertrophy the epithelial cell of the filament and lamella, increased mucocytes and congested capillaries. On the other hand, necrotic and hydropic degeneration epithelial cell of the lamella, and infiltration of the macrophages from some individuals were suggested the secondary infection with the bacteria or virus after bloodsucking activity of the leech.

• Journal of fish pathology
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• v.10 no.1
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• pp.53-63
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• 1997

In this study, poikilocyte rate and histopathological observation of flounder, Paralichthys olivaceus, treated with formalin, neutral-formalin(0, 50, 100, 150, 200, 300 ppm) at two different temperatures (15 and $25^{\circ}C$) were conducted to determine the time need for recovery. In all test chamber, formalin was more toxic than neutral-formalin and moderate lesions were not observed at low concentration of formalin and neutral-formalin(50~100 ppm). As expectedly, time need for recovery of gill and kidney tissues was lengthening as increasing chemical concentration and temperature. Treatments caused edema, winding of secondary gill lamella, seperation of epithelial layer and thrombosis of secondary gill lamella in the gill; edema, hydropic and hyaline droplet degeneration in the kidney. Representatively, recovery period of fish gill that had been exposed to 300 ppm formalin and neutral-formalin was about 120 and 72 hr($25^{\circ}C$). 72 and 48 hr($15^{\circ}C$). Recovery period of kidney was about 72 and 48 hr($25^{\circ}C$), 48 and 48 hr($15^{\circ}C$) respectively. Maximum value of poikilocyte rate(27.84%) was shown in formalin 300 ppm treated fish at $25^{\circ}C$. Tendency of decreasing poikilocyte rate was similiar to recovery of tissues in treated fish.

• Applied Microscopy
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• v.34 no.2
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• pp.139-143
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• 2004

The ultrastructure of the gills of Oplegnathus fasciatus was examined by means of light and transmission electron microscopes. The gills have primary and secondary filaments (lamellae). The following cells are identified and described : epithelial cell, pillar cell, chloride cell and mucose cell. The simple epithelial layer consists of squamous epithelium containing a large nucleus and the surface is covered with some of microridges. The lamella pillar structures are characterized by axial microtubules and lateral membrane interdigitations. Chloride cells contain a lot of mitochondria and specifically developed tubular systems. The rough endoplasimic reticulum and golgi complex, and some of mucous granules were observed in immature mucous cells. The mature mucous cells were AB-PAS positive, globular in shape, and had mucous granules of similar size with various electron densities.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.699-705
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• 1999

The effects of iron on gill tissue and metabolic rate represented by oxygen consumption of olive flounder, Paralichthys olivaceus were determined. The effects were further studied by means of survival rate of the fish exposed to a serial concentrations of iron. The olive flounder exposed to iron concentrations over 0.93 mg/$\ell$ showed curvature and terminal clubbing of gill lamellae at 2 weeks post-exposure. In iron concentration 4.89 mg/$\ell$, gill of the fish were seriously damaged just after 2 weeks, showing hyperplasia of filament epithelia, deformation of lamella epithelia, chloride cell damage, and separation of lamella epithelial layer, Gills exposed to 9.78 mg/$\ell$ iron concentration resulted in fusion and necrosis of the lamellae after 2 weeks. Significant decreases of metabolic rate of the fish were observed after 4 weeks at iron concentration 0,93 mg/$\ell$ and after 2 weeks at iron concentrations over 4.89 mg/$\ell$. Survival rate of the olive flounder decreased significantly after 4 weeks at the iron concentration over 4.89 mg/$\ell$. These results lead us to conclude that, as far as the iron effects are concerned, its concentrations should not exceed at least more than 0.93 mg/$\ell$ in the fish farm and coastal waters for normal growth of the olive flounder.

• Journal of fish pathology
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• v.6 no.1
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• pp.65-70
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• 1993

The delicate histological structure of gill in teleosts can be easily affected by a variety of biological, chemical or physical detrimental agents because it is directly exposed to the surrounding water. The epithelium of secondary lamella is thin to allow efficient gaseous exchange and this also renders it particularly vulnerable to various pathogens. As well as the main respiratory role, the gill has other various important functions such as acid-base balance, osmoregulation or the excretion of nitrogenous waste products. Thus destruction of epithelial integrity such as epithelial necrosis or thickening can render a fish very vulnerable to respiratory, secretory and excretory difficulties. This article was tried to describe in detail the common processes of pathological responses correlated to the normal histological structures of the gill in teleosts.

• Journal of fish pathology
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• v.21 no.1
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• pp.67-79
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• 2008

This study was conducted to find out biological response of bivalves exposed to tributyltin chloride(TBTCl). The results of the study confirmed that TBTCl induce the reduction of oxygen consumption rateand histopathological feature in the gill structure of equilateral venus, Gomphina veneriformis. The experi-mental groups consisted of a control and 3 TBTCl exposure groups (0.4, 0.6 and 0.8 yg TBTCl L') and theexperimental period was 36 weeks. For histological analysis, gill tissues were fixed in Bouin's fluid andthen stained H-E stain, AB-PAS (PH 2.5) reaction and Masson's trichrome stain after having serially sec-tioned the tissue by paraffin method at thickness of 4-6 (an. The oxygen consumption rate was not signifi-cantly different between the control and exposure groups at 4 weeks, but in all exposure groups at 28 weeks,it was significantly different to the control. Gill of G. veneriformis had demibranch that attached two sheetsof lamellae and a lamella was composed of numerous filaments, numbering 25 on average. The frontal fila-ment zone had three types of cilia; frontal, latero-frontal and lateral depending on locations while the lateralcilia were the longest and largest in number. The mucous cells observed in filaments were more abundant in(542c) in AB-PAS (PH 2.5) reaction. Gill exposed to TBTCl was extended hemolymph sinus and increased hemocytes at 4 weeks, and then it showed increases of mucous cells and partially disappearance of frontalcilia. In the group of 0.8 yg TBTCl L' at 12 weeks, hypertrophy of frontal and latero-frontal epithelia wasobserved. Also it observed m decrease of mucous cell containing weekly acid mucosubstance and appearedpartially destruction muscle fiber bundle, In the groups of 0.4 and 0.6 ug TBTCl L' at 36 weeks, it appearedpartially modification of epithelia and in 0.8 us TBTCl L' group, observed filaments that come out chiti-nous rod from disappearance of frontal and latero-frontal epithelia.

• Journal of fish pathology
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• v.32 no.2
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• pp.81-89
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• 2019

As an epidemiological survey, mortality of marbled rockfish, Sebastiscus tertius observed from a fish farm in Gyeongnam province of South Korea. The major macroscopic sign of the diseased fish was severe multifocal dermal ulceration. Histological observation revealed inflammation, necrosis and colonization of bacteria in various tissues (gill, liver, spleen and kidney). Bacteria was isolated from spleen and kidney in moribund and mortality fish. Seven bacterial isolates from the diseased fish were identified as Aeromonas salmonicida subsp. salmonicida using API 20E and 20NE, API 50CH API ZYM system. Under light microscopy, infected marbled rockfish showed the lifting of the lamella epidermal layer, edematous changes and hypertrophy of epithelial cell in the gill filament. The atrophy of the mucosal fold, erythema in the intestine, and the necrosis of hematopoietic tissue and renal tubule cells with karyolysis were observed in the kidney. In this study was demonstrated the histological reaction of red marbled rockfish infected by Aeromonas salmonicida. Furthermore, this is the first account of extensive dermatitis in Sebastiscus tertius due to atypical A. salmonicida infection, which has high potential in aquaculture among native fish species.

• Journal of fish pathology
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• v.35 no.2
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• pp.231-239
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• 2022

In this study, imported ornamental goldfish (Oranda and black moor) with high mortality was investigated with histopathological analysis. Fishes showed clinical symptoms characterized by gill necrosis and cumulative mortality ranging from 60% to 90% within a month after import from Thailand and China in 2021. CyHV-2 was detected in gill, kidney, spleen and liver of goldfishes. Histopathological analysis revealed epithelial necrosis, intranuclear inclusion bodies associated with viral symptoms in epithelial cell, macrophage infiltration and vacuolation in secondary lamella. In addition, disseminated granuloma formation was observed in various organs such as kidney, heart and mesenchymal membranes. These lesions refer to coinfections with CyHV-2 and other pathogens that cause chronic inflammation, which leads to mortality. Therefore, early disease monitoring needs to reduce the mortality when ornamental goldfish is imported.

• Journal of fish pathology
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• v.5 no.2
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• pp.93-118
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• 1992

The research was carried out to examine the chronic toxic effects of nitrite on the Japanese eel, Anguilla japonica by neans of histological observations. Young eel, 10.8g mean body weight. were exposed to 6 different concentrations of nitrite(1, 5, 10, 20, 30 and 40ppm) for 10 weeks. Each concentration was treated under 5 different levels of pH(5.5, 6.0, 6.5, 7.0 and 7.5) and each of these treatment was tested at 2 different temperature regimes($25^{\circ}C$ and $30^{\circ}C$). Proper concentration of nitrite was made by $NaNO_2$ and proper pH levels were made by the combinations of 0.1M $KH_2PO_4$ and 0.1M $NaHCO_3$. Histopathological test of gill tissues were made along with the test of the formation of thrombocystes and chloride cells on the gill filaments. At the lower pH levels, mucus secretion from the gill was incrased as the nitrite concentration increased. As the level of nitrite increased the number of chloride cells on the gill filament were decreased. Most of the remained chloride cells were observed only at the terminar part of the gill filament at 40ppm of nitrite. Degeneration of gill tissues were observed when nitrite levels were over 10ppm along with detachement and sweption of the epithelial cells of the gill lamellae. Shrunken gill lamellae and formation of thrombosis in the capillaries of gill lamellae were also observed. When temperature goes higher at the higher level of nitrite, necroses in the gill lamellae was increased. At the lower than 10ppm of nitrite, degeneration of gill lamellae was occured at the beginning of the test period but regenerated later. Negative effects of nitrite on the growth of young eel was started between 5~10ppm at the pH level of 7.0 and 7.5. Thrombosis formation were also started at this level. The safety concentration of nitrite at the pH levels of 7.0 and 7.5 on the small eel seems to be 1ppm. Thrombosis and gill lamella detachment and necrosis in the gill capillaries were not observed at this level. Chloride cells were appeared the whole part of the gill filament.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.809-814
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• 1995

The acute and subacute toxicity of fumomsin $B_1$ was evaluted in fingerlings of common carp, Cyprinus carpio. Dipping of fish for acute toxicity was performed for a period of 48 hours, and the $TLm_{48h}$ value(median tolerance limit) was more than 1000 ppm in common carp. Severe damages were observed in various organs and among them, clubbing of gill lamella, lytic degeneration and vacuolation of liver cells, and epithelial edema of renal tubules were relatively prominent. The most significant changes were hyperbasophilic foci of liver cells in subacute toxicity test and these can imply the possibility of hepatocarcinogenecity of fumonisin $B_1$.