• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.3
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• pp.121-124
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• 1980

Microscopical studies of Leucothrix sp. and its histological effect on the gill tissue of Penaeus japanicus have been made. Infection of Leucothrix sp. results in color change of the gills of the shrimp which is mainly due to the brown or black pigments of the filamentous bacteria. Higher degree of the infections makes necrosis and serious histological changes of the gill tissue and this infection affects the respiratory activity of the shrimp.

• Fisheries and Aquatic Sciences
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• v.5 no.1
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• pp.75-78
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• 2002

The effects of Coehlodinium polykrikoides on the gill of red sea bream, Pagrus major, were examined to clarify the ichthyotoxic mechanisms of this plankton species. The gill of fish exposed to dense blooms over 3,000 cells/mL for 24 h showed severe epithelial separation: a severe edema was found in the secondary lamellar epithelium and interlamellar regions of primary filament. In addition, lipid peroxidation of gill tissue in Coehlodinium-exposed fish was about 2.5 times higher than that of control. The composition of glycoproteins in the gill mucus of Coehlodinium-exposed fish was also changed. These results suggest that the loss of structural integrity of cell membranes in fish gill may be deeply involved in fish death by C. polykrikoides.

• Korean Journal of Ichthyology
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• v.25 no.1
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• pp.1-8
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• 2013

Rockfish, Sebastes schlegeli (total length; $10.36{\pm}0.49cm$, total weight; $16.28{\pm}1.86g$, N; 290) were exposed to various concentrations of naphthalene for 28 days. Exposure concentrations of naphthalene established control, ethanol (solvent) control, 0.5, 1.0, 1.5 and 2.0 mg Nap $L^{-1}$. After exposure, We observed survival rate, and degree of tissue change (DTC) in gill under optical microscopy. Survival rate of the rockfish was more than 90% in control, ethanol control, 0.5 and 1.0 mg Nap $L^{-1}$, whereas it decreased in 1.5 and 2.0 mg Nap $L^{-1}$ (respectively 80%, 62.2%). In histological observation of gill, hyperplasia of epithelial cells observed in all exposure groups. But no showed increase of DTC which was related to concentration. Whereas, DTC at fusion of gill lamellar, lamellar telangiectasia, stasis, aneurysm and necrosis showed dose dependent increase. Especially, fusion of gill lamellar, lamellar telangiectasia and stasis observed at more 1.0 mg Nap $L^{-1}$, and aneurysm and necrosis at more 1.5 mg Nap $L^{-1}$. These results showed naphthalene caused survival and severe change to the gill of the rockfish which was related to exposure concentration.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.4
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• pp.1068-1075
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• 2016

The suitable temperature and salinity for the long-distance transportation for the rockfish were investigated by assessing survival rate, metabolism, histological change. All experimental groups showed survival rates of 100%. Daily Oxygen consumption rhythm was decreased during nights and increased during days. Average oxygen consumption was significantly decreased as temperature and salinity were decreased. Ammonia excretion was significantly increased as temperature and salinity were decreased. Histological changes were observed in the skin and gill of the rockfish exposed to 10 psu under all the temperature conditions, with larger changes at $4^{\circ}C$. Further, nucleus deformation and uniformity in the cytoplasm were also observed.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.49-55
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• 1999

Mass mortality of the horned turban shell, Batillus cornutus was investigated using histological and bacteriological methods. Some pathogenic bacteria were isolated from mortal or inactive individuals. The pathogenic agents causing mortality of the horned turban shells were as Vibrio alginolyticus and V. anguillarum. Laboratory experiment indicated that optimal growth temperature of two bacteria was 25 to 30$^{\circ}C$ and 3% of NaCl. Histological examination of the horned turban shells showed that gill necrosis is one of the major symptom of infected individuals. It was believed that sudden increase of those two bacterial agents due to environmental change cause mortality of horned turban shells.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.133-140
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• 2004

The histopathologieal effects of his(tri-n-butyltin)oxide (TBTO) on the flounder, Paralichthys otivaceus were examined by means of histological methods. The experimental fishes were exposed to 0.17, 0.36, 0.60, 3.20, 6.30, 12.50 ${\mu}g \;L^{-1}$TBTO concentrations for 42 days. Histopathological change of the fish exposed to TBTO is dependent on the exposure duration and concentration. In the lower concentrations early histological changes included activated mucous cells and chloride cells, capillary hyperemia and epithelial hyperplasia in the gill; hepatocyte activation, degeneration of bile duct and pancyeatic zymogen reduction in the hepatopancreas; and capillary hyperemia, appearance of eosinophilic cell and melano-macrophagocytes in the kidney. At the higher concentrations histological changes of dysfunctionality included epithelial lifting and deformation of the lamellae in the gill; pycnosis and cytoplasmic degeneration of hepatocyte; pycnosis of haemopoietic cell and deformation of renal tubules and glomerulus in the kidney. It is indicated that TBTO induced histopathological changes in the fish as other aquatic pollutants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.828-836
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• 1996

The histological changes of gill, liver, spleen and muscle, and respiration and blood variables and liver glycogen content were examined in black seabream, Acanthopagrus schlegeli. Fish were exposed to a high level of total ammonia nitrogen (10.4 mg/l) and recovered from exposure $(0.4{\pm}0.2mg/l)$ in a closed recirculating seawater system. In the process of exposure, mortality was $9\%$, and hyperplasia, necrosis or inflammation appeared in all tissues except for muscle. Oxygen consumption was decreased by $49\%$, and red blood cell (RBC) number, hematocrit and hemoglobin concentration were significantly decreased, while plasma glucose contents, activities of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT) increased. Liver glycogen content significantly increased from $6.6\%\;to\;10.4\%$. A large amount of hemosiderin was observed in the splenic tissue. During the recovery period, RBC number, hematocrit, hemoglobin concentration, GOT and GPT activities were returned to the normal status. Histological status of liver tissue was returned to the normal, but liver glycogen content was not recovered. During the recovery period, spleen melanin-macrophages temporarily increased, but subsequently decreased to the normal status.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.225-232
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• 2013

This study looked into recovery rate and histological changes in the gills of juvenile abalone Haliotis discus hannai by exposure time (3, 6, 12, 24 and 48 h) of different water temperatures (15, 20 and $25^{\circ}C$) and salinities (30, 25, 20 and 15 psu) to understand reasons for the death of abalone exposed by low salinity water. In each water temperature, abalone spats that were exposed to low salinity water (less than 20 psu) for over 6 hours showed decrease in survival rate during recovery and those were exposed at the salinity of 15 psu for more than 24 hours all died. Histological observation showed expansion or damage of gills of the species which were exposed at less than 20 psu for over 6 hours. In case of abalones exposed at the salinity of 15 psu for over 24 hours, most gill tissues were destroyed. This result was glaringly obvious at a higher water temperature, lower salinity and longer exposure time. Accordingly, suffocation caused by damage of gills considered one of direct causes of the death.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.87-96
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• 2006

Reproduction and organ system of the oily bitterling, Acheilognathus koreensis in Isa stream were investigated by means of histological methods. Sex ratio was observed 1 : 1 in female to male. The gonadosomatic index (GSI) of the female showed two peak in December and April. The ovipositor length index (OLI) represented irregular change. From the histological analysis of the organ system, epidermal atrophy and hyperplasia of pigment cell were observed in the skin. Epithelial layer lifting of the lamella and bifurcation of the filament were observed in the gill. Also histological changes as congestion, cytoplasmic degeneration of hepatic cell, glomerular dilatation, hyaline droplet degeneration of renal tubule epithelium and pycnosis of interstitial cell were identified in the liver and kidney, respectively.

• Environmental Analysis Health and Toxicology
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• v.21 no.2 s.53
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• pp.115-126
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• 2006

This study was conducted to find out survival rate, activity, growth and change of the organ structure of bivalves exposed to heavy metal. The results of the study confirmed that zinc (Zn) induces reduction of survival rate and activity, abnormality of organ structure of the equilateral venus, Gomphina veneriformis. Experimental groups were composed of one control condition and three Zn exposure conditions ($0.64mg\;Zn{\iota}^{1},\;1.07mg\;Zn{\iota}^{-1},\;1.79mg\;Zn{\iota}^{-1}$). As the concentration of zinc increased the accumulation of lipofucin increased in the digestive gland. Survival rate was the lowest in the lowest Zn exposure group at $0.64mg;Zn{\iota}^{-1}$. Growth was not significantly different between the control and exposure group. Activity. with the exception of the lowest Zn exposure group at $0.64mg\;Zn{\iota}^{-1}$, was similar between the control and exposure group. Histological analysis of organ system illustrated expansion of hemolymph sinus, loss of striated border of inner epidermis, increase in the number of mucous cell in the mantle. Also, histological degenerations as epithelial necrosis and hyperplasia of mucous cells are recognized in the gill and foot.