• Journal of fish pathology
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• v.10 no.1
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• pp.45-52
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• 1997

A protein-bound polysaccharide preparation, PS-K, isolated from Coriolus versicolor was evaluated for its ability to enhance resistance against Edwardsiella tarda, causal agent of classical edwardsiellosis in tilapia, Oreochromis niloticus. Fish treated with a dose rate of 0.1 mg PS-K $g^{-1}$ body weight were challenged by intraperitoneal injection of E. tarda with different concentrations. Against low burdens of injections($1.2{\times}10^7$ and $1.2{\times}10^8$ cfu/fish), PS-K treated fish did not show any mortality compared to 50% and 100% mortality of control groups, respectively. However there was no increase of resistance against challenge with high concentrations of E. tarda ($1.2{\times}10^9$ and $1.2{\times}10^{10}$cfu /fish) except few days delaying of death. Tilapia injected with PS-K one day after intraperitoneal inoculation of E tarda($1.2{\times}10^7$ cfu/fish) showed 100% survival rate compared to control group of 50% survival rate. The result indicates the potential of PS-K as a prophylactic agent in aquaculture. The increased antibody response in fish received PS-K one week prior to FKC administration suggested the influence of PS-K on the specific humoral immunity and increased resistance against bacterial infection.

• Journal of fish pathology
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• v.22 no.1
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• pp.67-73
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• 2009

It was examined whether the common belief that "cultured puffer fishes do not contain tetrodotoxin (TTX)", the major lethal substance that accidently causes death in consumers of those fishes, is true in river puffer fish Takifugu obscurus. In mouse bioassay, lethal levels of toxins were detected in the ranks: gonad>liver>intestine>muscle>skin in wild puffer fish. In contrast, no mortality occurred in the mouse bioassay on cultured fish. However, there were sleepiness, sluggish behavior, and hind limb paralysis with the tissue extracts of cultured fish suggesting the presence of TTX or other similarly acting toxins. An attempt to confirm the presence of TTX in cultured fish with high performance liquid chromatography (HPLC) was not very successful. The results suggest possible existence of TTX toxins or similarly acting toxins.

• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.486-492
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• 2013

Recently, a new disease showing symptoms such as epidermal exfoliation and muscular necrosis occurred in cultured Korean catfish. Although the mortality of fishes was low but the economic damages owing to loss of commercial value were severe. The authors isolated the causative agent from diseased fish and observed pathological changes both in naturally and artificially infected fish. The causative bacteria was identified as Aeromonas veronii. Subsequently we observed the daily death and pathological symptoms of artificially infected fish with Aeromonas veronii. Symptoms of artificially infected fish were similar to those of naturally infected fish and all fish died within 7 days after infection. Histopathological changes on the naturally infected fish revealed severe congestion and necrotic degeneration in the liver, spleen and kidney. Some bacterial aggregates with inflammatory degeneration were observed in the heart, and congestion and fibrosis in the lamina propria of digestive tube were predominant. In artificially infected fish, skin erosion and necrotic degeneration of muscle tissue around injected region were particularly manifested. Degeneration of hepatocytes in liver and hyalic degeneration around ellipsoids in spleen were partially observed. However, there were no predominant signs in digestive tube in artificially infected fish.

• Korean Journal of Ichthyology
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• v.28 no.1
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• pp.1-8
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• 2016

This study was conducted to investigate the physiological responses of sevenband grouper, Epinephelus septemfasciatus at low temperature condition in winter season. Water temperature was dropped from $12^{\circ}C$ to $5^{\circ}C$ by two different interval (interval I: $-1^{\circ}C/24h$ and interval II: $-1^{\circ}C/8h$). The experimental fishes were exposed for 9 days at each water temperature condition, and were observed survival rate. The blood sample was collected from fishes for analysis of cortisol, glucose, total protein (TP), and electrolytes ($Na^+$, $Cl^-$, $K^+$). Mortality of fish was not observed until $5^{\circ}C$. The mortality (12 individuals) began after 170 h and all fish were death after 174 h in interval I case, whereas the mortality (9 individuals) began after 72 h and all fish were death after 76 h in interval II case. Little different was observed in the physiological responses, but trend was similar between two intervals. The physiological metabolism of plasma cortisol and glucose were increased rapidly, and swimming ability and respiration response was faster at $7^{\circ}C$. This result means that the critical temperature of sevenband grouper was $7^{\circ}C$ at low water temperature condition.

• Nutrition Research and Practice
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• v.11 no.6
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• pp.492-499
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• 2017

BACKGROUND/OBJECTIVES: This study aimed to investigate the association of dietary patterns with overweight risk and all-cause mortality in pediatric cancer patients. SUBJECTS/METHODS: Prospective cohort study was undertaken; 83 cancer patients admitted to the pediatric cancer ward at a university hospital in Seoul were included and followed for obesity and death over 24 months. Food consumption data were collected from patients using validated meal order sheets for breakfast, lunch, and dinner at the pediatric cancer ward over 3 days. Using principal component analysis, three dietary patterns were derived from 29 food groups. RESULTS: Eighteen deaths occurred among the patient cohort during the follow-up period. The "spicy & fried meat and fish" dietary pattern was positively associated with overweight risk at both baseline [odds ratio (OR) = 4.396, 95% confidence interval (CI) = 1.111-17.385, P for trend = 0.023] and after 6 months (OR = 4.088, 95% CI = 1.122-14.896, P for trend = 0.025) as well as all-cause mortality (hazard ratios = 5.124, 95% CI = 1.080-24.320, P for trend = 0.042), when comparing the highest and lowest tertiles after adjusting for covariates. The "fish, egg, meat, and fruits & vegetables" dietary pattern was associated with lower overweight risk after 24 months (OR = 0.157, 95% CI = 0.046-0.982, P for trend = 0.084). CONCLUSION: The results imply that dietary patterns might be associated with weight gain and premature death among pediatric cancer patients.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.75-90
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• 2003

When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

• Journal of Microbiology
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• v.40 no.4
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• pp.295-300
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• 2002

Previously, we reported induced expression of developmentally regulated CTP-binding protein 2 (DRG2) in fish cells at the late stage of rhabdovirus infection. To investigate the biological role of fish DRG2 (fDRG2), we transfected CHSE-214 cells with an expression vector containing complete fDRG2 fused to the N-terminal end of an enhanced green fluorescent protein (EGFP). Low level expression of fDRG2-EGFP did not induce morphological change or cell death. However, a high level expression of fDRG2-EGFP induced cell rounding and caused depletion of the cell population in FACS analysis. Several truncated fragments were fused to EGFP. FACS analysis was conducted to determine the presence of cells expressing high levels of the resulting chimera. While cells expressing a high level of N-terminus were detected, those expressing high levels of the C-terminal fragment 243-290 containing the G4 motif were absent in FACS analysis. Based on these observations, we propose that overexpression of fDRG2 may induce cell rounding, a representative cytopathic effect of virus-infected cells in the late stage of infection and the C-terminus of the fDRG2 is essential for this function.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.41-48
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• 2017

Encircling gill net fishery is a kind of gill net which is generally used in shallow coastal waters. After the fish have been encircled by the gill net, noise stimulus such as a stone or sound is used to force them to gill or entangle themselves in the netting surrounding them. Although the fishing by a stone is a traditional fishing method, it is considered as an illegal fishing method by physical stimulus such as explosives and mechanical vibrator. However, this illegal fishing method has raised some problems to the fishing boat of other fisheries or many anglers due to disturb aggregating fish schools. This study is aimed to provide scientific base data to verify whether to impact the ecosystem caused by this encircling gill net. This study exhibited that the impulse noise by concrete sphere in the encircling gill net was $159dB/{\mu}Pa$, the ambient noise from ship engine was $160dB/{\mu}Pa$, and the maximum noise from continuous artificial vibrator was $175dB/{\mu}Pa$. These may be stimulus to the escape of fish distributed in a wide area in its natural state; it is not likely the cause of death due to catastrophic stress. Therefore, it needs to prepare the consideration of standard limit on fishing stimulus in fishing methods of the fishery laws and regulations, prevent fishermen form using illegal fishing gear (i.e. explosive sound standards: $200{\sim}220dB/{\mu}Pa$ and provide them with countermeasures.

• Journal of fish pathology
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• v.22 no.3
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• pp.193-200
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• 2009

This study was performed to natural infection of Ichthyophthirius multifiliis and mortalities of two fish species were compared at 10${^{\circ}C}$ and 17${^{\circ}C}$ after artificial infection with the parasite. Subsequently compared to motality by the artificial infection with the different parasite orgin of host at 17${^{\circ}C}$ using rainbow trout Oncorhynchus mykiss. The prevalence of Ichthyophthirius multifiliis in cherry salmon was higher than that in rainbow trout during the periods of low temperature but no difference in high temperature season. The parasite was not detectable in culturing water and detritus except May that of density has been high. Susceptibility to the parasite was higher in cherry salmon than in rainbow trout at 10${^{\circ}C}$ of water temperature but no difference between two fish species at 17${^{\circ}C}$. When rainbow trout were infected with Ichthyophthirius multifiliis from rainbow trout and cherry salmon at 17${^{\circ}C}$, there was no difference in death of host. These results suggest that cherry salmon have higher susceptibility to Ichthyophthirius multifiliis than rainbow trout at low temperature.

• Journal of fish pathology
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• v.17 no.2
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• pp.83-90
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• 2004

The outbreak of haemorrhagic specticemia and lesions in dermis, frequently associated with keratitis have occured on rock sea bream (Oplegnathus fasciatus) reared in Jeju island. A bacterium isolated from the diseased fish identified as Pseudomonas sp. by morphologic, cultural, and biochemical tests. The bacterium was identified Pseudomonas anguilliseptica according to 16S rDNA sequence analysis. The highest growth rate of this strain was obtained at 20 to $\25^circ{C}$ although the disease occurred mostly below $16^\circ{C}$. The challenge test by ip injection revealed that this bacterium was pathogenic to rock sea bream. All experimental fish in challenged by ip injection died within 21 days but there was no death in control group. The bacterium was sensitive to Doxycycline, Chloramphenicol, Ciprofloxacin, Erythromycin, Flumequine, Nalidixic acid, Norfloxacin, and Ofloxacin.