• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.93-93
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.2
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• pp.125-130
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• 2010

A trimethoprim resistant Vibrio parahaemolyticus, which cause acute gastroenteritis in humans, was isolated from farmed fish and seawater. The resistance profiles of isolated V. parahaemolyticus and their correlation with mobile elements were investigated. All of the V. parahaemolyticus were resistance to both rifampin and trimethoprim. The presence of class I integron was confirmed by PCR. PCR-amplified inserted gene cassettes contained aminoglycoside aac6-II, rifampin arr-3 and trimethoprim dfrA27 resistance genes. This study indicated that class I integron mainly contributed to the circulation of trimethoprim resistance determinants in V. parahaemolyticus.

• Proceedings of the Korean Aquaculture Society Conference
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• 2005.05a
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• pp.130-130
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.481-486
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• 2009

In 2007, 43.5% mortality of the cultured oyster population occurred in Gamak Bay. Mortality rapidly increase in September and peak in October. To prevent future mass-mortality event, we investigated spawning and variation of oyster body composition. The main spawning period of culture oyster occurred from August to September. Condition index and body composition (protein and glycogen) appeared to be influenced by the spawning activity. Condition index and glycogen content in September were lowest (13.5% and 5.6 mg/g, respectively). However, protein, lipid and glycogen contents did not rapidly recover after the spawning activity. The data indicates that mass-mortality of cultured oysters in Gamak Bay may be due to deteriorated health, spawning activity, stress of the high water temperature and decreasing food resources.

• Journal of fish pathology
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• v.26 no.1
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• pp.45-50
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• 2013

Enrofloxacin is one of the normally used flouroquinolones in mammalian and fish but its withdrawal time and studies were remain obscure. The residual contents of enrofloxacin in fish muscle were analyzed by using HPLC-FLD. More than 0.1 mg/kg of ENR was detected in muscle tissues and the residues were found over 1 year after treatment. The concentration of ENR in Paralichthys olivaceus was not affected by water temperature and lasted for an extended amount of time. The spike recoveries of ENR in the muscle tissue ranged from 78% to 85%. From this results, we need the prescription by veterinarian or aquatic organism disease inspector in ENR usage to assure safety of fish. Future research is required to determine the recommendation dose of ENR for side effects and safety.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.159-159
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• 2009

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.161-161
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• 2009

• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.229-234
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• 2011

In order to assess changes in the activity of immunecompetency present in Crassostrea gigas infected with Marteilioides chungmuensis (Protozoa), the total hemocyte counts (THC), hemocyte populations, hemocyte viability, and phagocytosis rate were measured in oysters using flow cytometry. THC were increased significantly in oysters infected with M. chungmuensis relative to the healthy appearing oysters (HAO) (P<0.05). Among the total hemocyte composition, granulocyte levels were significantly increased in infected oysters as compared with HAO (P<0.05). In addition, the hyalinocyte was reduced significantly (P<0.05). The hemocyte viability did not differ between infected oysters and HAO. However, the phagocytosis rate was significantly higher in infected oysters relative to HAO (P<0.05). The measurement of alterations in the activity of immunecompetency in oysters, which was conducted via flow cytometry in this study, might be a useful biomarker of the defense system for evaluating the effects of ovarian parasites of C. gigas.

• Development and Reproduction
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• v.18 no.1
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• pp.13-23
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• 2014

This study is conducted to monitor the morphological developmental features of the egg development, larvae and juvenile of Epinephelus septemfasciatus, the fertilized eggs were gotton using artificial insemination. Matured parents are collected from marine caged fish farms in Geomun-ri, Samsan-myeon, Yeosu-si, Jeollanamdo Korea in June 2012. The fertilized eggs were pelagic eggs containing one oil globule, and measured 0.81~0.89 mm ($0.85{\pm}0.04mm$, n=50) in diameter. In regard to rearing environment, the water temperature is $21.0{\sim}23.0^{\circ}C$ and the salinity is 32.0~33.2‰. Hatching was observed from 48 hours after fertilization, the mouth and anus of prelarvae was not opened but had egg yolk at newly hatched. 4 days after hatching, the mouth and anus of postlarvae was opened and began to eat Rotifer and was measured 2.40~2.49 mm ($2.45{\pm}0.03mm$ n=10) in total length. 12 days after hatching, postlarvae was measured 3.77~4.67 mm ($4.27{\pm}0.33mm$) in total length, its the second pole tide of dorsal fin and the first pole tide of pelvic fin was extended longitudinally. 71 days after hatching, juvenile was measured 40.5~45.4 mm ($42.6{\pm}2.04mm$) in total length. Seven bands were observed in body, and pole tides of dorsal and pelvic fins were shortened.

• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.103-111
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• 2012

Intestinal giant-cystic disease (IGCD) of the Israel carp (Cyprinus carpio nudus) has been recognized as one of the most serious diseases afflicting inland farmed fish in the Republic of Korea, and Thelohanellus kitauei has been identified as the causative agent of the disease. Until now, studies concerning IGCD caused by T. kitauei in the Israel carp have been limited to morphological and histopathological examinations. However, these types of diagnostic examinations are relatively time-consuming, and the infection frequently cannot be detected in its early stages. In this study, we cloned the full-length 18S rRNA gene of T. kitauei isolated from diseased Israel carps, and carried out molecular identification by comparing the sequence with those of other myxosporeans. Moreover, conventional PCR and real-time quantitative PCR (qPCR) using oligonucleotide primers for the amplification of 18S rRNA gene fragment were established for further use as methods for rapid diagnosis of IGCD. Our results demonstrated that both the conventional PCR and real-time quantitative PCR systems applied herein are effective for rapid detection of T. kitauei spores in fish tissues and environmental water.