• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.964-967
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• 2008

Two structural protein genes, VP19 and VP466, of white spot syndrome virus (WSSV) were cloned and expressed in Sf21 insect cells using a baculovirus expression system for the development of injection and oral feeding vaccines against WSSV for shrimps. The cumulative mortalities of the shrimps vaccinated by the injection of rVP19 and rVP466 at 15 days after the challenge with WSSV were 50.2% and 51.8%, respectively. For the vaccination by oral feeding of rVP19 and rVP466, the cumulative mortalities were 49.2% and 89.2%, respectively. These results show that protection against WSSV can be generated in the shrimp, using the viral structural protein as a protein vaccine.

• Korean Journal of Veterinary Research
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• v.36 no.4
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• pp.1013-1016
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• 1996

Since 1993, sudden and massive death has occurred among penaeid shrimp, Penaeus orientalis cultured in Korea. We investigated the pathological characterizations on the spontaneously and experimentally infected penaeid shrimp. The major gross findings of the spontaneous cases were 2-6mm sized-white spots on the inside of the carapace and reddish discolorization. Histopathologically, massive necrosis of lymphoid organ, degeneration and necrosis of epithelia of epidermis and foregut were observed in both spontaneous and experimental cases. Amphophilic to basophilic intranuclear inclusion bodies were readly observed epithelia of epidermis, foregut and gills. Electron microscopy revealed enveloped, non-occuluded ellipsoid to rod shaped virus particles, within the nucleus, in the lymphoid organs and interstitial cells of hepatopancreas of both spontaneously and experimentally infected shrimps. The size of the virion was $375{\times}167nm$, and the nucleocapsid was $290{\times}75nm$. The causative agent causing massive death in penaeid shrimps in Korea resembles baculovirus associated with white spot syndrome (WSBV) occurred in Taiwan in virus morphology and gross and histological changes of the shrimps.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.216-223
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• 2001

The digestibility of organic matter (OM), crude protein (CP), ether extract and amino acids of a cassava root meal and rice bran diet, without (Basal) and with inclusion of fish meal (FM) or fresh (FSB) or ensiled (ESB) shrimp by-product in growing pigs (Large White$\times$Mong Cai) fitted with post-valve T-caecum (PVTC) cannulas was studied in a $4{\times}4$ change-over experiment. Significantly higher ileal digestibility of OM in the basal and FM diets and lower ileal digestibility of CP in the basal and ESB diets were found (p<0.05). Total tract digestibilities of OM and CP of diet ESB were lower (p<0.05) than in the other diets. The apparent ileal digestibilities of most amino acids were higher (p<0.05) in diets FM, FSB and ESB than in the basal diet. There was no difference (p>0.05) in the ileal digestibility of individual amino acids between diets FM, FSB and ESB, except for threonine, alanine and glycine. The estimated apparent ileal digestibility of individual amino acids in ensiled shrimp by-product was lower (p<0.05) than in fresh shrimp by-product and fish meal. In conclusion, as a result of the reduced daily intake of the diets containing shrimp by-products and lower ileal and total tract digestibility of both fresh and ensiled shrimp by-products complete replacement of fish meal cannot be recommended. The ensiled shrimp by-product was inferior nutritionally compared with fresh shrimp by-product. However, lower daily feed intakes of both the FSB and ESB diets suggest that the replacement should only be made partially, in order not to reduce the overall performance.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.461-467
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• 2017

Shrimps infected with WSSV(White Spot Syndrome Virus) generally exhibit white spots in their inner space of carapaces as an acute clinical sign. In an effort to identify the correlation between this acute clinical sign and the condition, the index factors (RNA/DNA concentration and ratio, trypsin activity) were analyzed. A total 580 farmed Fenneropenaeus chinensis and 130 Lithopenaeus vannamei were collected from western and southern fifteen outdoor ponds in Korea. The status of the white spot pathology was divided into four stages (stage 0, stage I, stage II, and stage III), in accordance with the clinical signs as to the size and area of white spots. A significant decrease in RNA concentration and RNA/DNA ratio for multi-infected fleshy prawn (WSSV and vibrio sp.) occurred during the stage III (the whole carapace is covered with a white spot). In particular, RNA/DNA ratio was significantly lower as $1.47{\pm}0.04$ than other groups. A similar trend was also found in the single infection (WSSV), but the decrease was less than the multi-infection. In the species comparison, both species were vulnerable to the multi-infection, but L. vannamei was more sensitive than F. chinensis(ANOVA, p<0.05): A significant decrease in RNA concentration and RNA/DNA ratio was first found in stage II for the former species, while it was found in stage III for the latter species. Trypsin activity was also showed a similar tendency with nucleic acid variation. Multi-infected shrimp showed drastically decrease of trypsin activity. According to the results, clinical signs of the white spot under carapace have an only physiological effect on shrimp if they covered entirely with white spots.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.521-523
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• 2001

White spot syndrome virus (WSSV) causes the most serious epizootic in cultured penaeid shrimp. The epizootic started in 1992, and spread through east and south east Asia and into other shrimp growing countries of the region. WSSV has also been reported from Penaeus chinensis cultured in Korean peninsula (Park et al., 1998; Kim et al., 1999). However, this paper deals with the WSSV infection in cultured and wild P. chinensis, purification and characterization of the pathogen, and the occurrence of other concomitant infection. (omitted)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.1
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• pp.133-139
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• 2023

The advantage of biofloc technology (BFT) in aquaculture is in the prevention of pathogenic transmission. In this study, we performed an investigation on viral, bacterial, and microsporidian parasite infections targeting a total of 194 whiteleg shrimp Litopenaeus vannamei reared in seven BFT-farms on the west coast of Korea in 2021. Hepatopancreatic and cuticular epithelium and pereiopods tissues of shrimp were tested for the four pathogens, Enterocytozoon hepatopenaei (EHP), Vibrio parahaemolyticus causing Acute Hepatopancreatic necrosis disease (VP_AHPND), white spot syndrome virus (WSSV), and hepatopancreatic parvovirus (HPV). The microsporidian parasite EHP was detected in the hepatopancreatic tissue of BFT whiteleg shrimp in the Ganghwa region, whereas no other pathogenic bacteria or virus was detected on the shrimp in the seven BFT-farms. As a result of bacterial flora in the rearing water of BFT whiteleg shrimp using DNA microbiome technology, V. chemaguriensis and V. alfacsensis were contained at 0.05% and 0.01%, respectively, but no VP_AHPND was detected. These findings will serve as a basis for supporting safe BFT-aquaculture of whiteleg shrimp.

• Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.367-379
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• 2023

The rapid expansion of shrimp production requires a huge amount of protein sources from soybeans and wild-caught fishmeal; both are becoming a shortage. Meanwhile, catfish production and processing is a giant industry in Vietnam, which produce hundred thousand tonnes of protein- and lipid-rich by-products, annually. Using catfish by-products to gradually replace the traditional protein sources in shrimp aquaculture may bring triple benefits: 1) reducing pressure on wild fish exploitation for fishmeal, 2) reducing the environmental impacts of catfish by-products, and 3) increasing the value and sustainability of aquaculture production. In this study, we used catfish by-products to produce fish protein hydrolysate (FPH) and nano-hydroxyapatite (HA) as additives in feed for Pacific white shrimp (Litopenaeus vannamei). The supplement mixture of FPH and HA was added into the commercial diet (Charoen Pokphand Group [CP], 38% protein, and 6.5% lipid) to reach 38%, 38.5%, 40%, 43%, and 44% of the crude protein content. The survival and growth of shrimps were weekly assessed to day 55. The results showed that the shrimp growth was highest at 43% crude protein content in the feed as indicated by an increase of 124% and 112% in shrimp weight and length, respectively, compared to the commercial reference diet. No negative effects of adding the mixture of FPH and HA on the water quality were observed. Vibrio density was lower than 6.5 × 10³ CFU/mL, which is the lowest Vibrio density negatively affecting the shrimp growth and development. These findings indicate that the mixture of FPH and HA are promising additive components in feed for post-larval shrimp L. vannamei diets.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.04a
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• pp.92-92
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• 2005

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.688-695
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• 2015

The objective of this study was to investigate the effects of bio-floc system that is composed of effective microorganisms (EM) on the microbial composition and water qualities in rearing water and the growth of Chinese white shrimp, Fenneropenaeus chinensis. To investigate the microbial composition according to the bio-floc levels, the study was conducted at 100 and 150% of bio-floc after 5 and 10 days in bio-floc system. The results showed that total bacteria count (TBC) and the counts of Latobacillus sp., Bacillus sp. and Rhodobactor sp., were significantly decreased after 5 days in bio-floc system. To assess the growth of F. chinensis according to the concentrations of bio-floc, the study was conducted at the bio-floc concentrations; 0 (control), 60, 80, 100, 120 and 140% of the prepared bio-floc for 90 days. The growth factors such as daily length and weight gain were considerably increased at the concentrations of bio-floc 100, 120, and 140% after 90 days. As water quality indicators, the values of total-N, NH₄⁺-N and PO₄^--P were analyzed, and they were significantly decreased at 120 and 140% of bio-floc, compared to the control. The results demonstrated that combination of EM showed the synergic effect on removing N and P.

• Journal of fish pathology
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• v.13 no.2
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• pp.97-102
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• 2000

In order to investigate the effect of chlorine disinfectant against white spot baculovirus (WSBV), 5, 10, or 30 ppm of sodium hypochlorite (NaOCl) was treated to the WSBV-infected shrimp, Penaeus chinensis. In contrast with the non-treated control, no shrimp was dead after of sodium hypochlorite treatment. This result indicated that WSBV was inactivated by chlorine treatment. No inactivation of WSBV was observed by 10, 20, 30 ppm of povidon-iodine treatment. WSBV was also inactivated by 2, 4 hr sunlight exposure and by 1, 2, 3 hr drying. WSBV was inactivated very effectively by addition of fresh water on sea water.