• Journal of fish pathology
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• v.2 no.1
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• pp.19-30
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• 1989

The purpose of this study was to obtain the fundamental data for health assessment of cultured fishes. A series of hematological studies and blood chemistries were made on cultured israeli carps from May, 1988 to May, 1989. The results of this study were as followings : 1. The blood constituents of healthy carps were Hct $32{\pm}3.4%$, Hb $8.3{\pm}0.9g/l$, RBCs $132{\pm}27.6({\times}10^4cm^3)$), Total protein $2.7{\pm}0.7g/dl$, GOT $143{\pm}19.5U$, GPT $50{\pm}14.2U$, Total glucose $70{\pm}12.6mg/dl$ and BUN $7.5{\pm}1.9mg/dl$, etc. 2. The blood constituents by change of water temperature with the control of $23^{\circ}C$ showed the decrease in Hct and RBCs at $18^{\circ}C$, and the increase in Hct, RBCs and glucose at $28^{\circ}C$. 3. The blood constituents by change of dissolved oxigen with the control of 4.5ppm showed the increase in Hct and RBCs at 3ppm, and the decrease in Hct and RBCs at 7ppm. 4. In the case of intramuscular injection of Streptococcus sp. with $10^6cells$/fish infection dose, there showed marked decrease in Hct, RBCs, glucose and BUN with inflammatory reaction, and the fishes were recovered in 16 days. 5. In the case on intraperitoneal injection of Streptococcus sp. with $10^4cells$/fish infection dose, there showed decrease in Hct, RBCs and BUN with inflammatory reaction, but there were no dead cases. 6. In the case of intramuscular injection of Edwardsilla tarda with $1.2{\times}10^8cells$/fish infection dose, there showed decrease in Hct and RBCs, and increase in TCHO, GOT, GPT and BUN with marked inflammatory reaction, and 60% of inoculated fishes were died within 3 or 4 days.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.1
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• pp.40-46
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• 2020

In this study, we examined the quality of fish cakes prepared using the flour obtained from the following different rice varieties: Baekogchal, Dodamssal, Hangaru, Jeogjinju 2, Josaengheugchal, Saeminyeon, Saeilmi, and Shingil. The moisture content of the fish paste containing rice flour ranged from 67.40% to 69.90%, and was highest in the paste prepared using Baekogchal flour. The lipid and protein contents of the paste ranged from 0.05% to 0.43% and 11.36% to 11.69%, respectively, whereas the carbohydrate content was between 10.36% and 12.32%, and was highest in the paste prepared using Jeogjinju 2 flour. Fish cakes prepared using the flour from Baekogchal, Jeogjinju 2, and Josaengheugchal rice were found to have the hardest consistency. Sensory evaluations indicated that fish cakes prepared using Shingil flour had the best texture. Furthermore, the total polyphenol content was significantly higher in the fish cakes prepared using Josaengheugchal flour (165.12 mg GAE/100 g), whereas the DPPH and ABTS radical scavenging activities were significantly higher in the fish cakes prepared using Josaengheugchal flour (39.37 and 175.37 mg TE/100 g, respectively). In conclusion, we confirmed that the quality of fish cakes is affected by the characteristics of the flours obtained from different rice varieties. Among the varieties assessed, the quality of Shingil and Josaengheugchal varieties was suitable for preparing rice-containing fish cakes.

• Journal of Aquaculture
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• v.16 no.3
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• pp.190-195
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• 2003

Dietary optimum ratio of frozen raw fish and commercial compound meal (CCM) in moist pellet (MP) were investigated to improve the growth rate, and feed and economical efficiency in the flounder, Paralichthys olivaceus. Experimental fish (average body weight, about 48 g) were divided into 6 groups and each group was fed with raw fish (FRF), and MPs (ratio of raw fish and CCM=9:1, 8:2, 7:3, 6:4 and 5:5) for 10 weeks. The 9:1, 8:2, 7:3, 6:4, 5:5 groups showed no significant difference in weight gain as 203.5~217.3%, while the FRF group showed significantly low growth rate as 183.1%(P<0.05). The feed efficiency gradually increased with the increase in the ratio of CCM and was the highest in the 5:5 group as 89.7%. As a result of analysis of body composition after the experiment, moisture was significantly low in the 7:3 group (P<0.05) and crude protein was significantly low in the 9:1 group (P<0.05). The crude lipid increased as the ratio of raw fish increased, and it was the highest in the raw fish group (8.3%) and the lowest in the 5:5 group (4.6%). There were no significant difference in hepatosomatic index (HSI) and condition factor(CF) among the experimental groups. Visceralsomatic index (VSI) increased with the increase in the ratio of raw fish and was significantly high in the raw fish group as 5.49 (P<0.05). For the unit cost of feed, it was found that raw fish was economical when mackerel, a source of raw feed, was 400 won/kg, while the ratio of 5:5 was economical when it was more than 500 won/kg. Results of this study concluded that sole use of raw feed is not desirable in view of growth, environment and economy, and the 5:5 group showed highest effect under the least use of raw feed.

• Journal of fish pathology
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• v.35 no.1
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• pp.1-25
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• 2022

The aquaculture industry has developed rapidly over the last three decades and is an important industry that supplies over 15% of humans' animal protein intake; therefore, there is a need to increase production to meet the continuous demand. The fish cage farms on the southern coast (Kyengsangnam-do and Jeollanam-do) of Korea are critical resources in aquaculture because they account for approximately 90% of the national total fish cage farms by water area ratio. However, the current aquaculture environment is being gradually affected by climate change, which is a global issue, and its effects are expected to intensify in the future. Therefore, it is urgently imperative to accurately evaluate the effects of climate change on South Korean aquaculture industries and to develop social and national strategies to minimize damage to the fishing industry. The damage to fish farmed in cage farms on the southern coast is increasing annually and the leading causes are high and low water temperature and red tides, which are directly or indirectly related to climate change. At present, global warming can provide opportunities for aquaculture industrialization of fish or other novel species, with economic implications. However, despite such opportunities, the influx of new species can also cause problems such as ecological disturbances, increase in the reproduction frequency of microalgae such as red tide, increase in disease incidence, and occurrence and periods of high water temperatures in summer. The scale of farmed fish mortality is increasing due to the complex effects of these factors. Increased damages due to fish mortality not only have severe economic impacts on the aquaculture industry, but the social costs of responding to the damage and follow-up measures also increase. various active responses can reduce the mortality damage in fish farms such as improving the management skills in aquaculture, improved species breeding, efficient food management, disease prevention, proactive responses, and system-wide improvements. This review article analyzes the large-scale mortality cases occurring in fish cage farms on the southern coast of Korea and proposes measures to mitigate mortality and enhance responses to such scenarios.

• Journal of fish pathology
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• v.32 no.2
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• pp.59-67
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• 2019

We developed and subsequently characterized mouse antibodies (MAbs) against viral hemorrhagic septicemia virus (VHSV, genotype IVa), the causative agent of VHS. Five hybridoma clones secreting MAbs against VHSV were established. The MAbs recognized the glycoprotein (MAbs 2C10, 18H4, 23H6, and 30B7) and nucleocapsid protein (15E10) of VHSV by western blot analysis. All five MAbs reacted with VHSV-infected cells and tissue homogenates of VHSV-infected olive flounder (Paralichthys olivaceus) by western blot analysis. Whereas, no reactivity was observed in normal cells and tissue homogenates of normal olive flounder. Moreover, these MAbs reacted with VHSV, but did not react with other fish viruses (infectious hematopoietic necrosis virus, hirame rhabdovirus, spring viraemia of carp virus, infectious pancreatic necrosis virus, marine birnavirus, and nervous necrosis virus) by enzyme linked immunosorbent assay (ELISA). These results indicate that the MAbs are specific to VHSV and can be of value in VHSV detection.

• Journal of Aquaculture
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• v.18 no.4
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• pp.231-235
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• 2005

A 6-week feeding trial was conducted to determine optimum feeding frequency for growth of juvenile flounder Paralichthys. olivaceus during the summer season. Triplicate groups of fish (initial mean weight 3.7 g) were fed a extruded pellet with 5 feeding frequencies (one meal every 2 days, one meal a day, two meals a day, three meals a day and four meals a day) at $24.0\pm0.50^{\circ}C$ (mean$\pm$SD). Survival of fish fed one meal every 2 days was significantly (P<0.05) lower than that of the other groups. Weight gain, specific growth rate and daily feed intake increased with increasing feeding frequency (P<0.05). However, no significant differences were observed in weight gain, specific growth rate and daily feed intake of fish fed among two, three and four meals a day. feed efficiency and protein efficiency ratio were not affected by feeding frequency. Whole body contents of moisture, crude protein, crude lipid and ash were not significantly affected by feeding frequency. These results indicate that optimum feeding frequency is two meals a day for the optimum growth of juvenile flounder grown from 3.7 to 19.0 g under the experimental conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.138-146
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• 1989

This experiment was conducted to utilize the water soluble protein from the fish meal in wastewater as nitrogen source by alkaline protease producting bacteria and to investigate the culture condition of the production. G-12 and G-14 strains having the strong activity of the alkaline pretense were isolated from sea water. These strains were identified as Pseudomonas chlororaphis and Pseudomonas alcaligenes according to physiologycal characteristics, respectively. In enzyme production, galactose and casein for G-12 strain, and raffinose and the water soluble protein of the fish meal wastewater for G-14 strain was favorable as carbon and nitrogen source. An action of inhibition appeared in all of the metal salts used. The optimal temperature of enzyme production was $30^{\circ}C$ for all strains. Optimal initial pH for the enzyme formation in G-12 and G-14 strains was pH 10.0 and 8.0. When these two strains were incubated for $30\~35$ hours in the optimal production medium, the enzyme production reached at maximum.

• Korean Journal of Ichthyology
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• v.30 no.1
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• pp.1-8
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• 2018

We tried to determine the optimum salinity for a cultured of olive flounder (Paralichthys olivaceus) by investigating after exposing the fish at different salinity (10, 15, 20 and 25 psu) for 24 and 48 hours compared with control group (fish before transfer to experimental tank). As a control groups, we compared an analyzed with other experimental groups using olive flounder in natural sea water. Hematological parameters including hematocrit (Ht) and hemoglobin (Hb), cortisol and glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT), $NH_3$, osmolality, total protein (TP), $Na^+$, $K^+$ and $Cl^-$ mostly exhibited significant changes at 10 and 15 psu groups compared with control groups for 24 and 48 hours exposed. Plasma SOD (superoxide dismutase) and CAT (catalase) activity also increased with experimental groups (10 and 15 psu) compared to the control groups. The expression of HSP70 mRNA was also higher at low-salinity (10 and 15 psu) than at control group. In particular, after 24 hours exposed, it expression to 15 psu groups showed a significant difference compared to the control group. However, after 48 hours exposed, it expression was higher in the 10 psu groups than the control. It is assumed that the changes in the hematological responses and hormone, homeostasis and metabolism were resulted in to protect fish body from stress. Based on these results, we are expected that it will be used as basic data for the culture of olive flounder prepared for low salinity.

• Journal of Aquaculture
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• v.9 no.4
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• pp.353-361
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• 1996

The objective of this study was to investigate the essential fatty acids requirement and its optimal level in dietary for young of tiger puffer. The young puffer fish used in feeding trial were average body weight 3.45g. Fish were randomly divided into 11 groups containing 30 fish each in 200 ${\ell}$ tank and reared for 8 weeks at ambient temperature. In basal diets, defatted squid meal, casein-Na and activated gluten were used as the dietary protein source, dextrin and ${\alpha}$-starch (gelatinized starch) as the digestible carbohydrate source and beef tallow as the lipid source. Five fatty acids added to diet were linoleic acid (LNA), linolenic acid (LNA), eicosapentaenoic acid (EPA) ,docos-ahexaenoic acid (DHA) and n-3 HUFA. Among that, the supplement of LA and LNA were $1\%$ of total composition of diet, respectively, and EPA, DHA and n-3 HUFA ranged from $0.3\~1\%$ level. Growth and feed efficiency were measured to the interval of 2 weeks, and analyzed fatty acids composition of diet and liver by GCL. As a result of 8 weeks experiment, predominant growth were shown in $0.5\~1\%$ n-3 HUFA and $0.5\%$ DHA than others (P<0.05). In comparison of efficiency among EPA, DHA and n-3 HUFA groups, the most results were revealed in n-3 HUFA and the least in EPA. The adding effect was shown in EPA by increasing the fatty acids content from 0.5 to $1\%$ in diet. However, sudden decline and steady state in growth were observed in $1\%$ DHA and $1\%$ n-3 HUFA, respectively. The feeding efficiency and protein efficiency ratio were high in n-3 HUFA groups and $0.5\%$ DHA. Consequently, it is assumed that young puffer requires n-3 HUEA both EPA and DHA as essential fatty acids. The optimal content in diets are about $0.5\%$ of HUFA or DHA.

• Journal of Aquaculture
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• v.17 no.2
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• pp.109-114
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• 2004

The effects of different concentrations (0, 0.3, 0.6 and 0.9%) of fish feed additives (Hanbangchun and Olyukchun) utilizing effective microorganisms and herb medicine on activity of liver function were examined in olive flounder, Paralichthys olivaceus, Moreover, we investigated the characteristics of the additives. Total number of microorganisms (Lactic acid bacteria, Bacillus subtilis, Saccharomyces cerevisiae, Photosynthetic bacteria and Azotobactor) in the additives was 5.6${\times}$10$^{8}$ CFU/g in the Hanbangchun and 3.0${\times}$10$^{8}$ CFU/g in the Olyukchun. Levels of three typical pathological microorgamisms (Edwardsiella tarda, Vibrio anguillarum and Streptococcus sp.) in moist pellets (MP) were significantly decreased by the additives in a concentration-dependent way. Hepatosomatic index of fish in the 0.3% group was significantly increased. Total serum protein was increased in all the groups containing additives, but the protein content in liver was higher in the control group. Higher activities of catalase and superoxide dismutase which are involved in physiological defense mechanisms were found in the dietary groups containing 0.3% and 0.6%, respectively. These results suggest that the additives, Hanbangchun and Olyukchun, can increase tolerance of olive flounder against stress and hypoxic conditions by increasing activities of body antioxidant enzymes.