• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.2
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• pp.103-108
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• 2001

Toxic effect of TBTO on larva flounder was studied by the use of a food-chain system in which indirect toxicity from seawater or/and plankton can be measured, Under the treatment of 0.5 ng/L TBTO, the combined effect of diets ( Chlorella and rotifer) and seawater was significant by synergism, although the sole effect from TBTO treated diets or seawater was equally not, The values of $LT_{50}$ from results of acute-toxicity experiments for juvenile flounder were estimated to be 230.0, 48.0, 24.0, 14.6, 9.3 5.5 3.0 and 1.7 hr at 1, 10, 25, 50, 100, 250, 500 and 1000 ng/L of TBTO, respectively, and $96hr-LC_{50}$ was 3.5 ng/L. From the above results, the experiments for chronic toxicity of TBTO was executed at the concentration range of $1\sim10 ng/L$. In long-term experiments for four months, the weight and the total length of the juvenile flounder in all TBTO treated experiments slowly increased when compared to control. No significant differences in the growth and survival of the juvenile flounder were found in the treatment of 1 ng/L TBTO(P>0.05), But, $90\%$ of the juvenile flounder died in 20 days under TBTO treated seawater at both concentrations of 5 and 10 ng/L, The TBTO treated on seawater was more effective and significantly different in the growth and survival of the juvenile flounder when compare with that on artificial diets (P<0.05). From the all results, TBTO should be regulated below 5 ng/L in a coast.

• Journal of Life Science
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• v.18 no.6
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• pp.789-795
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• 2008

To study the possible use of probiotics in fish farming, we evaluated antagonism of antibacterial strain Bacillus amyloliquefaciens H41 against the fish pathogenic bacterium Vibrio anguillarum NCMB1. The purification of growth inhibition factor produced by B. amyloliquefaciens H41 was achieved by obtaining supernatant of this bacterium. The growth inhibition factor was purified to homogeneity by 70% ammonium sulfate precipitation, DEAE-sephadex A-50 ion exchange chromatography, sephadex G-200 gel filtration column chromatography, and sephadex G-50 gel filtration column chromatography with 40.8 fold of purification and 2.9% yield. The molecular weight of the purified growth inhibition factor was 48 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH and temperature for the growth inhibition factor were pH 7.5 and $30^{\circ}C$, respectively. The activity of growth inhibition factor was enhanced slightly by some metal ions, such as $Mg^{+2}$, $Mn^{+2}$, but was inhibited by the addition of $Co^{+2}$, $Hg^{+2}$, $Zn^{+2}$ and $Ag^{+2}$. NaCl stability of the growth inhibition factor was observed with 50% residual activity at 3% NaCl concentration. Toxicity test showed that the purified B. amyloliquefaciens H41 growth inhibition factor did not affect the live of Japanese flounder (Paralichthys olivaceus) and the effectiveness was 78% of residual lethality compared to commercial antibacterial agents.

• Journal of Aquaculture
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• v.19 no.3
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• pp.173-177
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• 2006

This study was conducted to evaluate extruded pellets (EP) for growth of adult flounder by comparing with raw fish-based moist pellet (MP). Two replicate groups of 150 fish per each tank (initial mean weight 329 g) were fed one of seven EP (EP1, EP2, EP3, EP4, EP5, EP6 and EP7) and a MP for 8 months. Survival of fish fed the MP was not significantly different from that of fish fed the EP1, EP5 and EP7, but significantly higher than that of fish fed the EP2, EP3, EP4 and EP6 (P<0.05). Weight gain of fish fed the MP was significantly lower than that of fish fed the EPI (P<0.05), but not significantly different from that of fish fed EP2, EP3, EP4, EP5, EP6 and EP7. Feed efficiency of fish fed the MP was significantly lower than EP1, EP3, EP4, EP5 and EP6 (P<0.05), but not significantly different from that of fish fed EP2 and EP7 Feed supply (kg/tank) of fish fed the MP was significantly higher than that of fish fed all EP (P<0.05). Condition factor of fish fed the MP was not significantly different from that of fish fed all EP. The contents of moisture, crude protein and lipid in dorsal muscle and whole body was not significantly different among the groups. It is concluded that the dietary formulation used in the EP1, EP3, TP4, EP5 and EP6 can be applied in the practical extruded pellet feeds for adult flounder (329-680g).

• Journal of Aquaculture
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• v.19 no.4
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• pp.225-230
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• 2006

A long-term (26 weeks) feeding experiment was conducted to examine the essentiality and requirement of inositol in diets for olive flounder because no information is available in the species. Five casein-gelatin based semi-purified diets were formulated to contain four different levels of myo-inositol (0, 0+antibiotic, 400, 800, and 1600 mg/kg, designated as M0, M0+, M400, M800, and M1600, respectively). One (M0+) of the control diets contained tetracycline hydrochloride (0.4%, wt/wt) as an antibiotic to inhibit biosynthesis of inositol by micro-organism in intestine of fish. Olive flounder at the early juvenile stage (initial body weight 1.22 g) were randomly distributed into fifteen 35 L tanks (48 fish/tank) and fed with one of the experimental diets (3 replicates per diet). At the end of the feeding trial, the weight gain, feed intake, specific growth rate, and protein efficiency ratio of fish fed diets containing higher levels of myo-inositol (M800 & M1600) were significantly higher than those of fish fed the other diets (P<0.05). Feed conversion ratio, survival, hematocrits, and hemoglobin of fish fed experimental diets were not significantly different among all the fish groups. Whole body compositions of fish were not different except for lipid content. The lipid content was significantly different between M0 and M400 diet groups. These results indicate that juvenile olive flounder requires dietary supplementation of myo-inositol in diets for normal growth and its optimum level seems to be approximately 800 mg myo-inositol/kg diet.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.5
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• pp.506-519
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• 2017

This study evaluated the protein recovery and functional properties and biological activity of boiled and steamed process water (BPW and SPW, respectively) generated from the preparation of concentrated roe of bastard halibut (BH; Paralichthys olivaceus), skipjack tuna (ST; Katsuwonus pelamis), and yellowfin tuna (YT; Thunnus albacares) using the cook-dry process. The protein loss from the water extracts (EXT) of 100 g of roe protein was 15.05-19.71% and was significantly (P<0.05) higher than that of BPW (5.47-10.34%) and SPW (3.88-8.18%). The foam capacity of BPW (166-203%) and SPW (15-194%) was better than that of EXT. The emulsifying activity index of the original samples was lower than those ($15.40-107.86m^2/g$) of diluted protein samples. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and the reducing power of BPW and SPW were stronger than those of EXT. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^+$) radical scavenging activity of EXT (0.028-0.045mg/mL) was significantly higher those of BPW and SPW. The angiotensin I-converting enzyme (ACE) inhibitory activity of SPW was the highest for BH (1.04 mg/mL), followed by YT and ST. The predominant amino acids in SPW were Glu, Ala, Leu, and His. These results demonstrate that processing water containing diluted organic components, including protein, can be consumed directly by humans as a functional reinforcing material after appropriate concentration processes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.412-418
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• 2001

The effects of dietary $\beta$-glucan administration on non-specific immune parameters in common carp, Cyprinus carpio, (1.0 g and 68.7 g of body weight) and flounder, Paralichthys olivcaces (12.1 g and 54.0 g of body weight) were evaluated. All fishes were fed an experimental diet supplemented with $\beta$-glucan at $0.1\%$ per kg diet for 5 weeks. A week intermission with basal diet occurred between first 2 weeks and second 2 weeks of $\beta$-glucan administration, The changes in the numbers of peripheral neutrophils and macrophages were counted under light microscopy and serum lysozyme activity was also analysed at a week of interval during the experiment. Phagocytic activities of leucocytes from the swimm bladder of carp and the peritonium of flounder were measured 5 weeks after feeding. The oral adminisration of $\beta$-glucan induced significant reduction in mortality after an artificial challenge with $1\times10^6$ cells of Aeromonas hydrophila in larger carp and $1\times10^5$ cells of Edwardsiella tarda in larger flounder but did not in other groups. The numbers of peripheral macrophages and neutrophils, phagocytic acitivies of leucocytes, and the activity of serum lysozyme were greatly increased in the fish fed a $\beta$-glucan supplemented diet. These suggest that $\beta$-glucan administration by oral route can enhance leucocyte phagocytic activity, serum lysozymal activity, and survival rate against artificial infections depending on the infected fish size and challenged bacterial concentration.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.694-706
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• 2017

This study evaluated the protein recovery, functional properties and biological activity of isolate processed water (IPW) generated in the preparation of protein isolates from fish roes (BH, bastard halibut Paralichthys olivaceus; ST, skipjack tuna Katsuwonus pelamis; YT, yellowfin tuna Thunnus albacares) by an isoelectric solubilization and precipitation process. The IPWs contained 2.7-5.4 mg/mL of protein, and the protein losses were 8-21% (P<0.05). The form capacity of IPW-3 for BH and ST, and IPW-4 for YT was 155, 194, and 164%, respectively. The emulsifying activity index ($27-43m^2/g$) of the YT-IPWs was the strongest, followed by ST ($7-29m^2/g$) and BH ($10-19m^2/g$). The 2,2-diphenyl-1-picrylhydrazyl scavenging activities of IPW-1 and -3 were higher than those of IPW-2 and -4. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid scavenging activity ($IC_{50}$, mg/mL) of IPW-2 and -4 was 0.03 mg/mL for BH, 0.04-0.08 mg/mL for ST, and 0.04-0.07 mg/mL for YT. BH IPW-3 had the strongest reducing power (0.41 mg/mL) and superoxide dismutase-like activity (1.68 mg/mL). The angiotensin-I converting enzyme inhibitory activity of IPW-3 was the highest for ST (1.52 mg/mL), followed by BH and YT. The common predominant amino acids in the IPWs were the essential amino acids Val, Leu, Lys, and Arg and the non-essential amino acids Ser, Glu, and Ala.

• Food Science and Preservation
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• v.18 no.5
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• pp.746-754
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• 2011

This study analyzed the taste components of dorsal muscle and fin muscle collected from olive flounder cultured with extruded pellet (EP) compared with those of olive flounder cultured with raw fish moist pellet (MP) as a control. The olive flounder in this study were cultured for 10 months with either the formulated extrude pellets (FEP), commercial extruded pellets (CEP) or the MP feed, and the average weight was 1.15 kg. The major nucleotides and related compounds in the dorsal muscles of the fish fed with MP, CEP and FEP diets were AMP and IMP. The fin muscle of the olive flounder contained the largest amounts of IMP($5.91{\mu}mol/g$). The K value of the dorsal muscle in olive flounder fed with MP, CEP and FEP showed 9.63%, 9.83% and 5.84%, respectively. The free amino acids in the dorsal muscle of olive flounder showed significantly differences in the composition depending on the feed, but the distribution of free amino acids showed similar patterns. Among free amino acids, taurine showed the highest content in all the experimental groups, and the asparagine and citrulline contents were significantly higher in the groups fed with CEP and FEP than in the group fed with MP. The significant differences were observed in the contents of specific free amino acids in dorsal muscle and fin flesh depending on the feed for cultured olive flounder.

• Journal of Veterinary Clinics
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• v.26 no.3
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• pp.226-230
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• 2009

We evaluated the efficacy of $\beta$-hemolytic Streptococcus(S.) iniae vaccine on cultured olive flounder. Three hundred flounders(weight $50{\pm}5$ g) were obtained from two farm at Wando and Taean in the southern and western coast of Korea at May and June 2007, respectively. Twenty of flounders moved in 0.5 tons aquaria in land-marine tank system of National Veterinary Research and Quarantine Service. Seawater was transported from the sea of Inchon in western Korea, and water temperature maintained to $22^{\circ}C$ and $25^{\circ}C$ during the vaccination and challenge test, respectively. We used the formalin-inactivated $\beta$-hemolytic S. iniae vaccine produced by domestic manufacturers. The vaccine was intraperitoneally administered to fish. The vaccinated and control group were challenged with intraperitoneal injection by virulent S. iniae SI-36 isolates with $5.0{\times}10^8$ CFU/fish at 3 weeks after vaccination. We evaluated the vaccine efficacy by calculating numbers of dead fish, and observing of clinical signs, exterior and gross lesions, and examining bacteria isolation and identification. Thirty-four(25.2%) of 135 control and vaccinated group fish were dead with serious anemia, abdominal extension, and hernia of intestine during 3 weeks post vaccination. We isolated Neoheterobothrium hirame from the buccal cavity and Edwardsiella tarda from kidney of dead and diseased fish. When infected fish with these agents were challenged with S. iniae SI-36 isolates, the cumulative mortality of control and vaccinated group were 86.7, and 46.7%, respectively. However, significant differences(p<0.05) were observed on cumulative mortality between control(20.0%) and vaccinated group(95.0%) at second trials with 40 healthy, and relative percent survival(RPS) was 78.0%. We confirmed that the efficacy of $\beta$-hemolytic S. iniae vaccine on olive flounder were impacted by health condition such as bacterial and parasitic diseases.

• Journal of Aquaculture
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• v.22 no.1
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• pp.1-4
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• 2009

A 10-week feeding trial was conducted to investigate the effects of feeding rate on growth and body composition of adult flounder during the summer season. Three replicated groups of the fish (initial mean weight of $535{\pm}4.1\;g$) were hand-fed a extruded diet twice a day at the different feeding rates of satiation (100%), 90%, 80% and 70% of satiation for 10 weeks. Mean Water temperature was $19.2{\pm}2.8^{\circ}C$ during the feeding trial. Weight gain and condition factor increased significantly with increase in daily feeding rate (P<0.05), but there was no significant difference in weight gain of fish fed the diet between 100% and 90% of satiation. Survival and feed efficiency were not significantly different among all groups. Proximate composition of dorsal muscle was not significantly affected by feeding rate. Based on the results of this study, optimum feeding rate for growth and condition factor of adult flounder (535-928 g) seemed to be 90% of satiation.