• Journal of Fisheries and Marine Sciences Education
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• v.28 no.3
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• pp.692-700
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• 2016

This study was aimed at investigating the residual patterns of thiamphenicol (TP) in the cultured olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes schlegeli) following oral administration. TP concentration were detected by high performance liquid chromatography with UV detector. The recovery rates of TP in serums ranged 77.05~97.23% (olive flounder) and 89.96~97.11% (black rockfish) for the concentration of 0.1, 1.0, $10{\mu}g/mL$, respectively. After single administration of TP (100 mg/kg body weight) by oral route in olive flounder ($700{\pm}50g$, $23{\pm}1.5^{\circ}C$) and black rockfish ($500{\pm}30g$, $23{\pm}1.5^{\circ}C$), the concentration in the serum was determined at 1, 5, 10, 15, 24, 30, 50, 168, 264 and 432 h post-dose. Two-compartment model was applied to analyze in the pharmacokinetics of TP administered to the fishes. In the serum of olive flounder, TP was detected on 10 and 15 hours after treatment were $10.08{\mu}g/mL$ and $10.06{\mu}g/mL$ as maximum level, respectively. In the serum of black rockfish, TP was detected on 15 hours after treatment were $8.88{\mu}g/mL$ as maximum level. Concentrations of TP to the fishes were not measurable at 432 hours (18 days) after treatment in all samples. Similar residual patterns of TP were revealed between the fishes. These results are helpful for estimating withdrawal time of TP which has been already in use for farmed fish treatment.

• Journal of Aquaculture
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• v.19 no.2
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• pp.140-146
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• 2006

This study was conducted to investigate the effect of dietary oxidized oil and ${\alpha}$-tocopherol level on growth and body composition of juvenile flounder. To prepare oxidized diets, squid liver oil was oxidized by aeration at $25^{\circ}C$ for 30 days. The six diets were prepared to contain 6% fresh or oxidized squid liver oil as the lipid sources in combination with three levels of ${\alpha}$-tocopheryl acetate at 0, 80 and 800 mg/kg diet. Triplicate groups of fish ($3.9{\pm}0.1$) were fed to apparent satiation twice a day for 8 weeks. Survival was not significantly different among treatments. Weight gain, feed efficiency, daily feed intake, protein efficiency ratio and condition factor of fish fed the fresh oil diets were significantly higher than those of fish fed the oxidized oil diets (P<0.05). The increase of the vitamin E level in diets did not result in any significant improvement on growth performance of fish fed both oil diets. The vitamin E content of the liver and dorsal muscle increased with increasing dietary vitamin E level at both oil diet groups. A decreasing trend in vitamin E content of the tissues was observed in fish fed the oxidized oil diets at the same dietary vitamin E level. Significantly higher moisture content and lower crude lipid content were observed in the whole body of fish fed the oxidized oil diets than fish fed the fresh oil diets (P<0.05). Dietary lipid source affected the fatty acid content of the whole body; higher contents of saturated and monoenoic fatty acids, and lower n-3 HUFA contents such as 20:5n-3 and 22:6n-3 were observed in fish fed the oxidized oil diets than those of fish fed fresh oil diets. The results of this study suggest that the dietary oxidized oil may impair the growth performance, and an increase in ${\alpha}$-tocopheryl acetate supplementation have no beneficial effect on growth and feed efficiency of juvenile flounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.1
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• pp.18-24
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• 2011

This study investigated the physicochemical and enzymatic properties of unmarketable cultured bastard halibut (Paralichthys olivaceus) of different weights as a potential source of surimi and surimi gel. The proximate composition of cultured bastard halibut of different weights did not differ significantly at P<0.05 (light weight (LBH) 400~500 g, medium weight (MBH) 600~800 g, and heavy weight (HBH) > 1,000 g). Compared to Alaska pollock muscle, the bastard halibut muscle had a 4% higher crude protein content and 6% lower moisture content. The collagen content of LBH bastard halibut muscle was 1.58 g/100 g, which was lower than or no different from bastard halibut weighing different amounts. Regardless of fish weight or pH, the enzymatic activities of crude fish extracts ranged from 0.34~0.48 U/mg for casein and hemoglobin, 11.0~12.7 U/mg for LeuPNA, 5.4~6.1 U/mg for ArgPNA, 2.3~2.9 U/mg for SAAPFNA, and 0.1~0.2 U/mg for BAPNA. The yield of surimi gel from LBH was 24.4%, which was similar to that from MBH and lower than that from HBH. The surimi gel from LBH was similar to that from HBH, while weaker than that from MBH. The surimi gel from LBH gel was stronger than grade SA gel from commercial Alaska pollock.

• 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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1192-1201
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• 2016

This study was conducted to investigate sensory characteristics and consumer acceptance of sliced raw fish. The two most popular varieties in Korea, flounder and rockfish, were used. Samples of each variety were prepared as follows to create consistent perceptible sensory differences: 'fresh' (consumed within 2 h after sacrifice), 'aged' (stored at $1^{\circ}C$ for 24 h), 'frozen' (frozen at $-16^{\circ}C$ for 23 h then thawed at $23.5^{\circ}C$for 1 h), and 'immersed' (immersed in sterilized water at $1^{\circ}C$ for 24 h). Sensory profiles of samples were determined through quantitative descriptive analysis using 10 trained panelists. Consumer acceptance test was conducted using 47 consumers. Analyses of variance were conducted to test significance of differences in sensory profiles and hedonic ratings among samples. Consumers were clustered according to their overall liking scores, and their preference patterns were cross-checked with sensory profiles. For both fish varieties, 'fresh' was characterized by stronger hardness, cohesiveness, springiness, cartilage-like texture (applied to only rockfish), and fishy flavor, whereas 'frozen' and 'immersed' were distinguished from other samples for their stronger wetness, juiciness, and fresh fish flavor than those of other samples. 'Aged' was significantly less hard, cohesive, and springy than 'fresh' as well as less juicy and wet than 'frozen' and 'immersed'. Consumers significantly preferred 'fresh' flounder and rockfish to others for their strong cohesiveness and springiness, indicating textural attributes were main factors affecting consumer preferences. However, for both flounder and rockfish, 40~50% of respondents preferred 'frozen' and 'immersed' to 'fresh' for their tenderness and fresh fish flavor. For this group of consumers, flavor liking had a greater effect on overall preference than texture preference. The result suggests that cohesive and springy textures and fresh fish flavor are major drivers of preferences for raw fish slices, but their relative importance and optimal levels varied across individual consumers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.598-605
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• 2010

This study investigated the physicochemical and enzymatic properties of unmarketable bastard halibut (Paralichthys olivaceus) cultured in different regions (i.e., Jeju, Wando, and Geoje) as a potential source of surimi and surimi gel. The proximate composition of unmarketable bastard halibut cultured in different regions did not differ significantly at P<0.05. Compared to Alaska pollock muscle, all of the unmarketable bastard halibut muscle had a 4% higher crude protein content and 5% lower moisture content. The collagen content of bastard halibut muscle cultured in Jeju was 1.96 g/100 g, which was higher than in fish cultured in other regions. Regardless of the region where cultured or pH, the enzymatic activities of the crude extracts from unmarketable bastard halibut muscle ranged from 0.30.0.48 U/mg for casein and hemoglobin, 11.9.13.7 U/mg for LeuPNA, 5.6.6.7 U/mg for ArgPNA, 2.8.4.7 U/mg for SAAPFNA, and 0.1.0.2 U/mg for BAPNA. Regardless of region, no mercury or lead was found in any of the unmarketable bastard halibut muscle, except for lead in fish cultured in Geoje. The strength of surimi gels from unmarketable bastard halibut cultured in Jeju, Geoje, and Wando was 1059, 988, and 900 g${\times}$cm, respectively. The surimi gel from unmarketable bastard halibut cultured in Jeju was stronger than commercial Alaska pollock surimi, which was grade SA.

• Journal of Environmental Impact Assessment
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• v.27 no.1
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• pp.17-32
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• 2018

The need for seawater desalination is increasing in terms of securing various water resources, but few studies are available as for the environmental impact of hypersaline concentrated water (brine) discharged from desalination plants. Domestic studies are concentrated mainly on toxicity evaluation that phytoplankton, zooplankton larvae and green algae (Ulva pertusa) are negatively affected by concentrated water. The mortality of Paralichthys olivaceus showed a linear relationship with increasing salinity, and Oryzias latipes died 100% at concentrations above 60 psu. Foreign studies included monitoring cases as well as toxicity evaluations. The number of species decreased around the area where the concentrated water discharged. The hypersaline concentrated water affects the pelagic and benthic organisms. However, the fishes escaped when exposed to salinity, and the pelagic and benthic organisms resistant to salinity survived the hypersaline environment. The salinity limit and distance from the outlet was presented as the regulatory standard for bine discharge. There were differences in regulatory standards among country and seawater desalination plants, and these regulatory standards have been strengthened recently. In particular, California Water Boards were revised to ensure that the maximum daily salinity concentration does not exceed 2 psu above the ambient salinity level within 100 m of the outlet.

• Journal of fish pathology
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• v.27 no.2
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• pp.107-114
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• 2014

For the treatments and protection of bacterial fish disease, many requirements are needed for aquatic probiotics so that they are effective in aquaculture animals but are also harmless to humans. In the present study, among 17 candidate probiotic bacteria (CPB) obtained from the edible part of the shellfish, Bacillus sp. CPB-St (CPB-St) were selected and in vitro evaluated for the possibility as a probiotic strain for the control of fish streptococcosis which frequently occurs in the olive flounder farms. CPB-St showed inhibitory effects on the growth of various fish pathogenic bacteria, Streptococcus sp., S. parauberis, S. iniae, Lactococcus garvieae and L. piscium by the double layer test ranging about 18~26 mm of clear zone. Inhibitory activity of CPB-St to Streptococcus sp. was observed 6 hours after and the growth of Streptococcus sp. was decreased to 8~55 folds in the co-culture of CPB-St with Streptococcus sp.. The safety of CPB-St to fish and survival of CPB-St in the intestine were assessed in the olive flounder, Paralichthys olivaceus. Fish mortality was not observed in artificial infection with CPB-St for 2 weeks. CPB-St was entirely excreted from the stomach and intestine 24 hours after oral injection. This results indicate that CPB-St has potential applications as a probiotic for the control of fish streptococcosis in aquaculture.

• Journal of fish pathology
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• v.13 no.1
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• pp.37-44
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• 2000

CT(Sodium N-chloro-para toluenesulfonamide, Chloramine-T) known to be a strong oxidative agent was investigated to use as a candidate of disinfectant in the marine aquaculture industry by the analysis of the bactericidal activity against different aquatic microorganisms. One hundred percent mortality appeared at and above 16 ppm CT in sea water in flounder, the predominant species in the marine aquaculture of Korea, when exposed for 48hr. However, bactericidal activity was appeared to be very effective, and all different species of the fish pathogenic bacteria exposed to CT of less than 2 ppm in sea water were dead within 15 min. It allowed us to confirm that CT could be a very effective disinfectant to protect the spread of fish pathogenic bacteria derived from diseased fish or sea water in marine aquaculture. High concentration(10 ppm) with longer exposing time(24 hrs) was required for the algicidal activity of CT, at which concentration might induce the acute toxicity against fish, however, restricted the expanded use of CT for the elimination of zooplanktons at phytoplanktons in marine farms. Moreover the bactericidal activity of CT inhibited almost completely in the present of more than 10 ppm of organic materials pointed out that quality of the culturing sea water should be considered carefully for the application CT to the aquatic farms as a therapeutic agent.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.313-318
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• 2016

Bacteria in the viable but nonculturable (VBNC) state fail to produce colonies on routine bacteriological media, but are still alive in the state of very low metabolic activity. The aim of the present study was to induce the VBNC state of the Edwardsiella tarda using sea water microcosm under starvation conditions at $10^{\circ}C$ and to investigate resuscitation of the VBNC cells in temperatures changed from 10 to $25^{\circ}C$, with and without additives. E. tarda entered into the VBNC state within about 42-84 days of incubation in the microcosm. Throughout this period, the total cell counts as determined using acridine orange direct counting remained near the original inoculum level of ${\sim}10^8cells/ml$. The live cell counts measured with direct viable counting, on the other hands, declined to ${\sim}10^4cells/ml$. When the VBNC cells were incubated with addition of yeast extract, fish muscle extract or serum at $25^{\circ}C$, the ratios of resuscitated samples were 37%, 23%, and 37%, respectively. The characteristics of resuscitated E. tarda were consistent with those of the original E. tarda. When the resuscitated E. tarda were intraperitoneally injected into olive flounders, all fishes died within 5 days, indicating that the VBNC E. tarda might retain its pathogenic potential. Therefore, E. tarda under starvation conditions in the winter enter into the VBNC state and the VBNC E. tarda cells resuscitated at summer and autumn seawater temperature are considered to be pathogen continuously to olive flounder on the southern coast of Korea.