• Journal of Aquaculture
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• v.18 no.4
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• pp.287-292
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• 2005

An 8-week of growth feeding trial was conducted to evaluate effects of the experimental extruded pellet (EP), commercial EP and raw fish-based moist pellet (MP) for growing flounder (Paralichthys olivaceus). Three replicate groups of the fish average weighing 43.5 g were fed four experimental diets (EP1, EP2, EP3 and EP4), four commercial diets (EP5, EP6, EP7 and EP8) and MP. Weight gain of fish fed the EP2, EP3 and EP4 was the highest among treatments, but not significantly different to that of fish fed the EPl, EP7 and MP. Feed efficiency and protein efficiency ratio of fish fed the MP were the lowest among treatments, but daily feed intake and daily protein intake of fish fed the MP were the highest among treatments. Moisture, lipid and ash contents of whole body were affected by diets, but protein content was not affected by diets. It is concluded that the dietary formulations used in the EP2, EP3 and EP4 can be applied in the practical exuded pellet feeds for growing flounder of 42-108g size.

• Journal of fish pathology
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• v.4 no.2
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• pp.71-77
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• 1991

From August to October of 1991, a bacterial disease occurred in cultured flounder, of 0 age Paralichthys olivaceus, in Cheju-do. Typical symptoms of the diseased fish were the hemorrage of the opercle, discoloration of the body, exophthalmus and hemorrhage of the eyes. The causative organism isolated from diseased fish was identified as a $\beta$-hemolytic Streptococcus. This bacterium was not identical with any known Streptococcus species listed in Bergey's Manual of Determinative Bacteriology 8th edition. However there was a close similarity between this species and Streptococcus sp. isolated from flounder and reported by Tashio (1983). The isolated bacteria streptococcus sp. showed very high sensitivity to the SM and EM, however, it resisted to the high concentration of Penicillin. In the pathagenicity analysis, about $1.1{\times}10^9$, $1.1{\times}10^7$, $1.1{\times}10^5$, $1.1{\times}10^3$, $1.1{\times}10^1cells$/100g B.W of isolated bacteria were injected percutaneouly. The results showed that this inoculation size $1.1{\times}10^3cells$/100g B.W was the threshold for the induction of mortality in pathogenicity analysis.

• Journal of fish pathology
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• v.4 no.2
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• pp.59-70
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• 1991

In order to investigate the effects of glutathione against ceroidosis on flounder, Paralichthys olivaceus, a serial experiment was carried out at indoor tanks in Cheju province, the southern island of R.O.Korea, from October 1 to November 4 of 1991. The choosed group of flounder for this experiment, ranged from 92 to 122g in body weight, already showed a distinct histological ceroidosis in liver, spleen, kidney about six months before this experiment. They were fed on formulated diets supplemented with glutathione of 0mg, 1mg, 2mg, 5mg, 10mg per kg of diet per day. Some flounders were fed on the decomposed diet as a control continuosuly. Two individuals fed on the experimental diets were cought at an interval 7 days for 35 days and analyzed the values of blood indexs. 1. While the values of RBC, Hb, Ht, MCHC, MCV of flounder fed on the decomposed diet and the glutathione non-supplemented diet were not changed compared with the beginning levels of experiment, those fed on the glutathione supplemented diets, showed markedly increased values from 7th day of experiment and from 21th day of experiment reached to the values of healthy flounder. 2. The variation of TP, Glu, Alp, BUN, TG, T-cho, GOT and GPT were not observed in the groups fed on the control diet and glutathione non-supplemented diet. In contrast, those values in the groups fed on the glutathione supplemented diets were markedly decreased from 7th day and become constant from 21th day. 3. The effect of glutathione supplementation with high concentration in diets showed much better improvements of symptoms concequently, compared with those of low concentration diets.

• Journal of Aquaculture
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• v.19 no.1
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• pp.57-63
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• 2006

This study was conducted to investigate the effects of dietary supplementation of spirulina (SPI) and asthaxanthin (AST) on growth performance and antioxidant activity in juvenile olive flounder (Paralichthys olivaceus) in low temperature season. Total 180 fish ($27.8{\pm}0.3g$, average weight ${\pm}S.D.$) were randomly divided into 12 groups, and 3 groups were fed one of four isonitrogenous (52% CP) and isocaloric $(18.3\;MJ\;kg^{-1})$ diets containing no SPI and AST, 0.5% SPI, 0.5% AST, and 0.5% each SPI and AST (designated by diets Control, SPI, AST and SPI+AST, respectively). After 6 weeks of feeding trial, the growth performance, feed utilization, whole body composition and survival of fish were not significantly affected by the experimental diets. There were no significant differences in hematocrit, hemoglobin, alanine aminotransferase and aspartate aminotransferase of fish fed all the experimental diets. The DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay indicated numerically increased antioxidant activity in liver of fish fed the SPI diet compared to that of fish fed the control diet, even though it was not significant. The present study shows that a low level (0.5%) of dietary supplementation of SPI and/or AST does not affect growth and feed utilization and intake of juvenile olive flounder in low temperature season.

• Journal of Aquaculture
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• v.19 no.4
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• pp.254-260
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• 2006

A 6-week feeding trial was conducted to determine apparent protein and phosphorus digestibilities in order to evaluate nine different dietary protein sources in growing olive flounder, Paralichthys olivaceus. Nine diets containing fish meal analog ($BAIFA-M^{TM}$), white fish meal (WFM), flounder muscle powder (FMP), squid liver powder (SLP), leather meal (LM), soybean meal (SM), corn gluten meal (CGM), poultry by-product (PBP) or egg albumin(EA) were prepared by mixing a basal diet (BD) with one of nine test ingredients at the ratio of 7 to 3. Apparent protein digestibilities of FMP, SLP, WFM, SM, CGM, LM, PBP, $BAIFA-M^{TM}$, and EA were 94%, 92%, 86%, 82%, 75%, 72%, 72%, 71%, and 30%, respectively. Apparent phosphorus digestibilities of FMP, SLP, $BAIFA-M^{TM}$, LM, WFM, PBP, CGM, EA and SM were 77%, 72%, 65%, 55%, 54%, 50%, 20%, 20%, and 17%, respectively. Weight gain of fish fed FMP ($323^a$) was significantly higher than those of fish fed the other diets, and those of fish fed basal diet ($302^b$), SLP ($305^b$) and WFM ($308^b$) diet were significantly higher than those of fish fed SM ($274^c$), $BAIFA-M^{TM}\;(268^{cd}),\;PBP\;(261^{de}),\;LM\;(251^e),\;CGM\;(254^e)$ and EA ($181^f$). Based on the results of apparent protein digestibilities, apparent phosphorus digestibilities and weight gain, SLP, SM and $BAIFA-M^{TM}$ could be one of good protein source to replace fish meal in flounder diets.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.589-594
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• 1997

This study was performed to clarify the effect of anesthesia killing and non-bleeding on the physicochemical and rheological properties of plaice, Paralichthys olivaceus muscle at early period after death. Live plaice was killed by the two different methods: spiking at the brain instantly with bleeding and dipping In seawater containing anesthetic (2,000 ppm ethyl-aminobenzoate) for 10 min without bleeding. These samples were stored at $0^{\circ}C$ and used in checking rigor-mortis, ATP breakdown, the content of ATP and its related compounds, breaking strength, and lactate accumulation through storage. The rigor-mortis, ATP breakdown, and lactate accumulation was faster in samples killed by spiking than in samples killed by anesthesia. ATP in samples killed by anesthetic showed little breakdown until 22.5 hrs, but it was decomposed completely after 30 hrs storage. Breaking strength of samples killed by spiking at the brain instantly with bleeding decreased steadily and showed the maximum value over 10 hrs $(2207.3{\pm}60.2g)$. However, in case of the dipping fresh flesh without bleeding in seawater containing anesthetic, the value and time reached around the maximum breaking strength were $2147.8{\pm}29.0g$ and 13 hrs respectively, but it maintained constantly until 20 hrs passed. From these results, it could be suggested that anesthesia killing and non-bleeding is more effective in maintaining firmness of fresh plaice muscle than spiking killing with bleeding at the early period after death.

• Korean Journal of Environmental Biology
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• v.19 no.2
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• pp.173-181
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• 2001

To find the appearance period and distribution of Edwardsiella tarda which causes severe damage to flounder (Paralichthys olivaceus) farms in Jeju-do, the rearing seawater (inflow, rearing water, outflow) and internal organs of flounders from 5 flounder farms were examined from June, 1997 to May, 1998. The number of bacteria in seawater was counted by plating the seawater on DSSS (Double Strength Salmonella-Shigella) agar plates or by plating after cultivation of bacteria. Bacteria in internal organs were counted by plating series of dilution of homogenized organ. The results are summarized as follows. E. tarda was detected in inflow seawater of five flounder farms in July, September and November, 1997 and February, March, April of 1998. In the rearing water and outflow water, the bacterium was detected throughout the year and the number of bacteria was much higher in summer than any other seasons. A large number of E. tarda in the internal organs were detected at farm B where a track-shaped tank was used, which has the characteristics of low circulation rate and bad discharge of excrement and residuals. In contast, none of E. tarda was detected at farm A where high circulation rate and good discharge of organic materials were applied. A few number of E. tarda at farm E were detected at the same condition as the farm A. A large number of E. tarda was observed in liver and intestines among the internal organs, and the number was higher from June to September in summer.

• Journal of fish pathology
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• v.19 no.3
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• pp.267-276
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• 2006

Seventy-five streptococci were isolated from diseased olive flounder, Paralichthys olivaceus in Jeju. Their drug susceptibility and transferable multiple drug resistance were characterized. All isolates were resistant to flumequine (AR) and oxolinic acid (OA) and 26 isolates (34.7%) showed 4～6 multiple resistance of ampicillin (ABPC), AR, doxycycline (DOXY), erythromycin (EM), norfloxacin(NOR), OA and oxytetracycline (OTC) in various combinations. pST9 of a transferable R plasmid was detected from a multiple drug resistance strain, Streptococcus sp., ST9 originated from diseased flounder in Jeju, previously. We performed DNA hybridization to know the distribution of plasmid with the same DNA structure as pST9 in streptococci. Thirteen out of 60 isolates analyzed were positive in colony DNA hybridization and the part of bacteria isolated from raw meal was also hybridized with pST9. It suggested that raw meal is one of the origin of the resistance plasmid and R plasmid with DNA structure differing from pST9 is also involving in multiple drug resistance of the streptococci. In conjugation experiment, we found transferable R plasmid carrying OTC, DOXY and/or EM resistance determinant in the 13 resistance strains. all of the streptococci carrying the transferable R plasmid were similar in RAPD patterns. However, pST -type R plasmid was rare in S. iniae most frequently appearing in flounder farm.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.93-97
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• 2000

This study was carried out to investigate the effect of rotifer fed the different diets in high density culture on larval flounder Paralichthys olivaceus. Potifer was enriched with enrichment supplements, Marine ${\alpha}\;and\;{\omega}-yeast$ for 6 hours after being cultured with freshwater Chlorella for 18 hours during high density culture before it was fed to larval flounder. And rotifer was culutured with marine Chlorella and freshwater Chlorella for 24 hours during semi-continuous high density culture before it was fed to larval flounder. Culture tanks(21 working volum) set for rotifer culture in a water bath($28{\circ}C$) were continuously supplied with oxygen gas. The content of n-3 HUFA to fatty acids in rotifer(dry weight ${\%}$) enriched with Marine ${\alpha}$ for 6 hours and cultures with marine Chlorella for 24 hours were higher than that in rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. The growth and survival rates of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours and cultured with marine Chlorella for 24 hours were higher than those of larval flounder fed on rotifer enriched with ${\omega}-yeast$ for 6 hours or cultured with freshwater Chlorella for 24 hours. And the content of n-3 HUFA of larval flounder fed on rotifer enriched with Marine ${\alpha}$ for 6 hours was higher than that of larval flounder fed on other rotifers, The results from this study indicated that rotifer culture with marine Chiorelia would be suitable for the high density culture and effective diet for the growth of larval flounder.

• Fisheries and Aquatic Sciences
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• v.4 no.3
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• pp.112-119
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• 2001

Aim of this research is to investigate the effect of temperature shocks on the physiological responses of cultured olive flounder (Paralichthys olivaceus) and black rockfish (Sebastes schlegeli). Olive flounder and black rockfish were suffered with high and low temperature shocks for 4 and 8h, respectively, in laboratory conditions and then the changes in glucose, lactate, total protein, uric acid, and triglycerides-glycerol in blood plasma were analyzed. We observed that lactate and uric acid increased for up to 4h and then decreased for up to 8h by the high and low temperature shocks, and total protein decreased for up to 4h and then recovered for up to 8h by the high temperature shock in both fishes. Glucose by the high and low temperature shocks and triglycerides-glycerol by the low temperature shock increased for up to 4h, and then decreased in olive flounder, but increased for up to 8h in black rockfish. From the result, we speculated that the two fishes have an interspecific variation in the regulatory systems of glucose and triglycerides-glycero1. Glucose would play important role as an energy source during the temperature shocks and for an intermediate substance for low temperature tolerance, and glycerol of triglycerides-glycerol would play an important role for low temperature tolerance. In olive flounder, the turnover of chemical change by temperature shock took more than 4h, all chemicals returned almost to the initial level for up to 8h, but fish death followed only in 8h with the high temperature shocked group within two days. Therefore, we suggested that fish would be damaged severely by the longer time exposure of high temperature and mortality would occur after a certain time later than the shocked time as a post-effect.