• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.11 no.2
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• pp.49-67
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• 2006

A mesocosm, an artificial tidal flat ecosystem, was constructed outdoors to simulate in situ physical and biochemical environmental conditions of natural tidal flat as much as possible. During the experiment from February to August 2004, the study was focused on the biogeochemical variations of superficial water and porewater after introduction of freshwater into the mesocosm. The mesocosm has three experimental conditions; SW-M-T: maintaining the saline water of approximately 20 psu; FW-M-T: complete exchange of freshwater ul the mesocosm with continuous mixing of water column: FW-NM-T: complete exchange of saline water to freshwater in the mesocosm without mixing of water column. Mass extinction of benthic macrofauna appeared due to drastic decrease of porewater salinity from 20 psu to less than 10 psu between the 63th and 91st day of freshwater introduction in FW-M-T and FW-NM-T. Throughout the periods, 7/8 of bivalves and 2/3 of polychaete populations have been extinguished in the sediment. In FW-NM-T, as temperature rises, both evident decrease of DO in water column and active release of DIP from sediment were observed. ${NO_3}^-$ was removed from water column into sediment throughout the periods. Therefore extremely low ${NO_3}^-$ was found during late spring and summer. Whereas ${NH_4}^+$ exhibited only $1/2{\sim}1/8$ of ${NO_3}^-$ concentration. Unexpectedly even after mass extinction of benthic macrofauna, we were not able to find high ${NH_4}^+$. This mesocosm study suggests that when fresh water introduce to natural tidal flat, its sediment activity functions as a potential source of DIP, but a sink of ${NO_3}^-$.

• Journal of Aquaculture
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• v.5 no.1
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• pp.29-67
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• 1992

Life cycle and seed production of the freshwater prawn, Macrobrachium nipponense, were studied and the results are as follows : 1. Larval development : Embryos hatched out as zoea larvae of 2.06 mm in mean body length. The larvae passed through 9 zoea stages in $15{\~}20$ days and then metamorphosed into postlarvae measuring 5.68 mm in mean body length. Each zoea stage can be identified based on the shapes of the first and second antennae, exo- and endopodites of the first and second pereiopods, telson and maxillae. 2. Environmental requirements of zoea larvae : Zoea larvae grew healthy when fed with Artemia nauplii. Metamorphosing rate was $65{\~}72{\%}$ at $26{\~}28\%$ and $7.85{\~}8.28\%_{\circ}Cl.$. The relationship between the zoeal period (Y in days) and water temperature (X in $^{\circ}C$) is expressed as Y=46.0900-0.9673X. Zoeas showed best survival in a water temperature range of $26{\~}32^{\circ}C$ (optimum temperature $28^{\circ}C$), at which the metamorphosing rate into postlarvae was $54{\~}72\%$ The zoeas survived more successfully in chlorinity range of $4.12{\~}14.08{\%_{\circ}}Cl.$, (optimum chlorinity $7.6{\~}11.6\;{\%_{\circ}}Cl.$.), at which the metamorphosing rate was $42{\~}76{\%}$. The whole zoeal stages tended to be longer in proportion as the chlorinity deviated from the optimum range and particularly toward high chlorinity. Zoeas at all stages could not tolerate in the freshwater. 3. Environmental requirements of postlarvae and juveniles : Postlarvae showed normal growth at water temperatures between $24{\~}32^{\circ}C$ (optimun temperature $26{\~}28^{\circ}$. The survival rate up to the juvenile stage was $41{\~}63{\%}$. Water temperatures below $24^{\circ}C$ and above $32^{\circ}$ resulted in lower growth, and postlarvae scarcely grew at below $17^{\circ}C$. Cannibalism tended to occur more frequently under optimum range of temperatures. The range of chlorinity for normal growth of postlarvae and juveniles was from 0.00 (freshwater) to $11.24{\%_{\circ}}Cl.$, at which the survival rate was $32{\~}35\%$. The postlarvae grew more successfully in low chlorinities, and the best growth was found at $0.00\~2.21{\%_{\circ}}Cl.$. The postlarvae and juveniles showed better growth in freshwater but did not survive in normal sea water. 4. Feeding effect of diet on zoea Ilarvae : Zoea larvae were successfully survived and metamorposed into postlarvae when fed commercial artificial plankton, rotifers, and Artemia nauplii in the aquaria. However, the zoea larvae that were fed Artemia nauplii and reared in Chlorella mixed green water showed better results. The rate of metamorphosis was $68\~{\%}75$. The larvae fed cow live powder, egg powder, and Chlorella alone did not survive. 5. Diets of postlarvae, juveniles and adults : Artemia nauplii and/or copepods were good food for postlarvae. Juveniles and adults were successfully fed fish or shellfish flesh, annelids, corn grain, pelleted feed along with viscera of domestic animals or fruits. 6. Growth of postlarvae, juveniles and adults : Under favorable conditions, postlarvae molted every five or six days and attained to the juvenile stage within two months and they reached 1.78 cm in body length and 0.17 g in body weight. The juveniles grew to 3.52 cm in body length and 1.07 g in body weight in about four months. Their sexes became determinable based on the appearance of male's rudimental processes (a secondary sex character) on the endopodites of second pereiopods of males. The males commonly reached sexual maturity in seven months after attaining the postlarvae stage and they grew to 5.65 cm in body length and 3.41 g in body weight. Whereas the females attained sexual maturity within six to seven months, when they measured 4.93 cm in body length and 2.43 g in body weight. Nine or ten months after hatching, the males grew $6.62{\~}7.14$ cm in body length and $6.68{\~}8.36$ g in body weight, while females became $5.58{\~}6.08$ cm and $4.04{\~}5.54$ g. 7. Stocking density : The maximum stocking density in aquaria for successful survival and growth was $60{\~}100$ individuals/$\ell$ for zoeas in 30-days rearing (survival rate to postlarvae, $73{\~}80{\%}$) ; $100{\~}300$ individuals/$m^2$ for postlarvae of 0.57 cm in body length (survival rate for 120 days, $78{\~}85{\%}$) ; $40{\~}60$ individuals/$m^2$ for juveniles of 2.72 cm in body length (survival rate for 120 days, $63{\~}90{\%}$) : $20{\~}40$ individuals/$m^2$ for young prawns of 5.2 cm in body length (survival rate for 120 days, $62\~90{\%}$) ; and $10\~30$ individuals/$m^2$ for adults of 6.1 cm in body length (survival rate for 60 days, $73\~100{\%}$). The stocking density of juveniles, youngs and adults could be increased up to twice by providing shelters.

• 한국유가공학회:학술대회논문집
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• 2007.09a
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• pp.49-58
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• 2007

Inflammatory process leads to the well-known mucosal damage and therefore a further disturbance of the epithelial barrier function, resulting abnormal intestinal wall function, even further accelerating the inflammatory process[1]. Despite of the records, etiology and pathogenesis of IBD remain rather unclear. There are many studies over the past couple of years have led to great advanced in understanding the inflammatory bowel disease(IBD) and their underlying pathophysiologic mechanisms. From the current understanding, it is likely that chronic inflammation in IBD is due to aggressive cellular immune responses including increased serum concentrations of different cytokines. Therefore, targeted molecules can be specifically eliminated in their expression directly on the transcriptional level. Interesting therapeutic trials are expected against adhesion molecules and pro-inflammatory cytokines such as TNF-${\alpha}$. The future development of immune therapies in IBD therefore holds great promises for better treatment modalities of IBD but will also open important new insights into a further understanding of inflammation pathophysiology. Treatment of cytokine inhibitors such as Immunex(Enbrel) and J&J/Centocor(Remicade) which are mouse-derived monoclonal antibodies have been shown in several studies to modulate the symptoms of patients, however, theses TNF inhibitors also have an adverse effect immune-related problems and also are costly and must be administered by injection. Because of the eventual development of unwanted side effects, these two products are used in only a select patient population. The present study was performed to elucidate the ability of TNF-${\alpha}$ antibodies produced in sheep colostrums to neutralize TNF-${\alpha}$ action in a cell-based bioassay and in a small animal model of intestinal inflammation. In vitro study, inhibitory effect of anti-TNF-${\alpha}$ antibody from the sheep was determined by cell bioassay. The antibody from the sheep at 1 in 10,000 dilution was able to completely inhibit TNF-${\alpha}$ activity in the cell bioassay. The antibodies from the same sheep, but different milkings, exhibited some variability in inhibition of TNF-${\alpha}$ activity, but were all greater than the control sample. In vivo study, the degree of inflammation was severe to experiment, despite of the initial pilot trial, main trial 1 was unable to figure out of any effect of antibody to reduce the impact of PAF and LPS. Main rat trial 2 resulted no significant symptoms like characteristic acute diarrhea and weight loss of colitis. This study suggested that colostrums from sheep immunized against TNF-${\alpha}$ significantly inhibited TNF-${\alpha}$ bioactivity in the cell based assay. And the higher than anticipated variability in the two animal models precluded assessment of the ability of antibody to prevent TNF-${\alpha}$ induced intestinal damage in the intact animal. Further study will require to find out an alternative animal model, which is more acceptable to test anti-TNF-${\alpha}$ IgA therapy for reducing the impact of inflammation on gut dysfunction. And subsequent pre-clinical and clinical testing also need generation of more antibody as current supplies are low.

• Development and Reproduction
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• v.4 no.2
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• pp.153-160
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• 2000

In this study, genetic variation in the 5 strains of 2N-cont, meiotic-G2N, mitotic-G2N and two types of clones with different genetic backgrounds was investigated by developing their tolerance to water temperature and salinity, which is a physiological trait, into a quantitative trait. The temperature was set at 19$^{\circ}C$, 22.5$^{\circ}C$, 25$^{\circ}C$ and 30$^{\circ}C$, each of which was combined with 0$\textperthousand$, 15$\textperthousand$ and 30$\textperthousand$ of salinity respectively, making 12 groups in all. In the mean survival time (MST), samples with 15$\textperthousand$ of salinity showed the longest survival time at all temperatures. The 2N-cont had the longest 126.16 h followed by clone-11 and clone-15 surviving for 113.22 h and 91.05 h respectively. Gynogenetic diploids showed the shortest 87,32 h and 36.56 h. At 22.5 and 25$^{\circ}C$, MST of each strain was significantly short, showing similar results to those of the groups at 19$^{\circ}C$. The 2N-cont had the longest MST while clones had a longer MST than gynogenetic diploids. This could be due to gynogenesis which causes homozygosis among malignant harmful genes, leading to its appearance in populations and resulting in early death in individuals with such genes. On the other hand, MST of clones was longer than that of gynogenetic fish. This could be because the 1st gynogenetic generation, which is a parental population, has already had its malignant genes removed, while the clones of the 2nd gynogenetic generation have had their superior genes fixed as well as their tolerance and survival improved. When temperature was raised to 22.5$^{\circ}C$ and 25$^{\circ}C$, increase in variation was observed in gynogenetic diploids and decrease in clones in 15$\textperthousand$ of salinity. This shows that such a trait is genetic to a certain extent. Consequently, if this character is developed into a quantitative trait and applied to selective breeding, it could be a useful character to secure superior strains and individuals, and also it would be possible to improve populations genetically through selection.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.273-281
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• 2004

A feeding trial was conducted with Euglena strains grown under different media. The effect of supplementation of Euglena on the performance, nutrient availability and fatty acid composition of breast muscle was studied. In experiment I, two hundred ten hatched broiler chicks (Ross) were assigned to seven dietary treatments for 5 weeks. Each treatment consisted of 3 replications with 10 birds each. Control diet was formulated to have $22\%$ CP and 3,150 kcal ME/kg for starter diet, $19\%$ CP and 3,200 kcal ME/kg for finisher diet. Euglena gracilis Z. (EG) was added to control diet at the plevel of 0.25, 0.5, $1.0\%$ and Euglena gracilis Z. bleached and DHA enriched (EGBD; a strain mutated by streptomycin and cultivated in DHA enriched medium) at the level of 0.5, 1.0, $2.0\%$ in the diet. In experiment 2, two hundred fifty hatched broiler chicks (Ross) were assigned to five dietary treatments: T1; Control, T2; T1 + Euglena gracilis Z. DHA enriched (EGD; cultivated in DHA enriched medium) $0.5\%$, T3; T1 + EGD $1.0\%$, T4; T1 + EGBD $0.5\%$, T5; T1 + EGBD $1.0\%$. The weight gain and feed consumption were measured weekly. Fatty acid composition of breast muscle was determined. In experiments I and 2, Euglena supplementation had no significant effects on weight gain, feed intake and feed conversion ratio. In experiment 1, EGBD treatments significantly increased DHA concentration but decreased concentration of linoleic acid and arachidonic acid in breast muscle. EGBD 2% treatment showed the highest DHA concentration (14.27%) which is 3.9 times of that of the control ($3.66\%$). In experiment 2, $1.0\%$ EGBD treatment showed highest EPA, lignoceric acid and DHA level in breast muscle (P<0.05). Also, EGD treatments significantly increased DHA and EPA concentration. It was concluded that EGBD and EGD can be supplemented to broiler diet to produce DHA enriched broiler meat.

• Ocean and Polar Research
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• v.37 no.1
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• pp.49-59
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• 2015

Spatial variation in the reproductive effort of Manila clam Ruditapes philippinarum is often closely associated with variation in the seawater temperature and food availability, which determines gonad maturity and the quantity of gamates produced during spawning. Previous studies also have reported that severe infection by the protozoan parasite Perkinsus olseni exerts a negative impact on clam reproduction, retarding gonad maturation or decreasing the reproductive effort. In the present study, we investigated impacts of P. olseni infection on the reproductive condition of Manila clam during a spawning season. Histology revealed that 54% of female clams in Wando off the south coast were in spawning, while only 10% of the female from Gomso and 0% of the female from Seonjaedo in Gyeonggi bay off the west coast were engaged in spawning at the end of May in 2004. Ray's fluid thioglycollate media (RFTM) assay was applied to assess P. olseni infection and indicated that the infection intensity in Wando ($3,608,000{\pm}258,000cells/g$ wet tissue) was significantly higher than the levels in Gomso ($1,305,000{\pm}106,000cells/g$ wet tissue) and Seonjaedo ($1,083,000{\pm}137,000cells/g$ wet tissue, p < 0.001). The size of the ripe female follicle determined from histology was significantly smaller in Wando ($0.032mm^2$) compared to the sizes in Gomso ($0.059mm^2$) and Seonjaedo ($0.052mm^2$, p < 0.05). Accordingly, the number of ripe eggs in the follicle was significantly fewer among clams in Wando (14) compared to the numbers determined in Gomso (23) and Seonjaedo (22). The absolute quantity of egg in ripe clams from Wando (31.01 mg) was also significantly smaller than Seonjaedo (61.79 mg) and Gomso (133.3 mg). Quantity of total protein, carbohydrate, and lipid in the tissue in the Wando samples was significantly smaller than the quantities determined in Gomso and Seonjaedo (p < 0.001). The observed poor reproductive condition and proximate tissue composition of the females in Wando were, in part, explained by the extremely high level of the parasites, sapping the ability to store energy in the host tissues, which is used in tissue growth and the egg production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.3
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• pp.343-352
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• 1998

The relationship between summer hypoxia in bottom water layer and benthic community structure was discussed at forty sampling stations in semi-enclosed Youngsan River estuarine bay, Korea. The oxygen deficient layer less than $2.0 mg/\ell$ was widely developed in the inner estuarine stations in summer due to the summer stratification. A total of 141 species was occurred, with a mean density of $1,923 ind./m^2$ and biomass of $79.44\;g/m^2$ in summer season. The species number was significantly increased with the increment of the bottom dissolved oxygen, whereas density and biomass were partially correlated within the low oxygen level of $2.0\;mg/\ell$. These results imply that benthic community structures are affected by bottom oxygen depletion in summer. Cluster analysis showed that the benthic community could be classified into three station groups. These station groups from the species composition coincided with the groups based on the environmental factors. This fact suggests that the overall spatial distribution of macrozoobenthos in Youngsan River estuarine bay in summer should be controlled by the summer hypoxia and clay content of the area. Group-I was located the innermost estunrine bay from Mokpo Harbour to near the dike, where summer hypoxia was developed and one bivalve Theora fragilis, two polychaetes, Tharyx sp. and Lumbrineris longifolia were dominated. Group-II, the central transitory area of the estuarine bay between two another stational groups, where two bivalves Theora fragilis, Raetellops pulchella and a polychaete Tharyx sp. predominated with relatively low density compared to that of Group-I. Group-III, the mouth part of the estunrine bay exposed to the open sea, where a polychaetes Poecilochaetus johnsoni and a bivalve Yoldia Johanni predominated.

• Journal of Aquaculture
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• v.13 no.4
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• pp.277-284
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• 2000

Rabbitfish hatchlings were given a mixed food of rotifers (Brachionus rotundiformis) and trochophore larvae of oyster. Only the oyster-trochophore larvae were found in the gut of 62-h old fish larvae. The fish larvae, fed on rotifer and ciliate alone did not survive. However, their survival increased to 3.3 % on the 10th day after hatching, when trochophore was supplemented. Corresponding with the accelerated growth, the number of rotifers consumed increased from 11 in a 5-day old fish to 165 in a IS-day old fish. In a field ecosystem containing live diatom, Nannochloropsis oculata, rotifers and copepods, fish larvae were shocked and the oyster's trochophore larvae were fed from 2 to 7 days after hatching. A total of 76,000 seedling were produced after 50 days of hatching with 12.7 % survival. Mean total length and body weight were 65.6 mm and 3.4 g, respectively. Growth of body length (BL), body height (BH), body weight (BW) and head length (HL) as a function of the total length (TL) showed regressional relationships as follows; BL=0.8565 TL+0.0852 ($t^2$=0.9996); BH=0.3207 TL - 0.5052 (($t^2$=0.9641) BW=0.0652 TL2.3508 (($t^2$=0.9925); HL=0.2595 TL - 0.1898 (($t^2$=0.9901)

• Journal of Aquaculture
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• v.20 no.4
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• pp.270-277
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• 2007

White spot syndrome virus (WSSV) which is the most serious threat to cultured shrimp around the world has given enormous economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. WSSV has strong infectivity as well as virulence and it can be rapidly transmitted among shrimps in ponds by cannibalism of infected ones. Polyculture of shrimps with carnivorous fish has been applied in commercial shrimp farms to suppress or delay the viral outbreak because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of a carnivorous fish, river puffer Takifugu obscurus on white shrimp Litopenaeus vannamei, polyculture trials in laboratory scale of WSSV-infected and non-infected shrimps with river puffer were conducted in concrete round tanks of $28.26\;m^2$ in surface area as followings: 1) juvenile shrimps (B. W. 0.62 g) with 5 months old puffer (B. W. 11.60 g) cultured for 8 days, and 2) sub-adult shrimps (B. W. 6.84 g) with 16 months old puffer (B. W. 85.82 g) cultured for 5 days in order to know the effects according to size difference of cultured animals. In polyculture of juvenile shrimp with 5 months old puffer, survival rates of infected and non-infected shrimps were 46.0% and 89.1% respectively and in that of sub-adult shrimp with 16 months old puffer those were4% and 48% respectively. The results showed that puffer tends to selectively prey on virus infected shrimps among infected and non-infected ones in a limited space with although there is difference in predatory rate with age and density of animals. Regardless of different densities and ages of animals as well as health condition of shrimps, however, there were low differences in daily biomass of shrimp consumed per kg body weight of puffer. This finding suggests that puffer preys on healthy shrimps when moribund shrimps were not sufficient. Therefore, farmers should consider the total biomass of puffer as well as density and stocking time when they stock puffer into shrimp ponds for polyculture.

• Journal of Sasang Constitutional Medicine
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• v.10 no.2
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• pp.533-564
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• 1998

In order to know the effect of proliferation and differentiation on edipocyte 3T3-L1 by prescriptions and herbs, Taeyangin(太陽人)'s Okapijangcheok-tang(五加皮壯脊湯) Mihudeungsikjangtang Acanthopanacis Cortex(五加皮) Phragmitis Rhizoma(蘆根) and Taeumin(太陰人)'s Taeumjowi-tang(太陰調胃湯) Cheongsimyonja-tang(淸心蓮子湯) Cheongpaesagan-tang(淸肺瀉肝湯) Galkeunbupyong-tang(葛根浮萍湯) Coicis Semen(薏苡仁) Rhei Undulati Rhizoma(大黃) Mori Cortex(桑白皮) Ulmi Cortex(楡根白皮) Holotrichia Vermiculus Kalopanaxii Cortex(海桐皮) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根), were used and had some effects. 1. The proliferation effect of edipocyte 1) At the Taeyangin(太陽人)'s prescriptions and herbs, Okapijangcheok-tang(五加皮壯脊湯) Mihudeungsikjang-tang Acanthopanacis Cortex(五加皮) have a control effect at the boiling water-extract and ethyl alcohol-extract. Phragmitis Rhizoma(蘆根) have a control effect at the ethyl alcohol-extract. 2) At the Taeyangin(太陽人)'s prescriptions and herbs, Taeumjowi-tang(太陰調胃湯) Cheongsimyonja-tang(淸心蓮子湯) Cheongpaesagan-tang(淸肺瀉肝湯) Galkeunbupyong-tang(葛根浮萍湯) have a control effect at the boiling water-extract and ethyl alcohol-extract. Coicis Semen(薏苡仁) Rhei Undulati Rhizoma(大黃) Morl Cortex(桑白皮) Ulmi Cortex(楡根白皮) Kalopanaxii Cortex(海桐皮) · Ephedrae Herba(麻黃) of the boiling water-extract, Holotrichia Vermiculus Kalopanaxii Cortex(海桐皮) of ethyl alcohol-extract have a control effect on edipocytes. Rhei Undulati Rhizoma(大黃) Ulmi Cortex(楡根白皮) Ephedrae Herba(麻黃) of high-density have a cyto-toxicity. 2. The differentiation effect of edipocyte 1) At the Taeyangin(太陽人)'s prescriptions and herbs during the natural differentiation, Phragmitis Rhizoma(蘆根) of the boiling water-extract, Okapijangchek-tang(五加皮壯脊湯) Acanthopanacis Cortex(五加皮) of the ethyl alcohol-extract have a cyto-toxicity on the first-differentiation. 2) At the Taeumin(太陰人)'s prescriptions and herbs during the natural differentiation, Ulmi Cortex (楡根白皮) Kalopanaxii Cortex(海桐皮) of the boiling water-extract have a cyto-toxicity on the first-differentiation. Cheongsimyonja-tang(淸心蓮子湯) Ephedrae Herba(麻黃) of ethyl alcohol-extract have a control effect on the redifferentiation. 3) At the Taeyangin(太陽人)'s prescriptions and herbs on the first-differentiation during the induced differentiation, Acanthopanacis Cortex(五加皮) of ethyl alcohol-extract has a control effect. Okapijangchek-tang(五加皮壯脊湯) Acanthopanacis Cortex(五加皮) Phragmitis Rhizoma(蘆根) of the boiling water-extract have a cyto-toxicity. 4) At the Taeumin(太陰人)'s prescriptions and herbs on the first-differentiation during the induced differentiation, Coicis Semen(薏苡仁) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根) of the boiling water-extract and Ephedrae Herba(麻黃) of the ethyl alcohol-extract have a control effect. Kalopanaxii Cortex(海桐皮) of the boiling water-extract and the ethyl alcohol-extract has a cyto-toxicity. Considering this result, the Taeyangin(太陽人) Taeumin(太陰人)'s prescriptions and herbs have a control effect on edipocytes during the proliferation. Acanthopanacis Cortex(五加皮), Coicis Semen(薏苡仁) Ephedrae Herba(麻黃) Imperatae Rhizoma(白茅根) have a control effect on edipocytes during the induced differentiation. In the future, for treating a obesity need a vivo assay and hope this study to help to know the mechanisms of obesity.