• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1271-1278
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• 2007

In this study, the ability of Styela clava or Styela plicata to reduce ethanol-induced hepatotoxicity and hepatic and leucocytic DNA damages was evaluated. Twenty four male SD rats were given 25% ethanol containing water (ad lib, p.o.) and divided into 3 groups; ethanol treated control group (EtOH), ethano1+3% S. clava (EtOH+SC), and ethano1+3% S. plicata (EtOH+SP). After 6 weeks, the supplementation of S. clava reduced the plasma ALT, ALP and LDH activities significantly (p<0.05), while S. plicata induced significant decrease in the plasma LDH activity only. The comet assay was employed to quantify the alcohol-induced DNA damage in rat hepatocytes and leucocytes. A significant protective effect on hepatic and leucocytic DNA damages was observed in S. clava or S. plicata supplemented groups compared to the EtOH control group. The hepatic DNA damage was correlated positively with plasma ALP and LDH activities. These results demonstrated that S. clava or S. plicata supplementation protected alcohol-induced hepatic and leucocytic DNA damage.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.4
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• pp.302-307
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• 2014

To examine the trophic ecology of the ascidian Styela clava in an aquaculture system of Korea, stable carbon and nitrogen isotopes were analyzed monthly in S. clava, coarse ($>20{\mu}m$, CPOM) and fine particulate organic matters ($0.7<<20{\mu}m$, FPOM). CPOM (means: $-18.5{\pm}1.2$‰, $9.3{\pm}0.7$‰) were significantly higher ${\delta}^{13}C$ and ${\delta}^{15}N$ values than those ($-20.5{\pm}1.5$‰, $8.4{\pm}0.5$‰) of FPOM. S. clava had mean ${\delta}^{13}C$ and ${\delta}^{15}N$ values of $-18.9({\pm}1.7)$‰ and $11.6({\pm}0.7)$‰, respectively. S. clava were more similar to seasonal variations in ${\delta}^{13}C$ and ${\delta}^{15}N$ values of FPOM than those of CPOM, suggesting that they rely largely on the FPOM as a dietary source. In addition, our results displayed that the relative importance between CPOM and FPOM as dietary source for the ascidians can be changed according to the availability of each component in ambient environment, probably reflecting their feeding plasticity due to non-selective feeding irrespective of particle size. Finally, our results suggest that dynamics of pico- and nano-size plankton (i.e., FPOM) as an available nutritional source to S. clava should be effectively assessed to maintain and manage their sustainable aquaculture production.

• 한국수산학회:학술대회논문집
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• 2005.05a
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• pp.41-42
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• 2005

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1997.06a
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• pp.211-212
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• 1997

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1674-1678
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• 2008

Antioxidant activities of extracts from parts of Styela clava (Korean name: miduduk) were evaluated. Each part of S. clava－fresh (FR) or freeze dried (FD) state－was extracted by four different solvents (methanol, ethanol, acetone, and water). Antioxidant activity of the extracts was determined by radical scavenging activity assay and reducing power assay. Radical scavenging activity was the highest in distilled water extract of FD flesh, and reducing power was the highest in acetone extract of FR flesh. These results indicate that the antioxidant property of S. clava is variable with the structural part, type of extraction solvent, and drying condition.

• Animal Systematics, Evolution and Diversity
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• v.14 no.2
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• pp.105-116
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• 1998

Two species of notodelophyid copepods, Doroixys uncinata Kerschner, 1879 and Dorophygus rigidus Ooishi, 1962 are redescribed on the basis of the specimens taken from the ascidians deposited at the Department of Biological Science, Ewha Womans University. The former species were taken from the test of the commpound ascidian Aplidium glabrum(Verrill), and the latter from the body cavity of the solitary ascidians Cnemidocarpa irene(Hartmeyer) and Stylea tokiokai Nishikawa.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.646-652
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• 2004

With the aim of using a cosmetic material, chondroitin sulfates extracted from midduck tunics (Styela clava) and munggae tunics (Halocynthia roretzi) were examined in vitro with two cell lines for cell toxicity, collagen synthesis, cell growth and recovery ability after U.V. irradiation. Cell toxicity test with A 431 and CCD 1108Sk was able to observe high activity between 400 and 600 $\mu\textrm{g}$/m while standard chondroitin sulfate (CS) purchased from Sigma was showed at 80 $\mu\textrm{g}$/mL. Even fraction 1 and 2 collected from chondroitin sulfates originated from midduck appeared having the highest activity between 600 and 1000 $\mu\textrm{g}$/mL, but slightly lower compared to crude chondroitin sulfates from both mideduck and munggae. In cell growth examination, it was not able to find significant differences between chondroitin sulfates used. Both crude chondroitin sulfates were exhibited the highest activity for two cell lines except that of mideduck which was showed activity for CCD 1108Sk. CS, fraction 1 and 2 from midduck were not able to demonstrate a significant activity in collagen synthesis. On the contrary, crude chondroitin sulfates from both munggae and midduck were showed the highest activity at 100 and 50 $\mu\textrm{g}$/mL with only CCD 1108Sk. The recovery ability after U.V. irradiation with crude chondroitin sulfates from both munggae and midduck were showed high activity at 400 $\mu\textrm{g}$/mL with CCD 1108Sk and A 431. But there were no activity observed in fractions examined, As a consequence, the crude chondroitin sulfates from both munggae and midduck might not only be available as a cosmetic material but also useful for increasing some activity by blending properly.

• Korean Journal of Environmental Biology
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• v.32 no.3
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• pp.216-224
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• 2014

Decrease in dissolved oxygen concentrations associated with temperature fluctuation is an important criteria to evaluate the mortality rate of the species. Based on this parameter, we investigated the survival rate, physiological response and histological change of warty sea squirt. It was found that the survival rate of the warty sea squirt species was 63.3% at $23^{\circ}C$ and 56.6% at $26^{\circ}C$ respectively. However, exposure of six days at $29^{\circ}C$ caused deaths among species, which indicated the 6day-$LT^{50}$ of the tested species to be $24.58^{\circ}C$ ($19.48{\sim}35.48^{\circ}C$). Further, after 11 day of exposure, the dissolved oxygen concentration has been found to decrease, with the survival rate of 20% at $4.0mg\;L^{-1}$ and deaths at $2.0mg\;L^{-1}$, thus 11day-$LC^{50}$ calculated to be $3.88mg\;L^{-1}$ ($3.29{\sim}4.57mg\;L^{-1}$). In addition, decrease in rate of oxygen consumption and excretion of ammonia was also noted at this critical water temperature and dissolve doxygen concentration. Moreover, there has been common histopathological changes were observed in warty sea squirt's gill pouch, digestive tract, and tunic as follows such as: proliferation of epithelial cells, condensation and necrosis, permeation of phagocyte and blood cell, loss of cilium and muscular fiber degeneration. Based on our study results, we suggest that these parameters can also be useful to evaluate the survival rate and physiological response in other species.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.607-611
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• 2017

The purpose of this study is to present the concept of merchandising Styela clava HERDMAN developed in 2016. The main contents of this study are analyzing the general condition of Styela clava HERDMAN, We intend to promote stable and sustainable development of Korean aquaculture by activating the aquaculture insurance system by expanding coverage items and coverage, and increasing insurance coverage.

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.378-379
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• 2011