• The Korean Journal of Malacology
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• v.25 no.3
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• pp.197-201
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• 2009

This study was conducted to investigate the genetic characteristics of wild population of Pacific abalone, Haliotis discus hannai in Dokdo island. We used six polymorphic microsatellite marker to investigate the genetic diversity and population structure. The loci Hdh1321 and Hdh512 had the highest number of allele (34 and 22 respectively) and loci Hdh145 and Awb083 had the lowest (5 and 7 respectively). The mean number of allele per locus was 14.8. The average observed and expected heterozygosities were 0.664 and 0.824 respectively, and the average $F_{IS}$ was 0.195. We compared the population genetic parameters of Dokdo population with previously published data of the same species. At the result, the parewise $F_{ST}$ test showed significant difference between the Dokdo population and six populations (published data), suggesting that the genetic relationship of Dokdo population was separated from six populations.

• Journal of fish pathology
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• v.26 no.2
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• pp.117-121
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• 2013

Three commercial exfoliating reagents, product A (main components: citric acid and vitamin C), B (herb) and C (nicotinamide), were used to study their exfoliation effect on abalone, Haliotis discus hannai from the substrate. The exfoliating reagents A, B, C and oxytetracycline (OTC, control) of 6-31.25 g/L and 12-37.5 g/L exfoliated 81.2-84.8% and 90.3-95% of abalone, respectively. Post-treatment recovery time for the abalone was similar for all the reagents except product C. Recovery period for the abalone immersed in OTC for 5-20 second was slightly shorter than the reagents A, B and C; however, no mortality was observed in any group except with the reagents B (concentration: 20 g/L, immersion time: 5 sec) and C (12 g/L, 10 and 20 sec) that showed negligible mortality of 3.3%. Higher concentration and longer treatment with the reagents resulted in longer recovery time of the detached abalone. Although abalone exposed to the reagents needs slightly longer time to recover than that to OTC, the exfoliation effect is much similar. These results indicate that the commercial exfoliating reagents can replace OTC to detach abalone, though they need to be cautiously handled.

• Journal of fish pathology
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• v.25 no.2
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• pp.123-126
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• 2012

Exfoliation of fouling abalone, Haliotis discus hannai from shelters by commercial oxytetracycline (OTC) was observed in culture farms. In the present study, different components of OTC for exfoliation of abalone were investigated to understand how to work. Abalone were detached from shelter in 14,000 ppm of commercial OTC (main ingredients of OTC: OTC-hydrogen chloride (HCl), 50%; glucose, 49%; blue pigment, <1%), but not below 8,000 ppm. A 95% of exfoliation rate was observed in OTC-HCl (7,000 ppm, pH 2.8) but no exfoliation in OTC-HCl (7,000 ppm, pH 5.0), glucose (7,000 ppm) or blue pigment (140 ppm). Moreover 100% exfoliation rate was observed in HCl-seawater of pH 2.8. These results indicate that HCl is the component resulting in exfoliation of the fouling abalone. Abalone was detached in HCl solution (pH 2.5-3.2) within 2 min. However, a lower pH and longer treatment resulted in delayed recovery of the detached abalone. Thus, exfoliation of fouling abalone can be achieved by a low pH treatment with cautious handling.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.835-840
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• 2006

The purpose of this study was to examine the in vitro effects of body and visceral portion of Haliotis discus hannai on angiotensin converting enzyme (ACE) activity and antioxidant and anticoagulant capacity. Extracts from both abalone body and visceral portion using 80% ethanol showed a high ACE-inhibitory effect. While ACE-inhibitory effect of extracts of the body part was dose-dependent, visceral extracts did not show any difference by the level of concentration. ACE-inhibitory effect of the visceral portion was much higher than that of the body. Antioxidant capacity was increased with increasing concentration of 80% ethanol body extracts although the capacity was low. The 80% ethanol visceral extracts showed a similar level of antioxidant capacity to the body extract in low concentration. Water extracts showed a dose-dependent increase in the activity. There was no significant difference in the antioxidant activity between the body and the visceral part. Anticoagulant capacity of 80% ethanol extracts, which was measured using prothrombin time(PT), was higher in the body part than the visceral part. Water extracts of Haliotis discus showed no any significant effect on anticoagulant capacity. The in vitro effects were also examined after Haliotis discus was refrigerated for 48 hours. Higher ACE-inhibitory effect was observed for the visceral portion than the body, in particular, before the sample was refrigerated. Antioxidant effect of Haliotis discus increased with increasing level of the sample before it was refrigerated. However, there was a significant difference between the body and the visceral part, which showed significantly higher capacity. There was no significant difference between the body and visceral part in PT regardless of refrigeration. While activated partial thromboplastin time (APTT) showed no significant difference between body and visceral part, there was a significant difference in the capacity between before and after the refrigeration, which showed much lower coagulant capacity.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.83-92
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• 2015

The effect of different intermediated rearing method by expanding the attached floor space in order to highly density culture on the growth characteristics and survival rate of the juvenile abalone, Haliotis discus hannai, were investigated in land-based tanks. The intermediated culture methods was determined thru the shelter counts and layer for 10 month with two replicates : the single layer shelter (SLS), the double layer shelter (DLS), the triple layer shelter (TLS) and the single layer shelter under net cage (SLSNC). In addition, the culture on shallow race way tank had to set up as culture of the ditch raceway tank (CDRT) and the floor race way tank (CFRT). In the growth performance of reared abalone (initial mean shell length $54.18{\pm}7.39mm$ and weight $1.93{\pm}0.14g$) at experimental tanks, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth was not significant at each experimental tanks except SLSNC. As well as too, weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to weight was not significant at each experimental tanks except SLSNC, too. Survival rates of CDRT and CFRT was lower than those of different experimental tanks (P < 0.05). Therefore, these results is showed that high density different intermediated rearing method by expanding the attached floor space for juvenile H. discus hannai was not have difference as growth performance and survival rate both one layer shelter and multi layer shelter. Also, it is considered that shallow race way tank was not useful rearing for the juvenile intermediate culture of H. discus hannai in land based.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.353-361
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• 2014

In order to investigate the effects of copper alloy on abalone physiology, we studied survival rate, respiration, excretion rate, and heavy metal accumulation in each organ of adults and spats. The survival rate of spats and adults showed 27-60% and 63-83% respectively, higher survival rate in adults. In particular, 100% of copper panel led to lowest survival rate and there was no sharp distinction according to copper alloy composition. The respiration rate and excretion rate of ammonia nitrogen was $1.81mgO_2/g$ D.W./h and 0.43 mg $NH_4-N/g$ D.W./h respectively at 100% of copper panel. In other words, there was a high significant difference at the level, but no significant difference at other test levels (P < 0.05). The atomic ratio (0: N) hit the lowest at the 100% of copper panel showing 3.79 and no significant differences were seen among other test groups with 6.57-7.18 of a very low range. This means that the species might have undergone nutritional stress. In case of copper accumulation, the 100% copper panel group showed the highest level in hepatopancreas and muscle showing 6.91 mg/kg and 1.60 mg/kg respectively but the rest of groups showed similar levels. Zinc accumulation raised at Cu-Zn alloy panel had high significance showing 18.50 mg/kg and 1.10 mg/kg in hepatopancreas and muscle respectively (P < 0.05). To sum up, a cage net made of 100% pure copper is expected to have a negative effect on abalone in light of survival rate, heavy metal accumulation, and atomic ratio (0: N). Moreover, given that the substratum used for the high adhesive species and nutritious stress that is represented through the atomic ratio need to be considered, the copper alloy net is thought not to be suitable for abalone aquaculture.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.227-234
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• 2014

The effect of different feeding rate on the growth and survival rate of the abalone, Haliotis discus hannai, were investigated in marine net cage culture and indoor tank culture. Feeding rate is determined that was fed 5, 10, 15 and 20 percentage to abalone at body weight once daily : 5 daily feeding rate (DFR), 10DFR, 15DFR and 20DFR. After that, it was conducted to reared during thirteen month with two replicates in net-cage culture and indoor tank culture. In the growth performance of reared abalone (initial mean shell length $54.18{\pm}7.39mm$) in net cage culture, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth, as well as weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight of 20DFR were lower than those of different groups (P < 0.05). Also, survival rates of 20DFR was lower than those of different groups (P < 0.05). In the growth performance of reared abalone (initial mean shell length $49.70{\pm}2.28mm$) in indoor tank culture, that the ARG, DGR and SGR to the shell length and shell breadth, as well as WG, DWG and SWG to body weight of 5DFR and 10DFR were lower than those of different groups (P < 0.05). And also, survival rates of 20DFR was lower than those of different groups (P < 0.05). Therefore, these results is showed that the daily feeding rate for natural feed in net-cage culture and indoor tank culture should be to supply among 5-10 percents, taking into account growth, survival rate and economical efficiency.

• The Korean Journal of Malacology
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• v.30 no.3
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• pp.235-242
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• 2014

This study was conduct to investigate the effect of Intermediate culture types on the growth and survival rate of the abalone, Haliotis discus hannai, in net cage and indoor tank. Intermediate cultures were to determine there that was to setting at marine net cage culture (NCC) in net cage, floor culture (FC), net floor culture (NFC), double shelter culture (DSC) and indoor net cage culture (INCC) in indoor tank, in two replicate. In the growth performance of juvenile abalone reared through intermediate culture, that the absolute growth rate ($AGR_{SL}$, $AGR_{SB}$), daily growth rate ($DGR_{SL}$, $DGR_{SB}$), and specific growth rate ($SGR_{SL}$, $SGR_{SB}$) to the shell length $(_{SL})$ and shell breadth $(_{SB})$ of NCC were higher than those of different groups (P < 0.05). As weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight through intermediate culture types in indoor tank was not significant. Also that, survival rate among experimental groups of intermediate culture in indoor tank was not significant. Therefore, these results is showed that should to cultivate for net cage so that intermediate culture of juvenile abalone over 2 cm, accordingly research to effective progress of juvenile abalone intermediate culture in indoor tank be should from various reason as well as feed and rearing condition.

• Journal of Aquaculture
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• v.11 no.2
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• pp.133-140
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• 1998

A 20-week growth trial was conducted in flow-through aquarum system to investigate the practical dietary carbohydrate sources for juvenile abalone (Haliotis discus hannai). Four replicate grops of the abalone averaging 0.125g were fed one of eight diets containing 24.2% wheat flour (WF), 20% dextrin (DEX), 20% sucorse (SUC), 10% $^{\alpha}$-potato starch+10% $^{\beta}$-potato starch (ab-S), 15% $^{\alpha}$-potato starch (a-S15), 20% $^{\alpha}$-potato starch (a-S20), 25% $^{\alpha}$-potato starch (a-S25), or mixture (MIX) with practical ingredients such as soybean meal, corn gluten meal, cotton seed meal and heat flour. In addition, these formulated diets were compare with macroalgae such as dried sea mustard Undaria (D-SM) or dried sea tangle Laminaria(D-ST). Survival rate, weight gain, shell growth and soft body weight of abalone were not significantly affected by the different dietary carbohydrate sources (P>0.05), whereas those fed a-S15 diet were slightly low. These values of abalone fed D-ST were lowest (P<0.05), followed by those fed D-SM. Lipid contents of soft body from abalones fed a-S25, D-ST or D-SM were significantly lower than those of abalone fed other diets (P<0.05). These data indicate that abalone can equally utilize any carbohydrate sources used in this study.

• Journal of Life Science
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• v.24 no.7
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• pp.737-742
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• 2014

The objective of this study was to investigate the fatty acid composition of raw and dried abalone (Haliotis discus hannai) and to determine the effect of abalone extracts on cytotoxic activity and anti-oxidant properties. Dried abalone was extracted with acetone/methylene chloride (A+M) and methanol (MeOH), and the extracts were fractionated using n-hexane, 85% aq. methanol (MeOH), butanol (BuOH), and water. Cytotoxic activity against HT-29 cancer cell lines was determined using the 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay. Antioxidant activity was measured using a fluorescence sensitive dye, 2'-7' dichlorofluorescein-diacetate (DCFH-DA). The fatty acid composition of dried abalone was higher (22:6n-3) than that of raw abalone, and it had a lower percentage of 20:4n-6 than raw abalone. Analysis of cell viability showed that the crude extract treatments and fractions were cytotoxic, suppressing the growth of HT-29 cancer cell lines (p<0.05). The A+M extract showed a higher cytotoxic effect on the growth of HT-29 cells compared to the MeOH extract. Among the fractions, the 85% aq. MeOH fraction showed the strongest cytotoxicity against the growth of HT-29 cells. The highest activity in terms of scavenging reactive oxygen species (ROS) was likewise obtained with the use of 85% aq. MeOH. Our results suggest that the 85% aq. MeOH fraction has a potent inhibitory effect on the proliferation of human cancer cells.