• Journal of Aquaculture
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• v.16 no.4
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• pp.223-228
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• 2003

An exfoliation, the detachment of juvenile abalones from a culture substrate, is essential for selection and population density control in abalone culture. Physical instruments and anesthetics are currently available for the exfoliation but the latter is regarded as more effective in reducing physical damage to the animals. In the present study, urea ($Co(NH_2)_2$), a chemical fertilizer, was selected as a anesthetic, and its optimal concentration and sea water temperature for exfoliation of Haliotis discus were determined in order to develop an exfoliation technique which is more economical and effective. A 97% cumulated exfoliation rate was observed within 3 min at all temperatures observed when the concentration rate of urea was 9∼15%. This range of urea concentration can be ideal for both exfoliation and recovery. Also it was found that the higher concentration of urea and temperature the higher exfoliation rate, however, these conditions reduced the recovery rates of the animals tested. These results could indicate that urea is a good tool for exfoliation of various species of young abalones, and urea could substitute for all techniques and anesthetics methods currently available for abalone exfoliation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.4
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• pp.435-442
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• 1995

The abalone shell (Haliotis) is one of the most important resources for the coastal fisheries and it is popular as an aquacultural species. Proper cultivating grounds for mid-term nursery of abalone spats are required before releasing them. It is difficult for us to find good enough aquacultural grounds to rear abalone spats to 20"30mm of shell length. Therefore, we need to study a practical and effective new type of aquacultural device for the nursing of abalone spats by using open sea areas. We can find this kind of studies from 'Marine aya No. 1' of Japan, Though they focused on the easy operation, safe working and low operating cost, it involves so much initial cost that it is difficult for us to justify such expenditure. However, with a modified small buoy system, this submersible facility needs only a horizontal frame to fulfill its essential function and the vortical part can be removed. The working boat equipped with a pump can operate this facility to keep it submerged or floated. This paper deals with the possibility of this submersible fishery facility for the mid term nursing of abalone spats in the open sea. A small version of this system to ensure low initial cost is suggested and wave and current forces were calculated for the estimation of the weight of the mooring anchor.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.98-98
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• 2003

최근 고부가가치의 산업으로 자리매김한 참전복, Haliotis discus hannai Ino 인공종묘생산시 생산성 향상을 위해, 참전복 사육수조의 파판에 부착 생육하는 Cocconeis sp., Nitzschia sp., Navicula sp., Bacillaria sp., Licmophora sp. 5종을 순수분리한 후 대량배양하여 각 종별 규조류와 자연발생된 혼합규조류에 대한 전복유생의 부착율, 초기치패의 성장 및 생존등을 비교분석 하였다. 5종의 부착규조류의 20$\ell$ 배양은 약 2주간 실시되었는데 초기접종농도는 각각 20만세포/$m\ell$ 였으며 가장 빠른 성장을 보인 종은 Cocconeis sp.와 Navicula sp.로 접종 12일후에 각각 128만세포/$m\ell$와 110만세포/$m\ell$로 높게 나타났다. 그리고 Licmophora sp.는 69 만세포/$m\ell$로 가장 저조한 성장을 보였다. 유생의 부착율은 Cocconeis sp. 배양 시험구에서 43.1%로 가장 높았으며, Licmophora sp.는 16.3%로 대조구에 비해 현저히 낮은 값을 나타냈다(P<0.05). 치패의 일간성장율은 Navicula sp.에서 64.1 $\mu$m로 가장 높았으며, Licmophora sp.는 22.4 $\mu$m로 대조구에 비해 월등히 뒤지는 것으로 나타났다. 치패의 생존율은 Navicula sp.에서 62.0%로 가장 높은 값을 나타내었으며 (P<0.05), Cocconeis sp. 와 Nitzschia sp.는 각각 60.5%, 59.2%로 대조구의 48.8% 보다 높은 생존율을 보였다 (P<0.05). 본 시험의 결과는 먹이효율이 뛰어난 특정 부착성 규조를 전복 종묘생산에 이용하므로써 전복 유생의 부착율, 치패의 생존 및 생장율 향상을 가져올 수 있다는 것을 보여준다.

• Journal of Aquaculture
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• v.11 no.4
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• pp.505-512
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• 1998

This study was conducted to investigate the effects of three different formulated diets and macroalgae(Undaria) on growth and body comoposition among juvenile Haliotis discus, H. sieboldii and H. discus hannail. Three replicate groups among the three species abalones average weighing 0.31g were fed one of one experimental diet, two commercial diets and Undaria for 9 weeks. The three formulated diets produced significantly (P<0.05) greated body and shell growth than Undaria within same abalone species. Survival rates (97~99%) of H. discus and H. sieboldii were higher than that (74~77%) of H. discus hannai. Whereas different diets had no significantly (P>0.05) distincitive effect on survival within each three different abalone species. Moisture of abalone soft body in final stage reduced compared to those of abalone in initial stage in H. discus and H. discus hannai. Regardless of diet, abalone soft body revealed significantly (P<0.05) increased protein and decreased ash at the end of feeding trial in all three abalone species. This study indicate that all three different formulated diets used in this experiment could be a practical diet in three abalone species.

• Journal of Aquaculture
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• v.9 no.1
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• pp.65-71
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• 1996

To estimate the variation of food organisms on the corrugated PVC sheets, we analysed the chlorophyll a and. pheopigments of the benthic microalgae on the sheets from the oyster culture ponds. We estimated the standing crops as the amounts of chlorophyll a, and the physiological state of cells as the pheopigments level in the benthic microalgae. The amount of chlorophyll a was increased by immersion time in winter but the peak was observed every two weeks in summer, while the ratio of pheopigments was highest in summer but the low level was observed in spring and autumn. These seasonal variation were well coincided with the natural spawning season and the good microalgae nutritional valance.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.622-623
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• 2001

전복류는 세계적으로 100여종으로 알려져 있고, 이중 어획 대상이 되는 대형종은 20여종으로서 주로 온대수역에서 많이 생산되고 있다. 우리나라에 서식하는 전복류는 소형종인 오분자기(Haliotis diversicolor supertexta)를 비롯하여 난류계의 대형종인 말전복(H. gigantea), 까막전복(H. discus), 시볼트 전복(H. sieboldii) 그리고, 한류계인 참전복(H. discus hannai)의 5종이 알려져 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.522-523
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• 2000

우리나라에서 건강식품으로 널리 알려져 있는 참전복은 불로장수의 식품으로 널리 애용되고 있을 뿐만 아니라 발암억제 물질인 paolin을 함유하고 있어, 세계적으로 상품가치가 인정되고 있다. 이러한 중요성에도 불구하고 참전복 부착치패의 성장 및 생존율 제고는 아직까지도 해결되어야 할 문제로 남아 있는 실정이다. 참전복 부착치패의 먹이선택성 및 유인성에 관한 기존의 연구를 보면 Viana et al. (1994)은 평균 각장 4.2 cm인 치패를 이용하여 배합사료의 9가지 원료에 대한 유연성을, Harada and Kawasaki (1982)는 각장 2.4 cm 이상인 치패를 대상으로 해조류 3종(미역, 톳, 파래)의 유인효과에 관하여 보고하였다. 그러나 이와 같은 보고들은 전복 종묘생산 현장에서 보다 빠른 시기에 박리하여 해조로 먹이 전환을 하기 위한 노력과는 어느 정도의 거리가 있다고 판단된다. 따라서 본 연구에 있어서는 평균 각장 5.0$\pm$1.0 mm인 치패를 박리하여 Navicula spp., 해조 2종(다시마, 파래) 및 자체 제조한 사료를 공급하여 먹이별 유인효과를 관찰하였다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.304-305
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• 1998

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.119-125
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• 2016

The present study aimed to understand the effects of a ${\beta}$-glucan-added abalone feed (Immuneglu$^{TM}$) on the immune parameters, survival rate, and anti-bacterial activity of the abalone Nordotis discus hannai. During the study, spat and adult abalones were fed 0, 0.1, and 1% of Immuneglu$^{TM}$ mixed with artificial feed for 2 weeks, and their immune parameters, survival rate, and anti-bacterial activity were measured. The results showed that abalones fed on Immuneglu$^{TM}$-added feed showed a higher phagocytic rate, survival rate, and anti-bacterial activity against Vibrio alginolyticus, than those with the control treatment. In addition, the nitric oxide concentration, which indicates an inflammatory response, increased in the treatment group. Our study suggests that Immuneglu$^{TM}$ might be a useful additive for increasing the immunity and survival rates of abalones during mass culture.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.157-163
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• 2010

This study was carried out to investigate the toxic effect of WSF (Water Soluble Fraction) on development time, development rate, attachment rate, survival rate and growth of the larvae during the early life stage of the abalone, Haliotis discus hannai. Also, observed effect of water temperature on the survival rate and histological change of gill in the early young shell. In the abalone, it takes around 12 hours in all experimental groups. Development and attachment rate of the abalone significantly lower more than 0.4 mg/L WSF compared to control group (P < 0.05). Survival rate of abalone larva and spot was significantly lower more than 0.4 mg/L and 2.4 mg/L WSF compared to control group, respectively (P < 0.05). Shell growth of the abalone were significantly lower more than 2.4 mg/L WSF compared control group (P < 0.05). Survival rate lower more than $25^{\circ}C$ exposure group compared water temperature $17^{\circ}C$ exposure group in the early young shell. The gill of abalone exposed water temperature $17^{\circ}C$ and $25^{\circ}C$ was showed atrophy of nucleus and breakdown of the filament, vacuolation of filament epithelial cell.