• 한국해양환경ㆍ에너지학회지
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• 제16권2호
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• pp.138-142
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• 2013

저염분에 따른 양식생물의 피해를 줄이기 위한 조기경보 방안으로 염분에 따른 굴(Crassostrea gigas) 패각운동 특성을 홀 소자를 이용하여 측정하는 생물모니터링시스템의 적용 가능성을 조사하였다. 염분농도 27 psu에서 굴의 패각운동은 평균 10-15 mm 정도의 개각상태를 유지하다가, 비교적 빠른 폐각상태를 지시하는 큰 파형이 보였으며, 다시 개각상태로 돌아가나, 그 속도는 폐각상태로 진행되는 속도보다 느리게 나타났다. 20 psu까지 저염분의 농도에서는 27 psu의 패각 운동과 큰 변화가 없었다. 하지만 17 psu 이하의 염분농도부터 이상 패각운동이 지시되었으며, 10 psu에서는 패각운동이 없이 폐각상태를 유지하였다. 이와 같은 생물모니터링시스템을 패류 양식에 활용하여 해양환경의 이상변동을 신속히 감지할 수 있다면, 어업피해를 감소시킬 활동으로 연결될 것으로 기대된다.

• 한국수산과학회지
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• 제1권1호
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• pp.45-49
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• 1968

인천산 굴, Crassostrea gigas, 담륜자의 치사율에 미치는 염도, 온도, 그리고 혼영도의 영향에 관하여 연구하였다. 1. 정상해수로부터 저염도 혹은 고염도인 해수로 옮겨진 굴의 탐륜자는 차차 생명력을 잃었다. 담륜자의 치사율은 각각 저염도인 15 ppt에서 $46\%$이었고 고염도인 35ppt에서는 $47\%$이었다. 2. 고온도인 $40^{\circ}C$ 이상은 정상해수중의 담륜자에 대하여 치사요인이 있고, 특히 $45^{\circ}C$에서는 30분이내에 모두 사망하였다. 그리나 저온은 고온에 비하여 그렇게 치사적인 요인이 아니었다. 각 온도의 30분과 1시간 처리에서 나타난 두 치사곡선간의 차이는 통계학적으로 유의하지 않았다 (P>0.05). 3. 농혼탁도 ($1\%$)는 담륜자의 치사율에 대하여 처리후 단시간내에는 별로 영향을 주지 않았다.

• 한국수산과학회지
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• 제55권3호
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• pp.249-256
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• 2022

This study was conducted to investigate the sensory and nutritional properties of oyster Crassostrea gigas gratin with cream sauce (OG-CS) and to compare with commercial seafood gratin with cheese (control). The proximate composition (%, w/w) of OG-CS was 61.8 of moisture, 8.5 of protein, 16.1 of lipid, 1.2 of ash, 12.4 of carbohydrate, of which the moisture was lower and protein, lipid, ash, and carbohydrate values were higher than those of the control. Based on the results of sensory evaluation by panel members, OG-CS was superior to the control for all parameters, including taste, flavor, texture, nutrition, and overall acceptance. The total amino acid content of OG-CS (7.33 g/100 g) was higher than that of the control (5.20 g/100 g). The major amino acids of OG-CS were glutamic acid (18.8%), proline (9.8%), and leucine (8.2%). The mineral levels of OG-CS were 134.5 mg/100 g for calcium, 164.9 mg/100 g for potassium, 0.8 mg/100 g for iron, and 4.5 mg/100 g for zinc, which were all higher than those of the control. The major fatty acids of OG-CS were 12:0 (28.2%), 16:0 (24.9%), and 14:0 (13.6%), which were the same as those in the control.

• 한국어병학회지
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• 제19권3호
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• pp.243-251
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• 2006

패류의 방어시스템에서 순환 haemocytes는 중요하다. 참굴, Crassostrea gigas haemocytes의 형태적 특징을 이해하기 위해서 광학현미경적 특징과 전자현미경적 특징을 관찰하였다. 그 결과 4종류의 haemoctyes type을 확인하였다: type Ⅰ small hyalinocytes, type Ⅱ large hyalinocytes, type Ⅲ large granulocytes, type Ⅳ small granulocytes. 또한, 면역세포학적 방법으로 haemocytes의 alkaline phosphatase (ALP), acid phosphatase (ACP), peroxidase (POD), α-naphthyl acetate esterase, β-glucuronidase, PAS, sudan black B와 oil red O의 활성을 조사하였다. 그 결과, 조사한 모든 효소의 활성이 granulocytes에서 hyalinocytes에 비하여 높게 나타났다.Haemoctyes와 Vibrio FKC를 incubation 후 식균지수와 식균율을 조사하였다. 그 결과, 식균지수와 식균율은 배양 15분째부터 증가하여 120분까지 높게 나타났다. 또한, ALP, ACP, α-naphthyl acetate esterase와 β-glcuronidase의 효소활성도 대조구에 비하여 높게 나타나 이와 같은 효소는 참굴의 식작용에 중요한 역할을 하는 것으로 생각된다.

• Fisheries and Aquatic Sciences
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• 제5권3호
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• pp.191-199
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• 2002

Pacific oysters Crassostrea gigas (Thunberg) were collected on April, 1999 and March­September, 2000 from Goseung Bay along the southern coast of Korea. The oysters tested cp;;ected from a depth of 0.5-2 m in which they cultured by a long line hanging method. The oxygen consumption rates (OCR) of oysters held under constant temperature and darkness (CC), were determined using an automatic intermittent-flow-respirometer (AIFR). Depending on holding periods after oyster collection, the experiments were divided into two groups: Group 7-d (held to ambient temperature for ca. 7 days) and Group 2l-d (held to ambient temperature for ca. 21 days). The OCR for Group 7-d single oyster displayed two peaks every day under CC, while Group 2l-d single oyster showed one peak every day. It is likely that the rhythmic patterns 02.6-12.8 hours) of the OCR in the Group 7-d single oyster may have been influenced by tidal currents at the sampling site. The rhythmic patterns (24.3-24.7 hours) in the Group 2l-d single oyster may have been shifted from two peaks to one peak each day under CC. The present study concludes that the OCR rhythm of wild oysters in nature is governed by two lunar-day clocks (24.8 hours); one driving one peak and the other driving the second peak. When oysters are subjected to the long-term CC conditions, one of the two-clock systems is depressed or only intermittently becomes active. Jpwever. the OCR rhythms by two to three oysters occurred arrhythmic patterns during the experiments and exhibited some evidence of weak rhythmicity of compared to those of a single oyster. It could be partly due to differences group effects.

• 한국패류학회지
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• 제30권3호
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• pp.249-258
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• 2014

Phytoplankton species composition and ecological index (diversity, evenness, richness and dominance) were analysed from April 2013 to March 2014 at 10 stations of cupped oyster, Crassostrea gigas culture area in Iwon coast, Korea. Seasonal and positional variation of phytoplankton standing crops, biomass, dominant species and water quality were distinctively different according to occasionally inflow of Iwon dam reservoired water. The composition of phytoplankton species were Bacillariophyceae 98, Dinophycease 22, Chlorophycease 13, Cyanophyceae 8, Silicofalgellate 4, Euglenophyceae 2, Cryptophyceae 1 species. The most dominant species was Bacillariophyceae as 64.0%. The highest biomass of phytoplankton recorded in September as $40,910{\times}10^3$ cell/L at the station 1, near from inland water inflow area. Ecological indices (diversity, richness, evenness, and dominance index), used for structural change of phytoplankton community and water quality (temperature, dissolved oxygen, salinity) showed difference of spatiotemporal property also.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.135-141
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• 1999

In order to investigate the composition of extractive nitrogenous components in the diploid and the triploid oysters, Crassostrea gigas, cultured at the south coast of Korea, the whole edible part (whole body) was analyzed into extractive nitrogen, free amino acids, oligopeptides, ATP and its related compounds, quaternary ammonium bases, and guanidino compounds using specimens collected from April to May of 1992. The major free amino acids in the diploid and the triploid were taurine, proline, alanine, glycine, glutamic acid hypotaurine, glutamine, arginine, aspartic acid, and $\beta-alanine$. There was no conspicuous difference in the constituents of free amino acids between the diploid and the triploid. A lot of hypotaurine was detected in the diploid and the triploid of oyster and the contents of them were 107 mg and 123 mg/100g, respectively. The compounds, glycinebetaine, homarine and trigonelline were found in both the diploid and the triploid. Among them, glycinebetaine was the most prominent in all the samples. The amount of protein, glycogen, extractive nitrogen, oligopeptides, ATP and its related compounds, and free amino acids in the triploid was higher than that of the diploid (p<0.10)

• 한국양식학회지
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• 제20권4호
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• pp.205-211
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• 2007

Stress-inducible proteins may function in part as molecular chaperones, protecting cells from damage due to various stresses and helping to maintain homeostasis. We examined the mRNA expression patterns of a 68-kDa heat shock protein (HSP68) and 78-kDa glucose-regulated protein (GRP78) in relation to physiological changes in Pacific oyster Crassostrea gigas under osmotic stress. Expression of HSP68 and GRP78 mRNA in the gill significantly increased until 48 h in a hypersaline environment (HRE) and 72 h in a hyposaline environment (HOE), and then decreased. Osmolality and the concentrations of $Na^+$, $Cl^-$, and $Ca^{2+}$ in the hemolymph of HRE oysters significantly increased until 72 h (the highest value) and then gradually decreased; in HOE oysters, these values significantly decreased until 72 h (the lowest value), and then increased. These results suggest that osmolality and $Na^+$, $Cl^-$, and $Ca^{2+}$ concentrations were stabilized by HSP68 and GRP78, and indicate that these two stress-induced proteins play an important role in regulating the metabolism and protecting the cells of the Pacific oysters exposed to salinity changes.

• 한국수산과학회지
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• 제51권5호
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• pp.491-498
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• 2018

The objective of this study was to investigate the composition of canned oyster Crassotrea gigas in white sauce (CO-WS). The proximate composition of CO-WS was 74.1% water, 10.4% crude protein, 4.9% crude lipid, and 3.1% ash. The energy converted based on these percentages was 112.2 kcal/100 g, while the salinity was 1.1 g/100 g. In a taste-intensity test using an electronic tongue, the CO-WS showed higher umami taste intensity than the control (canned oyster in commercial white sauce), whereas the intensities of the other tastes (salty, sour, bitter, and sweet) were lower. Because the odor intensity was low, CO-WS was considered to have a relatively weak odor and showed no difference in hardness compared to the control. Sensory evaluation of CO-WS by a panel yielded higher scores for appearance, taste, and texture, and a lower score for flavor compared to the control. The total amino acid content of CO-WS was 8.91 g/100 g, and its major amino acids were aspartic acid, glutamic acid, and leucine. With respect to mineral content, CO-WS had higher calcium and lower zinc contents than the control. These results suggest that CO-WS has excellent nutritional value.

• 한국어병학회지
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• 제14권2호
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• pp.103-105
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• 2001

The effect of opsonization of zymosan with serum on the repiratory burst of haemocytes isolated from the Pacific oyster Crassostrea gigas was investigated. The reactive oxygen species (ROS) produced by the respiratory burst of haemocytes in response to the opsonized or unopsonized zymosan were measured using chemiluminescence (CL). The CL values were increased according to the increment of haemocyte number. The degree of CL amplification by increase of haemocytes from $0.1{\times}10^6$ to $0.5{\times}10^6$ cells/ml was 3-5 times, but comparatively low amplification was elicited by increase of haemocytes from $0.5{\times}10^6$ to $1{\times}10^6$ cells/ml. Chemiluminescences produced by the haemocytes in response to the zymosan opsonized with oyster serum were considerably higher than the CL produced by the haemocytes in response to the unopsonized zymosan.