• 융합정보논문지
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• 제11권1호
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• pp.128-135
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• 2021

바지락 발생배의 냉동보존을 위한 동해방지제의 효과를 규명하기 위하여4종의 보존액, dimethyl sulfoxide, ethylene glycol, glycerol 및 1,2-propanediol을 사용하여 발생배의 생존율을 조사한 결과로, 생존율의 범위는 0-64.3%였고, 대조구의 생존율은 82.3%을 보였다. 발생배의 냉동보존을 위한 프로그래 동결 과정은 최초 25℃에서 10분 동안 유지하다가 자동 냉동보존 프로그램 장치에 의하여 -12℃까지 분당 -1℃씩 조정하였으며 -35℃까지는 분당 -2℃씩 하강시켜 액체 질소통에 스트로우를 넣어 해동 후 관찰한 결과, 바지락 생존율은 DMSO(dimethyl sulfoxide) 2.0M 실험구에서 64.3%로 가장 좋은 결과를 보였다.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2000년도 춘계수산관련학회 공동학술대회발표요지집
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• pp.497-498
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• 2000

The venus clam, Ruditapes philippinarum, is an aquaculture shellfish mainly distributed in an intertidal zone of East Asia including Korea, China and Japan. The morphological variation of this species is great. In fact, two of the most popular markers used in molecular evolution, mitochondrial DNA (mtDNA) and nuclear ribosomal DNA (rDNA), have quite different properties, which could translate into different consequences of mutation, drift, migration and selection on patterns of geographical variation and molecular divergence. (omitted)

• 한국패류학회지
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• 제23권1호
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• pp.25-30
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• 2007

양식생물의 최적생산을 위해서는 적극적 관리 외에도 환경 개선과 지속적으로 최대생산을 위하여 수산자원학적 관리방안도 함께 강구되어야 한다. 따라서 양식장의 생산성 향상을 위하여 어느 시기에 어느 정도의 사이즈의 생물을 선택적으로 채취하여야 할 것인가는 양식생산 측면에서 아주 중요한 문제가 될 수 있다. 이를 위하여 통영시 한산면 진두연안의 바지락양식장의 양성중인 바지락자원의 자원학적 특성치로부터 가입당 생산량 모델을 구현하였고, 이 모델을 통해 현재의 양식생물 이용현황을 파악하고자 하였다. 현재의 어업형태에 따른 $t_c$와 F를 적용하면, 가입당 생산량은 3.46 g에 해당하였지만, $t_c$의 경우 3.48 세까지, F의 경우 0.9295/yr까지 증가시키면 약 5% (3.63 g)의 생산증대효과를 볼 수 있는 것으로 예상되었다. 그러나 채취시기를 연장함에 따른 사육소요기간의 장기화 및 자연사망계수의 변동 가능성을 고려한다면 현재의 어업행위가 가장 적합한 것으로 판단된다.

• Fisheries and Aquatic Sciences
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• 제12권4호
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• pp.324-330
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• 2009

Cadmium (Cd) accumulation and elimination were assessed in the tissues of the clam R. philippinarum at four experimental concentrations (control, 10, 20, 100, and $200\;{\mu}g/L$) over an exposure period of 2 weeks and an elimination period of 1 week. Cd accumulated in the digestive gland, gill, and residual clam tissues, and accumulation increased with time of exposure and concentration (100 and $200\;{\mu}g/L$). After 2 weeks of Cd exposure, the order of Cd accumulation in tissues was gill > digestive gland > residual tissues. An inverse relationship was observed between concentration factor (CF) and exposure level, but the CF showed an increase with exposure time. During the depuration period, Cd concentrations in the digestive gland, gill, and residual tissues decreased immediately on the cessation of exposure, except in individuals at the $200\;{\mu}g/L$ concentration. The Cd elimination rate from tissues decreased in the order of digestive gland > gill > residual tissues during the depuration period.

• 한국패류학회지
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• 제28권2호
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• pp.109-116
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• 2012

In order to understand the effect of introduction of oyster rack culture on natural short-necked clam, Ruditapes philippinarum, stock, we investigated the status of natural clam stock prior to introduction of oyster rack culture at Yeongheung Coast of Wando Island. The growth equation of the clam was estimated as: $L_t=61.46{\cdot}(1-e^{-0.172(t+0.155)})$ from ring radius composition of shell. Instantaneous coefficient of total mortality and natural mortality were calculated as: 2.4087/year and 0.478/year, respectively. The age at first capture was estimated to be 2.55 year. The total biomass was estimated to 3.23 ton in the bed (0.8 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit (Y/R) was corresponded to $114.7individuals/m^2$ and $92.0g/m^2$, respectively. Maximum sustainable yield (MSY) was estimated 0.77 ton/year which was close to annual catches, 0.74 ton/year, in the area.

• Fisheries and Aquatic Sciences
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• 제4권4호
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• pp.208-218
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• 2001

We have investigated the gonad index (GI), gonadal development, reproductive cycle, first sexual maturity, sex ratio, the number of spawned eggs and spawning frequency of the Manila clam, Ruditapes philippinarum. Samples were collected from the intertidal zone of Komso Bay, Korea from January to December in 1999. Monthly changes in the gonad index (GI) and condition index showed a similar pattern in the reproductive cycle. The spawning period was once a year between early June and early October, there was a spawning peak between July and August when seawater temperature was over $20^{\circ}C$. The reproductive cycle of this species can be categorized into five successive stages; early active (February to March), late active (April to May), ripe (April to August), partially spawned (June to October), and spent/inactive stage (August to March). Percentages of first sexual maturity of female and male clams of l5.1-20.0mm in shell length were $56.3\%$ and $60.0\%$, respectively, and $100\%$ for the clams >25. mm. The sex ratio of individuals >15.1 mm in shell length was about 1:1 $(\chi^2= 0.02,\;p>0.05)$. Number of the eggs released from each clam by the induction increased as the size of clam in terms of shell length increased. Mean number of the eggs from the second induction of the spawning was $75.35-84.30\%$ $(average\;79.81\%)$ of the number of the eggs released in the first spawning. Our data indicated that R. philippinarum in Komso Bay has one major spawning peak with over two minor spawning, and the interval of each spawning was estimated to be approximately 15-17 (average 16.5) days.

• 한국패류학회지
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• 제20권2호
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• pp.171-181
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• 2004

백합 과 (family Veneridae) 패류, Saxidomus purpuratus (개조개), Meretrix lusoria (백합), Meretrix petechialis (말백합), Pitar sulfureum (쇠백합), Ruditapes philippinarum (바지락), Ruditapes variegata (애기바지락), Gomphina aequilatera (대복), Cyclina sinensis (가무락), Dosinella corrugata (주름떡조개) 등 9종과 outgroup으로 Corbicula fluminea (재첩) 를 이용하여 primer로 017 (5'-GGTCAACAAATCATAAAGATATTGG-3'), 018 (5'-TAAACTTCAGGGTGACCAAAAAATCA-3') 를 사용하여 부분적인 mitochondrial cytochrome oxidaxe subunit Ⅰ 유전자에 대한 염기서열을 얻었다. 이밖에도 GenBank에 보고된 Meretrix lamarki, Ruditapes philippinarum, Mercenaria mercenaria 등 3 종에 대한 mCOI 염기서열을 얻어서 maximum parsimony와 neighbor-joining방법으로 분석을 시행하였다. samarangiinae에 속한 3종의 패류 (Ruditapes philippinarum, Ruditapes variegata, Gomphina aequilatera)는 단계통을 보였다. Meretrix lusoria와 M. petechialis는 동일 조상을 갖고 있었으며 Pitarinae에 속한 Saxidomus purpuratus와 CYclinae에 속한 Cyclina sinensis와 동일 조상을 갖는 종들로 나타났다. Pitarinae의 Pitar sulfureum 과 Saxidomus purpuratus는 각기 다른 분지를 이루고 있었다.

• 한국수산과학회지
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• 제49권6호
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• pp.800-806
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• 2016

In total, 151 Escherichia coli isolates from Ruditapes philippinarum in Gomso Bay were analyzed for their susceptibility to 18 different antimicrobial agents and for genes associated with virulence. For virulence genes, each strain of the isolates was positive for the enterotoxigenic E. coli (ETEC)-specific heat-stable toxin (estA), enteroinvasive E. coli (EIEC)-specific invasion-associated locus (iaa) gene and enteropathogenic E. coli (EPEC)-specific attaching and effacing (eae) gene. According to a disk diffusion susceptibility test, resistance to ampicillin was most prevalent (23.2%), followed by resistance to amoxicillin (22.5%), ticarcillin (20.5%), tetracycline (18.5%), nalidixic acid (12.6%), ciprofloxacin (10.6%), streptomycin (9.9%), and chloramphenicol (6.6%). More than 35.8% of the isolates were resistant to at least one antimicrobial agent, and 19.9% were resistant to four or more classes of antimicrobials; these were consequently defined as multidrug resistant. Minimum inhibitory concentration (MIC) ranges for the antimicrobial resistance of the 15 different antimicrobial agents of 54 E. coli strains were confirmed by varying the concentrations from $32-2,048{\mu}g/mL$. Overall, these results not only provide novel insights into the necessity for seawater and R. philippinarum sanitation in Gomso Bay but they also help to reduce the risk of contamination by antimicrobial-resistant bacteria.

• 한국패류학회지
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• 제26권3호
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• pp.245-254
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• 2010

For the studies of germ cell development and maturation in the ovary, the gametogenic cycle and the number of spawning seasons per year in female Ruditapes philippinarum were investigated by quantitative statistical analysis using an Image Analyzer System. Compared with the results by qualitative and quantitative analyses, monthly variations in female gonad indice by qualitative histological analysis showed a pattern similar to that of the female gametogenic cycle calculated by quantitative statistical analysis. The number of spawning seasons occurred once per year, from June to October. In quantitative statistical analysis using an image analyzer system, monthly changes in the portions (%) of the ovary area to total tissue areas in females increased in March and reached a maximum in May, and then showed a rapid decrease from June to October when spawning occurred. And also monthly changes in portions (%) of follicle areas to the ovary area and in portions of oocyte areas to ovarian tissue areas in females began to increase in March and reached a maximum in May, and then. rapidly dropped from June to October when spawnig occurred. From these data, it is apparent that the number of spawning seasons occurred once per year, from June to October. Monthly changes in the number of the oocyte per $mm^2$ and in mean diameter of the oocyte in captured image which were calculated for each female slide showed a maximum in May and reached the minimum from December to February. Therefore, female R. philippinarum showed a unimodal gametogenic cycle during the year.

• 한국발생생물학회지:발생과생식
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• 제9권2호
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• pp.123-134
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• 2005

암컷 바지락, Ruditapes philippinarum의 난 형성과정 중 생식세포 발달과 난소 성숙 및 군 성숙도를 세포 및 조직학적 관찰에 의해 조사하였다. 바지락은 자웅이체이다. 난황 형성 과정 중 골지복합체, 글리코겐 입자들과 미토콘드리아들은 초기 난황 형성 단계의 난모 세포질 내에서 지방적 및 지방 과립 형성에 관여한다. 후기 난황 형성 단계 난모 세포질 내의 피질 과립, 조면 소포체 및 미토콘드리아들은 세포질 내에서 단백질성 난황 과립의 형성에 관여하였다. 이 시기에 생식상피 내의 외인성 지질 과립상 물질들과 글리코겐 입자들이 난황막의 미세 융모를 통해서 난모 세포질 내로 통과해 들어간다. 산란기는 6월 초에서 10월 초 사이로 연중 한 번이었으며, 주 산란은 해수 수온이 대략 $20^{\circ}C$인 7월과 8월 사이에 일어났다. 본 종의 생식주기는 초기 활성기($1{\sim}3$월), 후기 활성기($2{\sim}5$월), 완숙기($4{\sim}8$월), 부분 산란기($5{\sim}10$월), 퇴화 및 비활성기($8{\sim}2$월)의 연속적인 5단계로 구분되었다. 각장 $15.1{\sim}20.0\;mm$인 암컷 조개의 군 성숙도 비율(%)은 52.6%(군 성숙도 50%는 각장 17.83mm)이었고, 각장 25.1mm 이상인 조개는 100%의 군 성숙도를 보였다.