• 농촌의학ㆍ지역보건
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• 제15권2호
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• pp.89-96
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• 1990

The results of infection state of anisakid larvae and parasitic helminths in salmon and sea-trout which caught from Taep'o port. Kang-won do were as follows. 1) From twelve specimens of sea-trout. 122 individuals of anisakid larvae were found and mean infection number of anisakid larvae per individual sea-trout was 10.17. 2) From total extracted anisakid larvae from sea-trout. 37 larvae(30.3%) were found in the muscle. This percentage was lower than that of salmon. but higher than that of other sea-fishes. 3) The taxonomic list of parasitic helminths which found in salmon and sea-trout was as follows. Class Trematoda Family Hemiuridae l. Brachyphallus crenatus(Rudolphi. 1802) 2. Lecithaster salmonis Yamaguti. 1934 Class Cestoda Family Phllobothriidae 3. Pelichnibothrium speciosum Monticelli, 1889-larval form Family Tentacuariidae 4. Tentacularia sp. - larval form 4) Among those 4 species of helminths. B.crenatus. L.salmonis, P.speciosum were the first recording species in Korea.

• 한국수산과학회지
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• 제29권2호
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• pp.208-229
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• 1996

한국산 연어속에 속하는 연어, 산천어 및 무지개송어 3종의 골격학적 비교 연구를 하였다. 연어속 어류인 연어, 산천어, 무지개송어의 골격을 비교한 결과 두개골과 현수골의 형태나 결합 형태에서 3종간 차이를 나타내었다. 두부 골격중에서는 인설골, 상사골, 부설골, 서골의 형태에서 종간 차이가 뚜렸하였고 계통 분류학적 특징을 잘 나타내었다. 연어의 인설골은 산천어, 무지개 송어에 비하여 가늘고 길며, 끝이 뾰족한 특징을 가졌다. 상사골은 연어가 거의 정삼각형의 모양을 가지고 있으나 산천어나 무지개송어는 가늘고 길며 날개를 가진 형태였다. 본 연구에 나타난 골격 형질 분석 결과 알려져 있는 분류 형질외에 부설골의 형태, 전새개골, 설악골의 형태 및 미추골수 등이 새로운 분류 형질로 나타났으며, 산천어는 연어와 무지개송어의 중간 형질을 가지고 있는 종으로 나타났다.

• 한국수산과학회지
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• 제41권5호
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• pp.343-345
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• 2008

This study determined the optimum feeding frequency for the growth of juvenile cherry salmon (Oncorhynchus masou). Triplicate groups of fish (initial mean weight 19.1 g) were fed extruded pellets at four feeding frequencies for 50 days: once every 2 days, once a day, twice a day, and three times a day. The mean water temperature during the feeding trial was $17.9{\pm}1.59^{\circ}C$. The survival of all groups was 100%. The final fork length of fish fed twice a day was significantly greater than that of the other groups (P<0.05). The weight gain of fish fed two and three times daily was significantly greater than that of fish fed once a day or every 2 days (P<0.05). The daily feed intake increased significantly with feeding frequency (P<0.05), but there was no significant difference in the weight gain of fish fed two or three times a day. The feed efficiency of fish fed once every 2 days was highest (P<0.05), and the feed efficiency of fish fed two or three times a day was significantly higher than that of fish fed once a day (P<0.05). The results of this study indicated that the optimum feeding frequency for the growth of juvenile cherry salmon is twice a day, while the feeding efficiency of fish fed once every 2 days was best.

• 환경생물
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• 제22권1호
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• pp.111-119
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• 2004

2002년 12월부터 2003년 9월까지 파로호의 어류상 및 어류군집을 조사한 결과는 다음과 같다. 조사된 어류는 총 12과 45종이었다. 한국고유종은 H. mylodon, A. yanatsutae, C. herzi 등 15종 (33.33％)이었다. 우점종은 Z. platypus (72.41％), 아우점종은 H. labeo (9.75％)였고 우세종은 O. uncirostris amurensis (5.98％), Z. temmincki (2.42％), R. brunneus (2.01％), H. olidus (0.88％) 등이었다. 채집된 어종들의 생체량은 Z. platypus 82,863.15g, H. labeo 32,942.63 g, O. uncirostris amurensis 27,482.39 g, C. carpio 6,502.87 g, A. japonica 3,022.15 g,S. scherzeri 2,711.05g의 순으로 나타났다. 파로호에서 확인된 도입종은 A.japonica, H. eigenmanni, H. olidus, O. masou masou, C. urotaenius, R. giurinus, C. carpio (Israeli type), C. cuvieri, M. salmoides, L. macrochirus의 10종이었다. 이 중 C. carpio (Israeli type), C. cuvieri, M. salmoides, L. macrochirus는 국외종이며 A. japonica, H. eigenmanni, H. olidus, O. masou masou, C. urotaenius, R. giurinus는 국내 다른 하천으로부터 도입된 종이다.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.176-181
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• 1999

The variations of gene expression and pituitary contents of GTH subunits during the ovarian development of masu salmon, Oncorhynchus masou, were investigated. The pituitary GTHs contents was measured by radioimmunoassays (RIAs) using purified GTH subunits and their antibodies. Pituitary contents of GTH $I\beta$ gradually increased from April through August, and reached the maximum in October. On the other hand, pituitary contents of GTH $II\beta$ remained low until August, but they rapidly increased in October. Total RNAs were prepared from pooled pituitaries and the GTH subunits mRNA in pituitaries was quantified by Northern blot hybridization using masu salmon cDNA probes for each GTH subunit. GTH $I\beta$ mRNA level increased with the progression of ovarian maturity. However, GTH $II\beta$ mRNA was detected only at a more advanced stage, and were extremly high at ovulation. A high levels for GTH a mRNA was detected only at ovulation stage. The synchronous increase in pituitary contents and mRNA levels suggested that ovarian maturity in masu salmon was regulated by both GTH I and GTH II.

• 한국양식학회지
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• 제17권1호
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• pp.62-68
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• 2004

A cDNA encoding the masu salmon, Oncorhynchus masou, estrogen receptor $\alpha$ (msER$\alpha$) was cloned from the pituitary gland by polymerase chain reaction (PCR). This cDNA contains an open reading frame encoding 513 amino acid residues, and the calculated molecular weight of this protein is about 56,430 Dalton. The amino acid sequences of the DNA binding and ligand binding domains of msER$\alpha$ showed high homology to those of other fish species (84-100%). Reverse transcription PCR analysis showed that the mRNA level of msER$\alpha$ in the pituitary was slightly higher in estradiol-17$\beta$(E2) injected masu salmon than that of control fish. To test the biological activity of msER$\alpha$, the cDNA was ligated to a mammalian expression vector and transfected into a gonadotrope-derived cell line, L$\beta$T2, with a reporter plasmid including estrogen responsive element. Expression of the reporter protein, luciferase, was E2 and msER$\alpha$-dependent. The masu salmon ER$\alpha$ is structurally conserved among teleost species and functions as a transcriptional activator in the pituitary cells.

• 한국양식학회지
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• 제12권3호
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• pp.185-191
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• 1999

A genetic analysis for survival in fry and juvenile stages of masu salmon was described. Data from two year-classes of masu salmon were analyzed to estimate the heritability for survival during the fresh water-rearing period. The overall survival for each year-class during 8 months of freshwater rearing were 17.8 and 11.6%, respectively. Whirling disease virus (WDV) was the main cause of death in all year-classes. Survival data obtained for offspring of 42 sires and 60 dams of masu salmon (two year classes of data) was analyzed. Average survival rates in the observation period ranged 2-87% for 1994; 0-98% for 1995, repectively. In both year-classes, heritabilities for survival derived from the sire components of variance were low(0.13-0.18), except one. Heritabilities derived from the dam components of variance ranged 0.14-0.61, including non-additive genetic and /or common enviromental effects. Correlations between survival in two long-term periods were all positive and medium to high in magnitude(0.345-0.918). Correlations between survival in non-succeeding periods were, in general, low and insignificant. Correlation between long-term survival and growth rate was found in masu salmon. The corresponding correlation in masu salmon was not significantly different from zero. Correlations between sire survival and body weight, length and condition factor of slaughter were not significant, but varied.

• 한국해양학회지:바다
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• 제12권2호
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• pp.102-111
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• 2007

RAPD analyses using 60 OPERON primers and 13 URPs were performed in order to assess the genetic variation and frequency of polymorphisms in Korean salmonids. RAPDS were very reproducible and most useful at the sub-species level. In RAPD analysis, 138 polymorphic bands were detected between Oncorhynchus masou subspecies and 99 bands were generated in two types of rainbow trout. Estimated genetic distances between O. masou subspecies were 0.28794, and between wild rainbow trout and an albino mutant was 0.22786. Each species of salmonid was well characterized using URP 4R, the obtained bands could be useful as a species specific RAPD markers.

• 한국수산과학회지
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• 제36권4호
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• pp.346-351
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• 2003

Single-cell gel electrophoresis (comet assay) was used to detect DNA single strand break in blood cells from several marine fish species. Three fish species were collected from Georgia coastal area. Mummichog, Fundulus heteroclitus showed higher DNA damage than sea bass, Lateolabrax japonicus and trout, Oncorhynchus masou masou under the same experimental conditions. Mummichogs had more alkaline-labile sites on their DNA than other fish species. The comet assay with mummichog blood cells at pH 12.5 showed a dose-response curve with the increasing concentrations of hydrogen peroxide. While the isolated leucocytes showed no increase of DNA damage after in vitro exposure to 2-methyl-1,4-naphthoquinone (MNQ), erythrocytes showed dose-dependent DNA damage. These results indicate that the comet assay can be applied successfully as a bioassay using erythrocyte for environmental monitoring.

• 한국수산과학회지
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• 제34권4호
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• pp.419-421
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• 2001

Heritability estimations of masu salmon smelt at underyearing of age were described. Masu salmon was taken from aquaculture station of Mori in Japan. After fertilization, the offsprings in each family were reared in separate egg trays and fingerling tanks. The percentage of fish in each tank which smoltified at 11-month old was recorded, and environmental and genetic factors influencing the percentage smoltification were also studied. Percentage of smoltification was not significantly affected by the number of fish held in a tank, or fish density (correlation coefficient 0.10). However, there was a high correlation ($0.821\~0.565$) between smelt percentage and growth related traits of fish in a family. Heritability estimated from total data was $0.47\pm0.13$, when effects of tanks were ignored.