• Journal of Life Science
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• v.9 no.3
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• pp.262-267
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• 1999

Mitochondrial DNA (mtDNA) polymorphism of the blue mussel (Mytilus edulis) species complex sampled from the east coast of Korean was studied using a partial sequence of COIII gene (336 bp). Samples obtained from three localities on the east coast of Korea revealed four haplotypes with two clearly differentiated mitochondrial clades (termed clades B and E), separated by 4.2% of minimum sequence divergence. This pattern indicates no difference between east and south coasts of Korea. According to population genetic theory on evolutionary characteristics of mtDNA, we concluded that mtDNA introgression from M. edulis to M. gallprovincialis might be a source for mtDNA polymorphism found in mussels on the east coast of Korea.

• Korean Journal of Remote Sensing
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• v.38 no.5_3
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• pp.979-989
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• 2022

We examined changes in the shell valve movements (SVMs) of Mytilus edulis and Crassostrea gigas using a Hall element sensor to investigate the early detection of the toxic dinoflagellate Alexandrium pacificum. No increase or decrease was observed in SVMs caused by the non-toxic algae Isochrysis galbana in both M. edulis and C. gigas. However, when M. edulis and C. gigas were exposed to A. pacificum, which causes paralytic shellfish poisoning, the average SVMs for 12 hours before and after exposure increased from 1.25 times/hr to 2.13 times/hr and 2.23 times/hr to 8.91 times/hr, respectively. After exposure to A. pacificum, the SVMs of M. edulis increased rapidly within 1 hour and then decreased gradually. However, C. gigas showed high SVMs until 4 hours after exposure. SVMs of C. gigas appeared to be more sensitive to toxic dinoflagellate than those of M. edulis. Therefore, these results are expected to be used as basic data for the establishment of a biological monitoring system for early detection of the toxic dinoflagellate A. pacificum.

• Journal of Aquaculture
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• v.22 no.1
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• pp.68-73
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• 2009

Yeast has been widely used as a food organism for mass culture of rotifer and also considered as a partial substitute food for microalga in shellfish culture. But the dietary value of yeast is poorer than that of microalga due to its low nutrition and thick cell wall. This study was carried out to find a nutritious yeast species as a food organism and to investigate the nutritional value of manipulated yeast for shellfish. First of all, three species of yeast (Saccharomyces cerevisiae, Candida utilis, Kluyveromyces fragilis) and their manipulated yeast were tested on the survival (%) and growth of Artemia nauplii and Mytilus edulis larvae, which were representative filter feeding animal and easy to control. The survival (%) and growth of Artemia nauplii fed C. utilis were higher than those fed S. cerevisiae or K. fragilis. The growth of Artemia nauplii and M. edulis larvae, which were fed manipulated yeast was higher than that fed non-manipulated one. The manipulated yeast with higher removal rate of cell wall showed better dietary value for Artemia nauplii and M. edulis larvae. M. edulis larvae fed mixed-diet with Isochrysis galbana (50%) and manipulated C. utilis (50%) showed significantly higher growth than those fed single-diet with I. galbana. It means that manipulated C. utilis can substitute I. galbana at least 50% for M. edulis larvae.

• Animal cells and systems
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• v.3 no.1
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• pp.79-87
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• 1999

Mitochondrial DNA (mtDNA) from 54 specimens of the blue mussel (Mytilus edulis) species complex sampled from the southern coast of Korea was assayed for polymorphism with a portion of the COIII gene (336 bp). Fifteen haplotypes were found. PAUP, one-step networks, and PHYLIP analyses revealed the presence of two clearly differentiated mitochondrial clades (termed clades B and E), separated by 3.6% of minimum sequence divergence. The distribution pattern of the species appears to be consistent with category II of the phylogeographic pattern sensu (Avise et al., 1987): the presence of two discontinuous and distinct mtDNA genotypes in the same geographic region. This unusual mitochondrial polymorphism was explained by the presence of the Mediterranean species, M. galloprovincialis, possessing mtDNA of both M. galloprovincialis and M. edulis.

• Journal of Aquaculture
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• v.18 no.3
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• pp.142-146
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• 2005

In this study, the reattachment processes of small and medium size of spot of Mytilus coruscus and M. edulis were observed. The small spats (Shell length, SH, $3{\sim}7mm$) of hard shelled mussel, M. coruscus showed 100% reattachment rate within 7 minutes after the detachment of byssus thread and 100% survival rate. While large spats (SH 25 mm) showed 85% reattachment rate within 5 hours and 100% survival rate for 24 hours. The reattachment rate of M. edulis (SH 30 mm) was higher than that of M. coruscus (SH, 28 mm). The thread consisted of three identifiable structures; adhesive disc, adhesive thread and adhesive root. The adhesive disk and adhesive thread of M. coruscus were larger and thicker than those of M. edulis, whereas the thickness of adhesive root was the other way round. Further studies are required to identify the relationship between the structure of byssus thread and attachment ability. This study suggests that the sizes of spats could be an important factor in determining the timing of removing and reattaching mussel seedling for aquaculture or releasing to the sea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.165-170
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• 1992

The internal shell morphology of the blue mussel, which were collected from Korea and Japan were studied. The range of the mean ratio between anterior adductor muscle scars to shell height in each locality were between 62.47 in Yongdok to 54.17 in Uichang. These values were very similar to that of M galloprouincialis in Mediterranean than that of M edulis in Europe. And the range of the mean ratio between hinge plate length to shell height were between 61.31 in Jukbyon to 56.15 in Otuschi. Also these values were similar to that of M. galloprovincialis in Mediterranean. Based on the mean ratio between anterior adductor muscle scars and hinge plate length to shell height, it was suggested that the Korean and Japanese blue mussel is certainly identical to the Mediterranean species, Mytilus galloprovincialis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.1
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• pp.71-76
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• 2002

To understand the effect of heated effluent from a nuclear power plant on marine organism, experimental culture of Halocynthia roretzi was carried out at heated effluent of Wolsung nuclear power plant from January to December 1996. Temperature was $11.2\~27.9^{\circ}C$ and salinity was $32.54\~34.59\%_{\circ}$ during the culture period, The Growth of H. roretzi on lower area of Bonggil-ri (St. 1) was not normal in height, breadth and weight due to heated effluent. Daily growth rate (DGR) of H. roretzi about Kampo area (St, 4) was significant other station, and St. 1 was significant from other station except St. 4, Mytilus edulis was major fouling organism (over $90\%$) that were M. edulis, Dideninum moseleyi, Styela clava in experiment culture farm. St. 1 was higher (mean 143 individual) and St. 4 was lower (mean 56 individual) appearance attached of M. edulis. Growth of H. roretzi reduced when attached number of M. eduiis was increased, because correlation between DGR and number of M. edulis was negative.

• Journal of Aquaculture
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• v.13 no.2
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• pp.119-128
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• 2000

Exposure to air and increased temperature induced successful spawning in Mytilus edulis, M. coruscus Crassostrea gigas and Pinctata fucata martensii. Developmental durations required for an egg to attain D-shaped larva and the D-shaped larva to reach pediveliger stage were estimated in these bivalves. Size of fertilized eggs was the largest (70.3 ${\mu}m$) in M. coruscus and the smallest (45.3 ${\mu}m$) in P. fucata martensii. At 17$^{\circ}C$, M. edulis and M. coruscus attained D-shaped larval stage within 48 hours after fertilization but those of C. gigas and B. fucata martensiii within 24 and 22 hours at 21 and 26$^{\circ}C$, respectively. The development duration required for a D-shaped larva to attain pediveliger stage was the longest (27 days) in M. coruscus and ranged between 20 and 22 days for the others. The shell length of the pediveliger was the longest (274.9 ${\mu}m$) in C. gigas and smallest (190.9 ${\mu}m$) in P. fucata martensii Length and height of larval shell was highly correlated with each other in all the 4 species. The shell height of C. gigas was more than the shell length beyond the size of 100 ${\mu}m$ shell length. However, shell length of the others was always longer than shell height at the larval stage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.1
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• pp.49-54
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• 2006

Cultured cells of the toxic Alexandrium tamarense were fed to four mussel species, Mytilus coruscus, M. edulis, M. galloprovincialis and Septifer vulgatus, to examine the interspecies and interlocality differences in the ability to accumulate paralytic shellfish poisoning (PSP) toxins. Toxin content of A. tamarense cells varied during culture period. In contrast, toxin composition in the cell (C1,2, GTX1-4 and neoSTX) was constantly stable. In feeding experiment, the four mussel species collected from Geoje intoxicated after uptake of A. tamarense. Toxin content ($average{\pm}SD\;{\mu}g$ STXeq/100 g) of M. coruscus, M. edulis, M. galloprovincialis and Septifer vulgatus were $1,660{\pm}79,\;3,914{\pm}2,242,\;5,626{\pm}1,620\;and\;958{\pm}163$, respectively. Toxin profiles included C1,2, GTX1,4 and neoSTX as the major components, and dcGTX2,3, GTX2,3, neoSTX and STX as the minor ones. Toxin accumulation of three mussel species collected from Pohang, Geoje and Anmyon-do showed interspecies and interlocality differences. Toxin content ($average{\pm}SD\;{\mu}g$ STXeq/100 g) were $91{\pm}4,\;151{\pm}14,\;39{\pm}3$ in M coruscus, $189{\pm}1,\;231{\pm}11,\;206{\pm}15$ in M edu/is and $214{\pm}28,\;326{\pm}30,\;291{\pm}26$ in M. galloprovincialis in order of Anmyon-do, Geoje and Pohang.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.18 no.2
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• pp.80-88
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• 2013

The present study was conducted to evaluate relationship between nonylphenol uptake rate and clearance rate of Ruditapes philippinarum, Corbicula japonica and Mytilus edulis. Variation of the temperature and body size of the bivalves was used to modulate clearance rate and nonylphenol uptake rate in this experiment. Clearance rate and nonylphenol uptake rate experiments were determined for two different size classes of the bivalves (R. philippinarum: 0.35, 0.73 g, C. japonica : 0.047, 0.1000g, M. edulis: 0.30, 0.37 g; mean flesh dry weight) and three different temperature regime (5, 13 and $18^{\circ}C$). Weight-specific clearance rate in all animal size and temperature ranges increased in the order of R. philippinarum, C. japonica and M. edulis. The weight-specific nonylphenol uptake rate did not show specific trend among species. The clearance rate and nonylphenol uptake rate generally decreased with animal size and increased with water temperature. For all three species nonylphenol uptake rate had a strong relationship with clearance rate. For a given clearance rate ranges, the nonylphenol uptake rate was in the order of R. philippinarum > C. japonica > M. edulis. The results suggest that water ventilation capacity of filter-feeding organisms is an important physiological factor controlling uptake rate of dissolved nonylphenol.