• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.366-372
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• 2009

This study looked at toxicity of Mediterranean mussels, Mytilus galloprovincialis, which had accumulated paralytic shellfish toxins (PST) from early March to late May 2005 at Jinhae Bay, Korea. Alexandrium sp. was observed in low densities (< 1,000 cells/L) at the beginning of the study in March, increased rapidly in April, declined rapidly and disappeared in May. Although low densities of Alexandrium sp. were observed in March, mussel toxicity exceeded regulation level ($80{\mu}g$ STXeq. /100 g). Peak PSP (Paralytic Shellfish Poisoning) toxicity in the mussels occurred during high Alexandrium sp. cell densities in April. Mussels toxicity decreased with decline of Alexandrium sp. cell density. Major toxin components identified were $GTX_1$, $GTX_4$, followed by $C_1$, $C_2$, $GTX_2$, $GTX_3$ and neoSTX. Trace or sporadic toxin components were STX, $GTX_5$, $dcGTX_2$, $dcGTX_3$ and dcSTX. Toxin component analysis from the middle to end of the study showed that $11{\beta}$-epimers ($GTX_{3,4}$, $C_2$) were converted into $11{\alpha}$-epimers ($GTX_{1,2}$, $C_1$) and started to determine STX.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.564-572
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• 2016

In this study, we isolated and characterized Escherichia coli from mussels and inland pollution sources in or in proximity to the Changseon area on the southern coast of Korea in 2014. A total of 147 strains of E. coli were isolated from 54 mussels and 32 pollution-source samples. The susceptibility of the isolates to 24 antimicrobial agents was analyzed. The resistance of E. coli isolates to rifampin was highest at 100%, followed by cephalothin (98.6%), tetracycline (91.8%), amikacin (81.0%), ampicillin (79.6%), cefazolin (79.6%), streptomycin (73.5%), piperacillin (70.7%), gentamicin (37.4%), cefoxitin (35.4%), cefamandole (34.7%), tobramycin (29.9%), amoxicillin/clavulanic acid (24.5%), nalidixic acid (21.8%), trimethoprim (19.0%), chloramphenicol (17.7%), cefotaxime (12.9%), trimethoprim (10.9%), ceftazidime (10.2%), aztreonam (7.5%), imipenem (2.7%), cefepime (2.0%), and cefotetan (0.0%). In addition, the antimicrobial resistance of E. coli isolates from inland pollution sources was slightly greater than or similar to that of isolates from mussels.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.328-335
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• 2023

In this paper, among the various facilities used in marine farming, young bivalves of the Mytilus galloprovincialis of marine farming was placed on the deck of the fishing vessel to evaluate the environment conditions and drive shaft movement by rolling affecting the separator for the young bivalves and a clean process. There were a few studies on stress analysis of development facilities because it was difficult to access the fishing site due to the use of imported equipment and the lack of development of domestic equipment. In this study, stress analysis of the fixed part of separator for young bivalves and its adjacent part was performed on various phases when the vessel was tilted by rolling using the finite element method. In addition, the structural safety of the internal blade under the driving conditions according to the movement of the drive shaft by the hydraulic motor was confirmed through structural analysis. As a result, the connection part between the deck and the separator by rolling was confirmed to have higher stress than that of other parts due to stress concentration. In addition, it was confirmed that the maximum stress occurred on the connection part between blades. Even though the safety of the separator for marine farming was confirmed by structural analysis, it is necessary to comprehensively consider the age of vessels, the material of the deck, and the corrosion of the deck.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.203-212
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• 2015

This study was performed to describe the influence of temperature on the clearance rate and ingestion rate of the blue mussel, Mytilus galloprovincialis with three food organisms and habitat location (shell size) of mussel. Food organisms used in this experiments were Isochrysis galbana, Chaetoceros didymus and Prorocentrum dentatum. The size of mussels inhabiting higher midlittoral zone was smaller than those of lower midlittoral zone. Regardless of the kind of food organisms, filtration rates and ingestion rates of higher midlittoral mussels were higher than those of lower midlittoral mussels in experiment temperature conditions. The variation of filtration rate and ingestion rate showed same tendency with temperature. Filtration rates and ingestion rates increased with temperature, and recorded maximum values at $20-25^{\circ}C$ of temperature, and thereafter decreased gradually. Theoretical optimum temperatures showing maximum filtration rates and ingestion rates estimated from polynomial regression curves were also in the range of $20-25^{\circ}C$. Blue mussels showed different variation of filtration rate and ingestion rate with the kind of food organisms. Filtration rates and ingestion rate based on cell number were similar regardless of habitat location(tidal elevation) and food organisms. Ingestion rates based on carbon content showed very high values in case of P. dentatum beside I. galbana and C. didymus as food organism.

• Ocean and Polar Research
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• v.36 no.2
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• pp.121-134
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• 2014

Sessile marine bivalves including mussels, oysters and clams are often used as a sentinel species in coastal environmental monitoring since changes in the environmental quality are often well preserved in their tissues and shells. In this study, we investigated overall health condition of the Mediterranean Mussel, Mytilus galloprovincialis on the south coast using histology. Reproductive condition as gonad index (GI), condition index (CI) as a ratio of the tissue weight to the shell weight, digestive gland atrophy (DGA), types of parasites, and pathologic conditions including erosion, necrosis, hemocyte infiltration, and neoplasia were examined from each histological preparation. GI decreased from March to July then increased from July to September and spawning mussel could be observed as early as in April and the activity continued until September. CI also followed the monthly changes in GI, indicating that decrease in CI was associated with the weight loss due to spawning. DGA increased from March to June, decreased in July and increased from July to September. High DGA values observed in June and September were coincided with spawning and high water temperature. Histology also showed high prevalence of erosion in the digestive gland in June (36.0%) and September (56.4%), suggesting that high water temperature and spawning acted as environmental stressors. No parasitic organism was identified during the survey, although some symbiotic copepods were observed. Histology was found to be useful and affordable technique in monitoring the overall health of mussel, providing useful pathologic information of the cells and tissues.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.9-14
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• 2011

This study was examined digestive enzyme activity in the crystalline style of the three species of bivalves. Bivalves used in this study were Tegillarca granosa (n=61), Mytilus galloprovincialis (n=30) and Saxidomus purpuratus (n=30) and collected from southern coast of Korea on May 2010. Digestive enzymes activities in the crystalline style were assayed in spectrophotometer. Amylase and cellulase occupied approximately 90% of digestive enzyme in crystalline style of T. granosa, M. galloprovincialis, and S. purpuratus. And protease activity in crystalline style of T. granosa, M. galloprovincialis and S. purpuratus showed the lowest values to 0.02, 0 and 0.08%, respectively. Digestive enzyme activity in crystalline style of three species was measured in the order of cellulase > amylase > chitinase > laminarinase.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.581-585
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• 1985

This study was carried out with blue mussels at Otsuchi Bay in Japan from August 1981 to May 1982, in order to investigate the effect of the parasitic pea crab (Pinnotheres pholadis) on the reproductive capacity of host blue mussels (Mytilus edulis galloprovincialis). The results show that pea crabs delay gonad development of host mussels about one month and lower their fatness rate by intercepting nutrients. The parasitization with pea crabs is thought not to prevent spawning activity itself, but to reduce the number of germ cell resulting in the reduced space of gonads.

• 한국해양학회지
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• v.26 no.2
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• pp.101-107
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• 1991

We report on the seasonal fluctuation of a Poecilostomatoida copepod, Pseudomyicola spinosus associated with the blue mussel, Mytilus galloprovincialis in the Yongsan River estuary (34$^{\circ}$47N, 126$^{\circ}$27'E). P. spinosus has four generations a year, seasonally succeeding each other. The generation that occurs during summer has the highest number of individuals. From June to October with the exception f September, males dominated while female outnumbered from November to May with the exception of January. It is possible to find ovigerous females all year with the exception of February. The largest number of ovigerous females occurs a month earlier than copepodids do. The percentage of C1 to C3 is approximately 4% of the total number of copepodids, indicating that in situ infestation by copepodids mainly occurs in C4 stage.

• 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.