• Journal of fish pathology
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• v.26 no.3
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• pp.193-206
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• 2013

The ark shell, Scapharca broughtonii is a marine bivalve mollusks belonging to the family Arcidae and important seafood for Korean and Japanese, and southern coast is brisk bays for the ark shell aquaculture. However, productivity of ark shell from these regions were rapidly reduced during the last decade due to mass mortality. The reason of this great damage has not yet been identified. To overcome this economic loss, diverse investigations were focused on environmental factors that affects in the physiology of S. broughtonii, but microbiological researches were performed insufficiently. Hemoglobin is one of the major blood component of ark shell and is damaged by some species of bacterial toxins. We concentrated on this red pigment because hemolysis could be the cause of ark shell mortality. In this study, we analyzed microbial diversity of underwater sediments in coastal regions and also existences in the body of S. broughtonii. We investigate about 4,200 isolates collected from June to September for microbial diversity of sediments and ark shell. We screened all of culturable microorganisms, and identified 25 genera 118 species, 24 genera 89 species, 30 genera 109 species and 39 genera 141 species, and selected 140 unique colonies for identification and challenge assay.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.603-604
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• 2001

이매패강 개량조개과에 속하는 개량조개 (Mactra chinensis Pjilippi)는 우리나라, 중국, 일본 등지에 분포하며 서해안과 남해안의 조하대 사니질에 서식한다. 지금부터 15년전에는 서해안에 간척공사가 대단위로 일어나지 않았기 때문에 개량조개가 갯벌에 다량 서식하고 있어 쉽게 발견할 수 있었으나 지금은 환경변화로 극히 일부지역에서만 출현하고 있는 실정이다. (중략)

• The Korean Journal of Malacology
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• v.25 no.2
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• pp.105-112
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• 2009

We investigated the degree of obesity, histological development stages of gonads and sexual maturation induction rates of comb pen shell, Atrina pectinata, per the type of micro-algae supplied. Terms of maturation by singular or mixed supply of microalgae, it was found that maturation of the female was the quickest at 60.0% by the Tetraselmis tetrathele (Tet). experiment group followed by 57.1% by the Chlorella ellipsoidea (Chl). experiment group and 16.7% by the Phaeodactylum tricornutum (Pha). experiment group. However, there were no significant differences between Tet. experiment group and Chl. experiment group. As for the male, maturation was the quickest at 60.0% by the Tet. experiment group followed by 16.7% by the Chl. experiment group and 14.3% by the Pha. experiment group. In light of these results, Tet. is concluded to be a very useful feed organism in breeding the mother comb pen shells. Upon completion of the experiment, the sexual maturation induction rate for the female was found to be the highest at 82.0% in the Tet. experiment group followed by 72.0% by the Chl. experiment group, 64.0% by the Pha. experiment group and 58.0% by the mixed micro-algae experiment group. During the period of experiment, the survival rate was the highest at 94.4% by the mixed micro-algae experiment group followed by 90.0% by the Pha. experiment group, 83.1% by the Tet. experiment group and 78.8% by the Chl. experiment group.

• Korean Journal of Microbiology
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• v.35 no.3
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• pp.185-191
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• 1999

This study was conducted to investigate the vibrio flora in an edible shellfish. sunset shelfish. Soletelliim olivacen. which were collected in the estuarine area. Dadaepo near Nakdong River in Korea lkoin January 1997 to November 1997. Including five pathogemc vibrios (Vibrio alginolyticus, Vibrio pamhaemol~~licz~s, Vibrio cholerae non-01. Vibrio vulnificus, and Vihrio jl~~vinlis), a lotal of eight species of vlbr~os (Vi61-io splendidrrs biovar I, Vibrio splendidus biovar 11, Vibrio snlrnonicida and Vibrio tr,~biasllii) were identified from the sunset shellfish by heir biochemical characters. The isolation of Vihrio pamhaemolyricns, which is known not to grow below $15^{\circ}C$, in winter season indicates that the sunset shelllish is one oT the natural owl.- wintering hosts for Vibrio parahuemolyticus.

• Journal of fish pathology
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• v.1 no.1
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• pp.31-37
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• 1988

An experiment was carried out in order to reveal the infection species of trematode and the infection demage in the marine bivalves. Metacercaria of Echinostomatidae were found in Mactra veneriformis, Cyclina sinensis and Solen strictus in the vicinity sea of Naecho-do, the estuary of the Keum River in the western coast of Korea. The metacercaria detected from Solen strictus were fed by Larus crassiostris, at 16 days after infection, the adult worm could be seceded. The metacercaria of Himasthla kusasigi were detected from Mactra veneriformis and Cyclina sinensis, their infection rates were 70.4% and 85.7% respectively. The partial infection rates with respect to the body parts were 40.4% and 77.3% in the foot, 17.0% and 12.4% in the gill, 12.6% and 10.3% in the mantle in order. The metacercaria of Acanthoparyphium were found from Solen strictus. The total infection rate was 63% and the partial infection rate was 63% and the partial infection rate was shown foot, mantle and gill in order. The adult worm ceded from Larus crassiostris was indentified as Acanthoparyphium tyosenensis Yamaguti, 1938 from view point of its physical characteristics. Therefore, Mactra veneriformis, Cyclina sinensis would be added as new intermediate hosts, and Echoinostoma decteded from Mactra sulcataria which was studied by author(1969) was revealed as larvae of Acanthoparyphium tyosenensis.

• Journal of Aquaculture
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• v.20 no.1
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• pp.31-40
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• 2007

To find out the effect of the spat planting time and environmental factors in the arkshell, Scapharca broughtonii (Schrenck), we investigated the growth, survival rate of arkshell and habitat characteristics in Gamak Bay, Yeoja Bay and Saryang Island. We planted artificial spats of arkshell in Gamak Bay and Yeoja Bay at November 2004, and also planted domestic and Chinese natural spats in Saryang Island at March 2005. We measured growth, survival rate of arkshell, physiochemical parameters of the water mass (water temperature, salinity, dissolved oxygen, nutrients and chlorophyll a) and characteristics of the sediment (oxygen penetration depth, oxygen microprofiles, ignition loss and chemical oxygen demand) by monthly. The cumulative survival ratio of arkshell in Gamak Bay was the highest at December, whereas the ratio of arkshell in Yeoja Bay was recorded as 0% at October. The monthly growth rates of arkshell length in Gamak Bay and Yeoja Bay were the highest in May and the growth rate of the Korean arkshell in Saryang Island was higher than Chinese ones significantly. The high mortality (> 65%) of the arkshell in Yeoja Bay during summer probably caused by high water temperature, inflow of low salinity water, and low dissolved oxygen concentration in sediment. The concentrations of nutrient and sediment COD were considered to play an important role in the monthly survival ratio of arkshell in Gamak Bay and Sarayng Island. We suggest that the growth and mortality of arkshell might be influenced to the planting time of spat and the habitat characteristics.

• Proceedings of the Malacological Society of Korea Conference
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• 2001.11b
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• pp.149-150
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• 2001

• Proceedings of the Malacological Society of Korea Conference
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• 2001.11a
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• pp.29-30
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• 2001

• Journal of fish pathology
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• v.16 no.3
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• pp.203-213
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• 2003

The present study was conducted to research some parastic trematodes species in marine bivalves which are widely distributed in the western sea in Korea. From April, 2001 to October, 2002, marsh calm (Corbicula japonica) were obtained from Kochang bay near the Sunun temple and razor calm (Sinonovaculla constricta) from Kaehwado. Short necked calm (Ruditapes philippnarum) were sampled from Ochungdo, Mardo and Kaeyado. Cercaria corbiculae was found in the gonad of C. japonica with a low infection rate of 0.83%. The cercaria and the sporocyst were sized $278{\times}98{\mu}$ and $890{\times}275{\mu}$, respectively. Some encysted larvae of Parvatrema duboisi sized $0.351{\times}0.182mm$ were firstly found in the mantle of S. constricta in Korea. Each S. constricta contained 1-9 cysts and the infection rate was 48.3%. Cercaria tapidis was found in the both gonad and mantle of R. philippinarum. The annual average infection rate in the R. philippinarum from Ochungdo was 7.7%. This rate was much higher than those from Solri near the Kum river estuary in 1981. The infection rate of C. tapidis in R. philippinarum was different in sizes. The maximum rate was 4.8% in size 3.6-4.0cm and the minimum rate 0.8% in size 4-5cm.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.310-311
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• 2003

본 연구에서는 폐수산자원인 불가사리와 조개껍질 분말을 이용한 탈수보조제(물리개량제)의 가능성을 확인하였다. 불가사리와 조개껍질을 이용한 탈수보조제는 유가자원 소모라는 기존의 탈수보조제의 문제점을 보완하여 폐자원의 자원화라는 이점이 있으며 탈수케이크의 함수율을 효과적으로 낮추어 주어 소각등의 후속공정에 도움을 줄 수 있는 것으로 사료된다. 뿐만아니라 천연 비료로 사용되어지는 불가사리의 활용이라는 점에서 탈수슬러지 퇴비화등 자원 재이용에의 적용성 또한 증대시킬 수 있다.