• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.287-294
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• 2010

Objectives : The aim of this study was to verify the intersexuality of Crassostrea gigas and Ruditapes philippinarum in southern coastal waters of Korea. Methods : Specimens of Crassostrea gigas (n=363) were collected from six areas of Tongyeong, Geoje and Yeosu. Ruditapes philippinarum (n=221) was collected from five areas of Yeosu. The sex ratio and intersexuality were determined after observing gonad preparations. Results : The rate of intersexuality in Crassostrea gigas was 16.25%, with females (24.79%; n=30/121) exhibiting a higher rate than males (11.98%; n=29/242). The rate of intersexuality in Ruditapes philippinarum was 24.43%, with females (37.76%; n=37/98) exhibiting a higher rate than males (13.82%; n=17/123). Conclusions : The results of this study suggest that intersexuality is induced by aquatic pollutants such as endocrine disrupting chemicals (EDCs).

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.377-380
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• 2013

This study investigated concentration of metal ions in sediment and intersexuality in Polymesoda erosa and Lutraria lutraria. Samples were collected from five areas of Ha Long Bay in October, 2012. The concentration of metal ions showed that Al ($37390.0{\pm}11816.5mg/kg$) was highest and Mn ($360.4{\pm}101.4mg/kg$) was second high concentration. Cd ($0.04{\pm}0.05mg/kg$) was lowest. The intersexuality was 14.3% in P. erosa and 9.1% in L. lutraria that observed only in female.

• Development and Reproduction
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• v.17 no.2
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• pp.73-78
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• 2013

This study histologically describes the intersexuality of Scomberomorus niphonius collected from the coastal area near Jeju Island. A total of 126 S. niphonius, collected from March to July 2012 with a total length of 62.4 cm (${\pm}17.5$) and a total weight of 1,701.9 g (${\pm}1,528.9$) were used for analyses. From a histological perspective, two types of intersex were confirmed. One type had scattered germ cells from the opposite sex within the gonad. The second type developed germ cells from the opposite sex in the connective tissue of the outer gonadal membrane. The intersexuality was 14.3% (n=18/126), with females (21.3%; n=16/75) exhibiting a higher rate than males (3.9%; n=2/51). There was no displayed correlation between intersexuality and the total length and weight.

• Development and Reproduction
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• v.25 no.3
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• pp.123-131
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• 2021

We report on the gonadal structure abnormality and intersexuality found from a survey regarding the reproductive potential of the rock bream, Oplegnathus fasciatus, along the southern coast of Korea. In total, 448 samples were collected for histological analysis (total length 27.5±6.8 cm; total weight 522.9±385.6 g). The sex ratio (F:M) was 1:0.46 (n=307:141), with 68.5% being females. The frequency of oocyte atresia and ovarian neoplasm in the females was 85.3% and 21.5%, respectively, and the frequency of testicular lobule and cyst deformation and testicular neoplasm in the males was 73.1% and 37.6%, respectively. The scale formation in the ovary and testis was approximately 2.0% for both sexes. The intersexuality was 42.2%, with the intersexuality among females being 49.5%, which was significantly higher than that of males (26.2%). Such findings indicate a negative impact on the reproductive output of the rock bream along the southern coast of Korea; however, a more detailed study is required to ascertain accurate causes.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.197-202
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• 2016

This research reports the intersexuality of bivalves, such as Crassostrea gigas, Mytilus galloprovincialis, Rupiditapes philippinarum, Gomphina veneriformis and Barnea davidi discovered during the process of investigating the ecological health status of coastal waters of Korea. In intersex ovaries, the opposite germ cells were observed either individually or in groups in the interfollicular space and inside the oogenic follicle. Oocytes in the intersex testis were at the previtellogenic or initial vitellogenic stage. They were either scattered individually or in groups in the interfollicular space and inside the spermatogenic follicle. The intersexuality in C. gigas was 10.4% (n = 19/183), while female (12.2%, n = 6/49) exhibited a higher proportion than male (9.7%, n = 13/134). The intersexuality in M. galloprovincialis was 31.7% (n = 19/60), while female (36.4%, n = 12/33) exhibited a higher proportion than male (25.9%, n = 7/27). The intersexuality in R. philippinarum was 11.2% (n = 11/98), while male (16.7%, n = 7/42) exhibited a higher proportion than female (7.1%, n = 4/56). The intersexuality in G. veneriformis was 28% (n=30/107), while male (31.5%, n=17/54) exhibited a higher proportion than female (24.5%, n=13/53). The intersexuality in B. davidi was 18.4% (n = 7/38), while female (35.7%, n =5 /14) exhibited a higher proportion than male (8.3%, n = 2/24).

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.137-142
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• 2015

This study investigated concentration of trace metals, intersexuality and histopathology of digestive gland in Ruditapes philippinarum. Samples were collected from three areas of Gamak Bay in May, 2010. The concentration of trace metals showed that Al was highest, Zn was second high concentration and the lowest concentration was Cd. The intersexuality was 18.5% and female was higher than the male. Intersex type was observed one type. Destruction of digestive tubule epithelium was highest among other biomarkers in digestive gland. Distribution of basophilic cell was 5.8% and lipofuscin was 1.8%.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.88-96
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• 2021

The purpose of this study was to report the intersex identified in the oyster Crassostrea gigas (n=410, SH 43.3±11.4 mm) in the waters around 13 uninhabited islands near Yeosu. The overall sex ratio (male: female) was 1:1.1, but there was a difference between the sampling areas. In Gajangdo, Sogyeongdo, and Jungsamdo, females showed a high ratio of 65% or more, and in Songdo, Chodo, and Buseodo, males showed a high ratio of 65% or more. The overall intersexuality was about 12.8%, which was high in males, about 34.7% in females and 64.3% in males. Intersexuality was the highest with about 43.8% in Chodo of Gamak Bay. Histologically, intersex could be divided into three types: intrafollicular type, interfollicular type and mixed type. Among these three types, the intrafollicular type was the most dominant with about 81.6%. The intersex cause of oysters reported in this study is considered to require detailed research in the future.

• Journal of the korean veterinary medical association
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• v.15 no.1
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• pp.11-14
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• 1979

• Journal of fish pathology
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• v.23 no.2
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• pp.211-219
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• 2010

Specimens were collected from the coastal region near industrial complex of Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang in 2008 and 2009. The total number of individuals used in analysis was 1,289 of Acanthogobius flavimanus, Chelon haematocheilus, Hemibarbus labeo, Leiognathus nuchalis, Mugil cephalus and Synechogobius hasta. The sex ratio in the total individual was 1:0.73 (female:male). Specific sex ratio of fishes in the areas, namely the Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang were 1:0.79, 1:0.81, and 1:0.25, respectively. Especially, female in Yeosu-Gwangyang was higher than male. The intersexuality in the total individual was 11.7%. Intersexuality of fishes in the areas were 4.98, 14.39 and 25.0% in the Ulsan-Onsan, Sihwa-Ansan and Yeosu-Gwangyang, respectively. It was indicated female higher than male in Ulsan-Onsan and male higher than female in Sihwa-Ansan and Yeosu-Gwangyang.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.33-41
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• 2013

This study investigated concentration of metal ions, intersexuality and histological alterations of digestive gland in Mytilus galloprovincialis. Samples were collected from two areas of Gamak Bay in May, 2010. The concentration of metal ions showed that Al ($366.5{\pm}249.7$ mg/kg) was highest and Zn ($179.5{\pm}67.8$ mg/kg) was second high concentration. Co ($1.0{\pm}0.2$ mg/kg) was lowest. The intersexuality was 26.4% and males (38.8%) was higher than the females (12.9%). Intersex type was observed four types. Destruction of digestive tubule epithelium was highest among other biomarker in digestive gland. Distribution of basophilic cell and lipofuscin was 6.1% and 1.5%, respectively.