• Parasites, Hosts and Diseases
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• v.32 no.3
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• pp.157-162
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• 1994

A highly endemic focus of human infection with Heterophves nocens (Heterophyidae) was discovered from a small coastal village of Shinan-gun, Chollanam-do, for the first time in Korea. Fecal examinations by cellophane thick smear and formalin- ether sedimentation techniques revealed 42.9% heterophyid egg Positive rate out of 98 inhabitants examined. It was difficult to confirm the species of heterophylds only by eggs. In order to collect the adult flukes, the egg Positive cases were treated with 10 mg/kg single dose of praziquantel and purged with magnesium sulfate, and the adult worms were collected from the diarrheic stools. From each of 18 cooperative patients 1 to 1,124 (total 4,730) H. nocens worms were recovered, together with a few to large numbers of heterophyids (Pvginiopsis summa, Stictonora juscatunl and for gymnophallids (Gvmopholloides stool) . It is speculated that H. nocen might be widely distributed along the southwestern coastal areas where the brackish water fish such as the mullets or gobies are popularly eaten raw.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.160-165
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• 2020

Seasonal fluctuation in abundance and species composition of fish in coastal waters off Samcheonpo were investigated using seasonal samples collected by a beam trawl in 2019 to compare the variation of species composition and dominant species with previous studies. A total of 6,518 fish were sampled and classified into 44 species, 30 families, and 6 orders. The dominant species were Nuchequula nuchalis (1,542 individuals, 23.7%), Platycephalus indicus (529 individuals, 8.1%), Thryssa kammalensis (437 individuals, 6.7%), Argyrosomus argentatus (403 individuals, 6.2%), and Acanthogobius flavimanus (354 individuals, 5.4%). The highest number of individuals was found in July (2,385 individuals), while the lowest number of individuals was found in January (925 individuals). The diversity index was the highest in April (H'=2.733) and the lowest in July (H'=2.546).

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.202-220
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• 1997

A total of 57 species of fish species was collected by a trawl from the eelgrass bed in Kwangyang Bay. The dominant species were Pholis nebulosa, Syngnathus schlegeli, Leiognathus nuchalis, Pseudoblennius cottoides, Sebastes inermis, Favonigobius gymnauchen, which accounted for 69.9% of the total numbers of fish collected. Fish collected in the study area were primarily small fish species or early juveniles of large fish species. Only about 10% of fishes which were collected in the eelgrass bed exceeded 15cm in standard length. Seasonal variations in both species composition and abundance were major characteristics in the study area. The peak abundance occurred in spring, while the number of species was the highest in fall. However, both the number of species and abundance of fishes showed the lowest values in winter. High species diversity indices were observed in fall. Temperature, eelgrass standing crop and abundance of food organisms influenced seasonal changes of the fish community in the study area. More abundant and more diverse fishes were collected during nighttime than daytime.

• Development and Reproduction
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• v.9 no.2
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• pp.135-142
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• 2005

Vitellogenins(VTGs) are the precursor of egg-yolk proteins in most oviparous species from invertebrates to vertebrates. In oviparose vertebrates, VTGs are synthesized in the liver and transported through the blood to oocytes. In female fish, concentrations of plasma VTG increase rapidly at onset of vitellogenesis in the normal reproductive cycle. Male fishes also possess the gene for VTG, but plasma concentrations of the protein typically remain small, presumably due to low levels of endogenous estrogens. However, exposure of males to exogenous estrogenic mimics can result elevated. Therefore, the VTG in fish can be used as a useful biomarker for appropriate tools of endocrine disrupting compounds effects. In this studies, we prepared the test methods that can measure the plasma VTG level in the gobies that live in polluted area with mimic estrogen. For the purpose, we purified VTG of floating goby(Chaenogobius annularis) and prepared specific monoclonal and polyclonal antisera to yolk protein, then developed a sandwich competitive ELISA system for measurement of plasma VTG levels. Validation for the ELISA system using monoclonal and polyclonal antibodies against VTG was tested. The absorbance curve of serial dilutions of serum from vitellogenic female was paralleled to the standard curve of VTG, but normal male was not paralleled. The developed sandwich ELISA system was measured for VTG levels in plasma of common goby(Acanthogobius flaviman) and javeline goby(A. hasta) as well as in plasma of floating goby(C. annularis).

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.166-174
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• 2013

Analysis of the fish community in the Lagoon Cheongcho, Korea, was investigated in 2008 and in 2012. A total 48 species, belonging to 26 falmilies, were sampled during the period. The dominant species was Tribolodon hakonensis (75.2%), and subdominant species were Acanthogobius flavimanus (5.4%), Pungitius kaibarae (3.1%). The results of the fish ecotypes according to origin of water body was compared by surveyed year, freshwater fish was reduced, whereas those of brackish water and seawater fishes were increased. Moreover, the result of similarity analysis based on species and individuals in five lagoons were divided into 2 major groups based on their similarity, and Lagoon Cheongcho was included group 'A' with Lagoon Gyeongpo, as having a montinous inflow of seawater. Hence, according to the characterization according to the analysis of fish community, Lagoon Cheongcho has lost the characteristics of a lagoon, and oceanization is considerably progressed. Therefore, we are considering the provision of a management strategy for hydrarch succession, as well as continuous research, in order to manage the recovery of essential characteristics of the lagoon ecosystem. Hence, according to the characterization according to the analysis of fish community, Lagoon Cheongcho has lost the characteristics of a lagoon, and oceanization is considerably progressed. Therefore, we are considering the provision of a management strategy for hydrarch succession, as well as continuous research, in order to manage the recovery of essential characteristics of the lagoon ecosystem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.5
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• pp.309-315
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• 2005

Changes of sex steroid hormones in the plasma of yellowfin goby, Acanthogobius flavimanus were investigated in relation to the gonadosomatic index (GSI), the hepatosomatic index (HSI) and gonadal development. The GSI in females rose rapidly in November and remained high from December to May $(7.26\pm0.89­6.62\pm0.02)$. The Male's GSI also increased gradually from November and was highest in May $(0.16\pm0.08)$. The HSI in both sexes was in reverse correlation with the GSI, and the HSI was low during the spawning season (February-May). In females, the $estradiol-17{\beta}\;(E_2)$ level increased during vitellogenesis (November and December) and reached its maximum $(8.13\pm2.87 ng/mL)$ at the maturing period, in January. $17{\alpha},\;20{\beta}$-dihydroxy-4-pregnen-3-one$(17{\alpha}20{\beta}OHP)$ gradually increased from October $(0.063{\pm}0.02ng/mL)$ to March $(0.16{\pm}0.02ng/mL)$ and increased rapidly in May. The level of testosterone (T) showed a similar tendency of $E_2$. In males, T increased gradually during spermatogenesis from September to December $(0.14{\pm}0.06­0.26{\pm}0.10ng/mL)$ and peaked in January $(0.36{\pm}0.29 ng/mL)$ when the spermatozoa filled the testis. 11-KT also rose markedly in January and then decreased. On the other hand, $17{\alpha}29{\beta}OHP$ in males did not show any clear tendencies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.4 no.2
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• pp.47-54
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• 1971

The difference in growth rate of p. orientalis cultured on muddy bottom region and sandy bottom region in a pond filled with sea water were studied. For the investigation of the growth rate, the body length and the body weight were determined. Five individuals from each experimental region were sampled in random. The samples were collected at ten-day intervals. The survival rate, the qredator of p. orientalis, and the water conditions during the experimental period were also determined. The results in this study are summerized as follows: 1. The growth rate of p. orientalis which was cultured in the muddy bottom region was greater than that in the sandy bottom region. This is attributable in either case regardless of whether they were cultured with or without food, 2. The relationship between the culturing period (X) and the body length (Y) is : Muddy bottom, Food Y=0.58497X+25.05210 Sandy bottom, Food Y=0.51030X+26.57900 Muddy bottom, No food Y=0.22352X+32.79360 Sandy bottom, No food Y=0.l1418X+31.20740 3. The relationship between the culturing period (X) and the body weight (Y) is : Muddy bottom, Food Y=0.09062X-2.11140 Sandy bottom, Food Y=0.06992X-1.19640 Muddy bottom, No food Y=0.01615X+0.51150 Sandy bottom, No food Y=0.00495X+0.56150 4. When the predator is not present, $84\%$ of P. orientalis may survive. 5. Acanthogobius flavimanus is one of the predator of P. orientalis. 6. It is considered that the variation of water conditions of the pond, in which water had been exchanged 12 times per month, did not affect to the survival rate of P. orientalis.

• Korean Journal of Ichthyology
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• v.23 no.2
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• pp.135-144
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• 2011

Collections were made monthly using beam trawl from March 2005 to February 2006 in Gujora, and from June 2006 to May 2007 in Geoje Bay to investigate the species composition of Juvenile and Immature Fishes of both coastal areas. Fishes collected in the sandy shore of Gujora were 6 orders, 14 families, 20 species, 224 individuals, and 534.9 g in total. Favonigobius gymnauchen, Trachioncephalus myops, Pseudoblennius percoides, Sagamia geneionema, Repomucenus beniteguri, and Pseudorhombus cinnamoneus were mainly collected. These 6 species accounted for 83.9% of total individuals and 47.1 % of total biomass. On the other hand, fishes collected in Geoje Bay were 4 orders, 8 families, 14 species, 1,406 individuals and 1,899.7 g in total. Acentrogobius pflaumii, Platyce phalusindicus, Chasmichthy dolichognathus, Acanthogobius flavimanus, Gymnogobius urotaenia, and Synechogobius hasta were mainly collected. These 6 species accounted for 97.7% of total individuals and 96% of total biomass. The greatest numbers and biomass of fishes were collected in summer and the lowest in winter. In Geoje Bay, the number of species and individuals reached the peak in September and August, respectively. However, both species and individual numbers were highly fluctuated in Gujora.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.715-722
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• 2002

The monthly collected fish samples by crab pots were analyzed in order to study the species composition and seasonal variation of fish assemblage in the coastal water off Gadeok-do, Korea in 1998, During the study period, 49 species of fishes representing 26 families were collected, The dominant species were Conger myriaster, Sebastes inermis, Hexagrammos otakii, H. agrammus, Stephanolepis cirrhifer and Acanthogobius flavimanus. These 6 dominant species accounted for $67.1\%$ and $69.4\%$ in the number of individuals and biomass, respectively. The secondary importance species were Thamnaconus modestus, Takifugu niphobles, Rudarius ercodes, Dictyosoma burgeri, Sebastes longispinis and Epinephelus septemfasciatus. The highest number of species was collected in November, and the number of individuals and biomass were highest in March. But the lowest numbers of species and individuals were collected in July and the lowest biomass in September, Although the species diversity indices varied little monthly, the lowest value was recorded in August because of small number of species and predominance of 5. cirrhifer and T. modestus.

• 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.