• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.57-66
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• 2008

The purpose of this study was to establish biomonitoring method for the assessment of the health of fish species in agricultural reservoirs polluted from various environmental contaminants. The ichthyofauna and fish community were investigated in the AsanHo and NamyangHo from September to November 2007. We measured abundance, size distribution, biomass, the number of fish with external and internal lesions, organosomatic index of the fishes collected in the AsanHo and NamyangHo. Dominant species were Lepomis macrochirus, Carassius auratus and the highest biomass were found in Cyprinus carpio, Carassius auratus in the AsanHo and NamyangHo, respectively. The composition of age in the population of Carassius auratus in the AsanHo and NamyangHo was stabled by size distribution analysis. The sex ratio of Carassius auratus were 1:0.36, 1:0.52 as female: male ratio in AsanHo and NamyangHo, respectively. The GSI of were 4.30, 1.69 of female and 1.45, 1.70 of male in AsanHo and NamyangHo, respectively. Most carp were 10-70 cm long in the AsanHo and 20-50 cm in the NamyangHo. The sex ratio of Cyprinus carpio were 1:0.42, 1:0.59 as female: male ratio in AsanHo and NamyangHo, respectively. The GSI of were 0.16, 3.46 of female and 0.93, 2.37 of male in AsanHo and NamyangHo, respectively. Of the 227 fish examined, 1.8% had some type of external lesion in AsanHo and 10% in NamyangHo. Overall, HAI scores ranged from 10-60 and HAI scores of AsanHo relatively lower than that of NamyangHo.

• Korean Journal of Ichthyology
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• v.32 no.3
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• pp.130-135
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• 2020

Male gonadal development of the yellow catfish, Pseudobagrus fulvidraco, one of the most popular fish species in Korean aquaculture performance, was investigated by histological observation of monthly collected specimens to make comparisons between wild and cultured individuals. Their reproductive cycle was classified into the successive developmental stages as follows: a growing stage (April), a spawning stage (May), a degeneration stage (June to July), and a resting stage (August to October) in the wild and outdoor-cage individuals; a growing stage (April to June), a spawning stage (July to August), a degeneration stage (September), and a resting stage (October) in the indoor-cage ones. Values of gonadosomatic index (GSI) of wild and outdoor cages peaked in May, followed by a sudden decline in August~September and June~August, respectively. In contrast, GSI values of the indoor-cage individuals peaked in September and were followed by a sudden drop. Remarkable seasonal variation in condition factor (CF) was undetectable, peaking in June in the wild-cage individuals and November in the wild ones. Overall, our results suggest that it is suitable to use the male of the outdoor-cage individuals for artificial fertilization and that it is efficient to perform artificial fertilization in May, such as reproductive cycle of wild.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.260-266
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• 2016

We determined the morphologic characteristics (body weight and abdomen inflation degree) of the mother fish of sevenband grouper, Epinephelus septemfasciatus producing the healthy eggs. Experimental fish were chosen from the reared fish in the sea cage for 6 years. The fish were divided into four size groups by body weight: 4.0~5.0, 5.0~6.0, and 6.0~7.0 kg and four stages (I~IV) by the abdomen inflation degree. After hormone treatment, we observed the ovulation amount of induced eggs, rate of buoyant, fertilization, embryonic survival, and hatching. Egg and oil globule diameter was measured. In order to observe gonadal development, we calculated gonadosomatic index (GSI) and conducted its historical analysis. The ovulation occurred from all experimental fishes over 5.0 kg. The rate of buoyant, fertilization, and embryonic survival was the highest in 6.0~7.0 kg. Hatching rate was the highest in 5.0~6.0 kg. Stage I and II did not induce ovulation. GSI was $0.31{\pm}0.10%$ in stage I, $0.74{\pm}0.25%$ in stage II, $4.68{\pm}0.40%$ in stage III and $6.86{\pm}0.12%$ in stage IV. The rate of buoyant, fertilization, embryonic survival and hatching was the highest in stage III.

• Journal of Life Science
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• v.21 no.3
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• pp.406-411
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• 2011

To investigate the effects of short-term treatment with tri-n-butyltin chloride (TBTCl) and bisphenol A (BPA) on the reproduction of striped field mice, the mice were intramuscularly injected with TBTCl or BPA immediately before the reproductive season and examined in the reproductive season after keeping them for 4 months. As a result, there were no differences between the control and the compound-treated groups regarding body weight in both sexes, the residual levels of the compounds in the adult males, and the gonadosomatic index (GSI) and the histological structures with LM and EM of the testes and epididymides in both the adult and young males. The infant mortality and abortion rate, however, were high in the TBTCl-treated groups and BPA-treated groups respectively, compared to the control group. Conclusively, it was suggested that short-term treatment with TBTCl or BPA in mice in the non-reproductive season might have inhibited the development of the uterine embryos or fetuses, although it did not induce accumulations of these compounds or affect the reproductive organs of adult and young (F1) males.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.1
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• pp.17-25
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• 1998

A fisheries biological study on the hairtail (Trichiurus lepturus LINNAEUS), which was collected from Cheju City, Hanrim, Sungsanpo and Seogwipo in Cheju Island, was carried out from June through December In 1992. GSI of the hairtail maintained relatively high from June to September, and then it began to decrease in October and remained low until December. The maturation and spawning period was between June and October, and the major spawning occurred in August. The hairtail turned out to be a multiple spawning species which spawn two or three times In a single spawning season. During the spawning season the number of females was greater than that of males, whereas the sex ratio was almost 1 : 1 during the rest of the season. Fecundity estimated from various sizes of the hairtail ranged from 12,821 to 125,876. The bigger the snout anal length and body weight of the hairtail was, the more eggs it possessed.

• Korean Journal of Ichthyology
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• v.18 no.2
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• pp.87-96
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• 2006

Reproduction and organ system of the oily bitterling, Acheilognathus koreensis in Isa stream were investigated by means of histological methods. Sex ratio was observed 1 : 1 in female to male. The gonadosomatic index (GSI) of the female showed two peak in December and April. The ovipositor length index (OLI) represented irregular change. From the histological analysis of the organ system, epidermal atrophy and hyperplasia of pigment cell were observed in the skin. Epithelial layer lifting of the lamella and bifurcation of the filament were observed in the gill. Also histological changes as congestion, cytoplasmic degeneration of hepatic cell, glomerular dilatation, hyaline droplet degeneration of renal tubule epithelium and pycnosis of interstitial cell were identified in the liver and kidney, respectively.

• Korean Journal of Ichthyology
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• v.23 no.4
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• pp.300-304
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• 2011

The reproductive characteristics of Chaenogobius gulosus was examined using 333 specimens collected monthly between October 2008 and September 2009 in the coastal waters of Tongyoung, Korea. Specimens ranged from 2.0 to 12.6 cm in standard length (SL). The gonadosomatic index (GSI) of females was highest in February and decreased until April, with the spawning season lasting from December to April. The monthly ratio of female to male did not significantly differ (${\chi}^2$-test, p>0.05). The size at 50% maturity for females was 7.9 cm SL. Fecundity ranged from 1,112 to 6,059 eggs, with a mean of 3,011 eggs.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.53-53
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• 2003

참가자미, Limanda herzensteini는 가자미목 (Pleuronectiformes), 가자미과 (Pleuronectidae)에 속하며, 우리나라의 동해, 일본의 세토내해 이북, 중국 및 사할린 근해에 분포하는 어종이다. 본 종은 연안정착성 어종으로 동해안에서 낚시 및 저인망 어업에 의해 어획되는 산업적 가치가 큰 고급어종이며, 저수온에 강하여 한류성 해역에서의 양식 가능성이 매우 높다고 할 수 있다. 또한 최근에는 참가자미의 자원량 감소가 두드러지고 있으므로 자원증강이 절실히 요구된다. 이 연구에서는 주 어획지역인 강원도 주문진 인근해역에서 1998년 9월부터 1999년 10월까지 자연산 참가자미의 연간 생식소중량지수의 변화를 조사 하였으며, 조직학적 조사에 의한 생식소 발달과정과 생식주기를 밝혔다. 정소는 정소엽 형태이며, 각각의 정소엽은 여러개의 소낭구조를 가진다. 각 소낭내의 생식세포들은 같은 단계의 발달상태를 보인다. 난소는 원추형의 낭상으로 체강벽에서 연결되는 난소간막에 의해 부착되어 있으며, 내부는 결체성 조직인 다수의 난소박판으로 구성되며, 이곳에서 난원세포가 유래한다. 수컷의 GSI는 1월에 가장 높았으며, 암컷의 GSI는 3월에 가장 높은 값을 보였다. 생식주기는 성장기(6~9월), 성숙기(10~12월), 완숙 및 산란기(1~3월) 그리고 회복 및 휴지기(4~5월)로 나눌 수 있었다. 난모세포의 발달양식은 난군동기발달형에 속하였다.

• Development and Reproduction
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• v.7 no.1
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• pp.23-28
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• 2003

The seasonal reproductive cycle of the female honeycomb grouper, Epinephelus merra, inhabiting Chuuk was examined by histological observations of the ovaries. The gonadosomatic index (GSI) began to increase in February and peaked in March. Histological observations revealed many oocytes laden with yolk in the ovaries from March to April. From June to January, the ovaries were occupied by immature oocytes. These results suggest that the reproductive season of E. merra in Chuuk is from March through April.

• Journal of Korean Society for Geospatial Information Science
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• v.7 no.2 s.14
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• pp.93-100
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• 1999

Forest fires have been threats to natural resources, endangered species, properties and even to human lives. Efficient management of forest fires requires a complete understanding of the environmental and human related activities, as well as complicate spatial relationships among them. A geo-spatial information system(GSIS) is an appropriate method of being able to mapping and to analyze the spatial data for forest fires. Therefore, this study is to provide and classify the terrain, vegetation, life environment soil and geology factors, and to analyze spatial distribution for forest fire areas by applying the GSIS and the Remote Sensing technology. On the other hands, causes of increasing numbers of forest fires being occurred after In were assessed by comparing the normalized difference vegetation index((NDVI).