• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.280-281
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• 2000

담수산 rotifer, Brachionus calyciflorus는 담수산 어류 종묘생산시 가장 널리 이용되는 초기 먹이생물로 이용이 가능하며 특히, 입이 작은 열대 관상어의 먹이로 이용되고 있다. Rotifer의 생식은 처녀생식과 유성생식을 교대로 하는 종으로색 유성생식에 의해 형성된 내구란은 종 보존용, 대량배양시 seed로 쉽게 이용될 수 있으며 환경 독성학의 실험생물로 많이 이용되고 있다. 특히 최근 해수산 rotifer, Brachionus plicatilis 내구란을 대량생산하여 Artemia cyst처럼 간편하게 부화시 어류에게 직접 먹이로 공급할 수 있는 기술 수준에 도달하였다. (중략)

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.279-286
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• 1996

Cultivated tilapia (Oreochromis niloticus) in the fresh water were acclimated to the sea water to improve palatability of the fish meat. Physicochemical properties in the rigor mortis of those fish meats were investigated during storage at $0^{\circ}C,\;10^{\circ}C\;and\;20^{\circ}C$. The faster onset of rigor mortis was occurred in acclimated meat than fresh water cultivated meat. Both meats stored at $0^{\circ}C$ showed faster figro mortis than at $10^{\circ}C\;and\;20^{\circ}C$. Significant difference was not observed between the breaking strength and the rigor index. The breaking strength reached maximum over 12hrs after death and then gradually declined, and the rigor index was slowly increased and reached maximum over 18hrs after postmortem. Low temperature and acclimation to the sea water affected the degradation of adenosine triphosphate (ATP), accumulation of inosine monophosphate (IMP) or lactate. These results suggest that the palatability of tilapia muscle cultivated in the fresh water could be improved by acclimation to the sea water which induces the prerigor at the early state of postmortem and the physical changes of fish muscle.

• Korean Journal of Ecology and Environment
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• v.42 no.3
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• pp.394-403
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• 2009

The fish fauna and community structures were investigated at 15 stations in the midupper region of the Seomjin River watershed from August in 2008 to April in 2009. During the studying period, 42 species belonging to 11 families were collected. Dominant family in the all sites was Cyprinidae (28 species, relative abundance: 66.7%) during the study. Total of 42 species (primary freshwater: 40 species, peripheral freshwater: 2 species) were found with the primary freshwater fishes being the highest. Dominant species was Zacco platypus (22.3%), and subdominant species was Coreoferea herzi (10.8%). Also, Pseudogobio esocinus (9.0%) and Carassius auratus (5.8%) were numerous. There were 17 Korean endemic species (40.5%), including Rhodeus ocellatus, Acheilgnathus koreensis, A. somjinensis, Coreoleuciscus splendidus and Sarcocheillichthys variegatus wakiyae. Among them, Acheilgnathus somjinensis was identified for designation required to protect under a wildlife category. In conclusion, we could define that the Seomjin River watershed has a very good water conditions as habitat of fish.

• River and Culture
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• v.8 no.3
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• pp.86-90
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• 2012

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.466-469
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• 1999

Cladocera are important food organism for seed production of finfishes. freshwater cladocera such as Daphnia and Moina are well known food organisms for the larval rearing of freshwater fishes and are easy for mass culture. However, mass culture technique for marine cladocera are not yet developed, The only mass produced food organisms available these days for the larval production of marine finfishes are rotifer and Artemia. An estuarine cladoceran, Diaphanosoma celebensis, has a high possibility of being used as a food organism for the larval rearing of marine finfishes because this species is much easier to mass culture than marine ones. Therefore many studies are needed for this species. In this study, the effects of the volumes of culture container, 40, 1,500 and 15,000 ml, on the stable production of this species were tested and results are as follow: The maximum densities of this species in each of the culture volumes were reached after 14 days in 40 ml, 12 days in 1,500 ml, and 21 days in 15,000 ml with values of 3.4 $\pm$ 0.4, 14.2 $\pm$ 2.1 and 2.5 $\pm$ 1.6 per ml, respectively. The relative population growth index (RPGI) was stable in the culture volume of 1,500 ml. Moreover, possible harvesting number(individual/ml/day) was much higher in the 1,500 ml container than the other culture volumes. Therefore, optimum culture volume among the tested volumes for mass production of this species was 1,500 ml.

• Korean Journal of Ecology and Environment
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• v.40 no.3
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• pp.449-458
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• 2007

Fish community and its temporal-spacial variation in the Lagoon Hwajinpo, Korea were seasonally investigated with different types of fishing gears from November, 2005 to August, 2006. Total 35.812 fishes caught during the period were belonged to 24 families 37 species. Dominant species was H. nipponensis(60.8%), T, hakonensis (19.8%), and K. punctatus (5.5%) ana these species were peripheral freshwater fish. Among 37 species, primary freshwater and seawater fish were 8 species (21.6%), respectively and peripheral freshwater fish were 21 species (56.8%). Total biomass of collected fish was 279.3kg, and biomass of each species was T. hakonensis 152.9 kg, H. nipponensis 40.0 kg, K. punctatus 31.4 kg and C. haematochelius 25.3 kg, respectively. Hence, productivity of the Lagoon Hwajinpo was much higher than those of inland reservoirs. The aspect of community classified by surveyed period was changed according to the 'Breaking-sandbar', but some of peripheral freshwater fish populations made stable community in their life cycle in the lagoon. In conclusion, the Lagoon Hwajinpo seems to be maintained more natural ecosystem better than other lagoons in Korea. Therefore, the findings provide consideration of the management and restoration for this lagoon and others through the continuous observation and monitoring in future.

• Parasites, Hosts and Diseases
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• v.33 no.4
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• pp.305-312
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• 1995

A species of metacercariae recovered from the fresh-water fish, collected from Kaumji (Pond), Kaechonji (Pond) and Ssanggyechon (River), Uisong-gun, Kyongsangbuk-do, Korea, was identified as Clinostomum compzcnatum by morphological observation and experimental infection to chicks. The excysted metacercariae, tongue-shaped and progenetic, were 3.28-4.27 mm in length and 0.94-1.46 mm in width. The adult flukes recovered from the chicks four days after infection were 4.20-4.86 mm long and 1.14-1.49 mm wide. Twelve species of the fresh-water fish were found to be infected with the metacercariae. The infection rate ranged from 1.6% (Zacco temminkii) to 88.9% (Acheilognathus rhombec and Microphwsogobio voluensis) . The intensity was highest in Cnrqssius curatus (13.0/fish infected) and the abundance (relative densityl was highest in A. rhombea (7.8/fish examined). This survey demonstrated for the first time the source of human infection by C. complnnntum in Korea.

• Journal of Aquaculture
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• v.19 no.1
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• pp.14-18
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• 2006

The objective of this study was to evaluate food value and profitability of black porgy (Acanthopagrus schlegeli) cultured in freshwater. In fish flesh, muscular hardness of black porgy reared in freshwater $(9210{\pm}1215g/cm^2)$ was slightly lower than those of fish in seawater $(9987{\pm}6549g/cm^2)$, but there was no significant difference. Also, there was no difference between muscular strength of fish reared in freshwater and seawater. When the flesh qualities of black porgy reared in freshwater was compared with those of fish reared in seawater through the questionnaire, there were no significant differences between fish reared in freshwater and seawater in appearance, texture, taste and flavor. For 10 months of black porgy culture in fresh water, the gross profit in culturing from juvenile (5.5 g) to adult size (100g), and from adult to marketable size (400 g) were 24,000,000 won (30.0%) and 53,870,000 won (36.9%), respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.2
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• pp.77-83
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• 1981

Four-day bioassay method was used in this study to find out toxicity levels of DDT and PCP. From this study it was found that M. chrysophekadion was the most sensitive to DDT with a 96 h-TL sub(m) value of 0.0044 mg/l followed by P. Sutchi with a 96 h-TL sub(m) value of 0.0056 mg/l, and the most resistant was C. Siamensis with a 96 h-TL sub(m) value of 0.0133 mg/l. In the case of PCP, it was also found that M. Chrysophekadion and P. Sutchi were the first and second most sensitive to PCP with a 96 h-TL sub(m) value of 0.065mg/l PCP and 0.125mg/l PCP respectively, as in the case of DDT study. T. Nilotica was found to be the most resistant to PCP with a 96 h-TL sub(m) value of 0.264mg/l PCP. The resistant power of fish to pollution varies with the species of fish and the types of pollutants. In order of decreasing sensitivity of fish to DDT based on TL sub(m), the following sequence is obtained M. Chrysophekadion, P. Sutchi, T Nilotica, P. Gonionotus, K. Bicirrhis, L. Bicolor, C. Carpio, R. Heteromorpha, C. Siamensis while in the case of PCP, M. Chrysophekadion, P. sutchi, L. Bicolor, K. Bicirrhis, P. Gonionotus (R. Heteromorpha, R. Trilineata), C. Siamensis, C. Carpio, T. Nilotica.

• Journal of agricultural medicine and community health
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• v.26 no.2
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• pp.161-179
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• 2001

Recent patterns of infections with digenetic larval trematodes from fresh-water fish were studied in five locations of the river Taega during the period from October, 1998 to September, 2000, and compared with the data reported previously in the same river. The fish were collected using following techniques ; fishing, throwing a castnet, and using a bait of crushed oil cake in a transparent plastic bowl. Of 19 species of fish examined, eight species of encysted larvae, Clonorchis sinensis, Cyathocotyle orientalis, Centrocestus armatus, Clinostomum complanatum, Exorchis oviformis, Metagonimus species, Metacecaria hasegawai, and Metorchs orientalis, and two kinds of undetermined cyst A and C were found. The encysted larvae of Exorchis oviformis were found most frequently from 12 species of fresh-water fish, followed by Metacercaria hasegawai larvae from 9 species, the cyst of Clonorchis sinensis and Cyathocotyle orientalis from 7 species, Centrocestus armatus from 3 species, Clino- stomum complanatum from 2 species, and Metorchis orientalis from 1 species. The infection rates of fish with Clonorchis sinensis larvae were lower than those reported in 1993, whereas their intensity of infection was found lowered in 3 species, Pungtungia herz I, Saurogobio dabry i, and Squalidus jap onicus coreanus. The infection rates and intensity of 6 species of fish with Metagonimus sp ecies larvae were lower than the results in 1993, while the rates in several species of fish with Exorchis oviformis rather higher. The encysted larvae of Cyathocotyle orientalis, Metacercaria hasegawai, and Metorchis orientalis showed variations in infection rates of fish in 1993 and in the present study. However, It was impossible to compare the infection rates for the encysted larvae on the scales, fins and tail as they varied so considerably in both 1993 and 2000 surveys. This study indicate that the rate of infection with digenetic larval trematodes in fresh-water fish was still relatively high in the river Taega, and the metacercarial burden in the fish varies greatly by different fish in 1993.