• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.137-146
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• 1982

Histological study of eel was carried out to determine the effect of drying on muscular tissue and fat movement. The results are as follows: (1) Changes of muscular tissue during drying may he divided into two stages early and late. In the early stage there was apparent dehydration of connective tissue while in the late stage muscle fibre dehydration appears to occur. (2) Movement of fat during drying depends upon division and contraction of the myocommata caused by inner structural changes. This phenomenon appeared to be more apparent in the late rather than the early drying stage.(3) After freeze-drying traces of ice crystals were detected around the muscle cells. These ice crystals remained even after rehydration. (4) When muscular tissue was heated the connective tissue melted while muscle fiber dehydrated and solidified.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.25-32
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• 1969

The estimated annual catch of river fishes in the lower part of the Naktong River was derived from the questionnaire, as a part of the fundamental investigation which was carried out for the development of fisheries In that region during the period of May 1967, to June 1968. The data were submitted by fishermen, and the area covered for the present investigation is shown in Fig.1. The annual catch of the region was estimated to be about 500 tons, excluding the mussel Cerbicula elatior. Prussian carp Carassius carassius was the largest in amount followed by com-mon carp Cyprinus carpio, and then goby Synechogobius hasta, Japanese eel Anguilla japonica, mullet Mugil cephalus, ect. and in that order. Major species of the fishes of this region belong to the carp family Cyprinidae, its species counting 23 from the collection during the observation period, and the total number of species was 40, these belonging to 14 families. But occasional severe drought heavily increase the salt content of the region, and at that time the major catch of fish becomes marine fishes such as Harengula zunasi, Clupanodon Punctatus, etc.

• Journal of Environmental Science International
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• v.18 no.9
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• pp.1001-1010
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• 2009

To investigate the ichthyofauna and habitat type of the fish in Tamjin River system, Korea, fishes were collected with cast net ($5{\times}5\;mm$, $8{\times}8\;mm$) and dip net ($4{\times}4\;mm$) at eight stations seasonally during five years from 2000 to 2004. 56 species belonging to 18 families were collected and 15 Korean endemic species( 26.8%) were investigated. While Coreoperca kawamebari was occurred at every station, the number of individuals and composition were decreased. Anguilla marmorata was not collected and the exotic species didn't appeared. Dominant species were Zacco platypus(34.2%), Squalidus gracilis majimae (9.4%), Microphysogobio yaluensis(8.1%), Zacco temmincki(6.8%) and Acheilognathus lanceolatus(5.1%). The surveyed stations were clustered into 3 groups: up stream, main stream and estuary. With the cluster analysis using the relative abundance of major fishes at each habitat, fishes were separated into 5 habitat types: U (upstream type), UM (up and main stream type), M (main stream), ME (main stream and estuarine type), and E (estuarine type).

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.297-303
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• 2005

The analysis of fish community structure in the Peace Dam, Korea, was investigated from April 2003 to September 2004. Eight families and 31 species were collected during the period surveyed. Korean endemic species were 13 and the relative abundance was 41.9% of the total, along with Hemibarbus mylodon, Acheilognathus yamatsutae and Coreoleuciscus splendidus. Dominant was Hemibarbus labeo (14.1%) and subdominant species was Zacco temmincki (13.7%). Also, Z. platypus (11.9%), H. longirostris (9.3%), and Siniperca scherzeri (8.1%), were numerous. The biomass of collected fishes were H. labeo (24,278 g), S. scherzeri (19,487 g), Anguilla japonica (10,400 g), Cyprinus carpio (8,418 g), and Carassius auratus (4,020 g), According to the community analyses, the artificial reservoir with in the Bukhan River system were divided into 2 groups by unweighted pair-group method analysis (UPGMA), and it revealed that the community structure in Peace Dam was similar to those in Soyang and Paro Reservoirs.

• Animal cells and systems
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• v.16 no.5
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• pp.415-424
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• 2012

Four species of ophichthid leptocephali were identified using 12S rDNA sequences, and their morphological descriptions were first provided based on six individuals (S1-S3,M1, and E1-E2) collected from the East Sea and the Korea Strait between September 2008 and October 2010. Mitochondrial 12S rDNA 859-861 base pairs of ophichthid leptocephali were compared with those of 16 ophichthids adult and 2 outgroups (Anguilla japonica and Conger myriaster). Leptocephali of S1 and E1 were very closely clustered with adult of Scolecenchelys borealis (D=0.002) and Echelus uropterus (D=0.000), respectively. However, leptocephali of S2-S3 andM1 were slightly far clustered with leptocephalus of S1 (D=0.006) and adult of Muraenichthys gymnopterus (0.034), respectively. We believe that S1 and E1 are S. borealis and E. uropterus, respectively, in which the former is unrecorded species in Korea. However, S2-S3 and M1 may be undescribed species belonging to genus Scolecenchelys and Muraenichthys, respectively, because total numbers of myomeres for S2-S3 (148-158) and M1 (151) were not consistent with total numbers of vertebrae or distribution for any adult of Scolecenchelys spp. and Muraenichthys spp. in the world. We propose the new Korean name 'Dong-hae-mul-baem' for S. borealis.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.111-119
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• 2004

The ichthyofauna and community structure in Lake Paro, Korea, was investigated from December 2002 to september 2003. Buying the surveyed period 45 species belonging 12 families were collected. There were 15 Korean endemic species 33.33％, including Hemibarbus mylodon, Aeheilognathus yamatsutae nnd Ooreoperca hem. Dominant species were Zacco platypus (72.41％) and subdominant species were Hemibarbus labeo (9.75％). Also, Opsariichthys uncirostris amurensis (5.98％), Zacco temmincki (2.42％), Rhinogobius brunneus (2.01％) and Hypomesus olidus (0.88％) were numerous. The biomass of collected fishes were Zacco platypus (82,803.15 g), Hemibarbus labeo (32,942.63 g), Opsariichthys uncirostris amurensis (27,482.39 g), Cyprinus carpio (6,502.87 g), Anguilla japonica (3,022.15 g) and Siniperca scherzeri (2,711.05 g). Of the 10 introduced fishes in Lake Paro Cyprinus carpio (Israeli type), Carassius cuvieri, Micropterus salmoides and Lepomis macrochirus were originated form foreign countries but Anguillta japonica, Hemiculter eigenmanni, Hypomesus olidus, Oncorhynchus masou mason, Chaenogobius urotaenius, Rhinogobius giurinus were introduced from other native river systems.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.4
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• pp.179-186
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• 1974

The followings are some results obtained from a series of experiments for the culture of eels from the elver stage in the laboratory from April 1973 to June 1974. 1. The optimum temperature turned out as 30t in the early stage culture. 2. The exponential curve of growth rate for a ten day period at the temperature between $20^{\circ}C$ and $30^{\circ}C$ was represented by the following equation: $$R=0.0056296\;T^{1.80740}$$ 3. The elvers and small eels that were kept improperly for a long time before this experiment also showed the same growth rate, compared with other healthful eels captured directly from the estuarine areas. 4. Those that showed retarded growth among a group of eels during the culture recovered the normal growth rate if graded out and kept in the other aquarium. 5. Feeding rate was not affected when the content of ammonia was less than 5 ppm, but it decreased by half when the content exceeds 6 ppm. 6, The elimination of fecal stuffs and uneaten dispersed feed was very important for the maintaining the water in quality.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.499-505
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• 2011

The fishing grounds of Korean large-pair trawlers have shifted since exclusive economic zones (EEZs) were established in a fisheries agreement involving countries neighboring Korean waters. The distributions of marine ecosystems and fisheries resources have been changing with environmental changes such as global warming and with the shift in species targeted as a result of changes in fishing technology and fishing gear. This study analyzed variation in the species assemblages caught in Korean waters by large-pair trawlers as a result of these geopolitical and environmental changes. The data used in this study were obtained from the Fishery Production Statistics of Korea and the Port Sample Survey of the National Fisheries Research and Development Institute (NFRDI) from 1990 to 2007. Hierarchical clustering analysis (HCA) and correspondence analysis (CA) were used to explore the characteristics of the catch-species composition. The overall variation in the species composition of the catch of Korean large-pair trawlers showed that the proportions of croaker Johnius grypotus, small yellow croaker Larimichthys polyactis, eel Anguilla japonica, and blue crab Portunus trituberculatus decreased, whereas those of hairtail Trichiurus lepturus, Spanish mackerel Scomberomorus niphonius, anchovy Engraulis japonicus, and common squid Todarodes pacificus increased in Korean waters over the 18-year period. The results of the HCA of the annual catch data by species showed four different distributions of fish species according to year. Results of the CA showed that the species assemblages differed between the 1990s and 2000s.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.2
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• pp.78-84
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• 2006

A high performance liquid chromatography assay method for spiramycin in fish muscle was developed. The developed method was evaluated and validated by monitoring spiramycin in olive flounder (Paralichthys olivaceus), black rock fish (Sebastes schlegeli) and in live conger eel (Anguilla japonica) in fish farms and distribution centers. Using the developed method, the recovery rate was up to 82.4-88.8%, which was higher than that of conventional methods (77.6-87.1%). In particular, the proposed sample treatment protocol was suitable for use with fish samples to remove low molecular weight materials and pigments that could interfere an accurate analysis. The prepared stock solution was very stable, and it remained chemically stable for 5 weeks at $4^{\circ}C$. The performance limit of the developed method for spiramycin acid in fish muscle was 0.05 ppm. One hundred thirty-four fish samples including olive flounder, black rock fish and live conger eel were analyzed to evaluate the overall efficiency of the modified method and to monitor the actual condition of spiramycin usage in fish farms. Olive flounder and black rock fish were collected from fish farms in coastal areas of Korea, and live conger eels were purchased from a fish market in the Busan area from September 2001 to March 2002. According to the overall performance of the developed method, it was considered suitable for the monitoring of spiramycin in fish muscle. The suggested method of analysis for spiramycin in fish muscle is registered in the Korean Official Methods of Food Analysis and is currently tieing utilized for fishery products inspection by the Korea Food and Drug Administration and the National Fisheries Products Quality Inspection Service.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.1
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• pp.1-6
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• 2008

The changes in osmolality and the gene expression profiles of prolactin (PRL) and growth hormone (GH) with rapid changes in salinity were compared in the eel (Anguilla japonica), crucian carp (Carassius carassius), and masu salmon (Oncorhynchus masou). Fish stocked in freshwater (FW) were abruptly transferred to experimental tanks containing FW, 50% seawater (50% SW), or 100% SW (SW). Blood samples and pituitary glands were collected 2 and 24 hrs after the exposure. No mortality was observed in SW eel (n=6), whereas all of the crucian carp (n=6) and two masu salmon (n=6) exposed to SW died after land 24 hrs, respectively. The PRL mRNA levels of the eel and masu salmon decreased in 50% SW and SW compared to those of the fish kept in FW after 24 hrs, whereas the PRL levels of crucian carp were higher in 50% SW than in FW. Unlike the PRL mRNA levels, the GH mRNA levels of the eel did not differ significantly among three different salinities, while the GH mRNA levels of crucian carp and masu salmon increased significantly in 50% SW and SW after 24 hrs. The serum osmolalities increased marginally in the eel and masu salmon in 50% SW at 24 hrs (19% and 9%, respectively), whereas those of crucian carp increased abruptly in 50% SW (50% increase). These results suggest that the synthesis of PRL and GH is important in relation to the osmoregulatory system with environmental changes in salinity.