• The Korean Journal of Zoology
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• v.7 no.2
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• pp.25-36
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• 1964

The present paper deals with the comparative study on phylogenic difference in the patterns of energy metabolism of brain slices of several vertebrate species by measuring oxygen consumptionwith glucose-6-phosphate, glucose-1-phosphate, glyceraldehyde-3-phosphate or glutamate as respiratory substrate employing Warburg's manometric method, by determination of the utilization rate of glucose using glucose-1-C14 by analyzing patterns of free amino acid distribution , and by histochemical determination using glucose-1-C14 by analyzing patterns of free amino acid distribution acid distribution , and by histochemical determination of glycogen contents. 1. Glucose enhances the oxygen consumption of brain slices of animals belinging to reptile, aves and mammalia while it shows a tendency to decrease that of animals belonging to pisces and amphibia. 2. Glucose-6--phosphate increase oxygen consumption more than glucose in every species examined, while glucose-1-phosphate and glyceraldehyde-3-phosphate increase that of Rana nigromaculata only . In general m, it appears that phosphosugars are more effective as a respiratory substrate to those species which have less endogenous respiration than to those having larger endogenous respiration. 3. Similar patterns of free amino acid distribution and the relative amount are found among the species and in every species examined glutamic acid is detected in the larges amount . ${\gamma}$-Amino butyric acid, glycine, alanine and aspartic acid are found in every species. 4. Ophicephalus showed less oxygen consumption than endogenous respiration when glutamate was added to the medium. When sodium fluoride was added, the oxygen consumption was some what increased . Such phenomenon wasnot found in the frog. 5. The result of histochemcial analysis of the brain showed that glycogen was abundantly present in the fish , amphibia , and especially in the reptile and that no distinctive grains of glycogen were found in the bird and mammal . From these facts, it may be supposed that anaerobic glycolysis as energy source dominates in fish and amphibia and aerobic respiration through the oxidation of glucose dominates in bird and mamal , the reptile occupying transitional position between these two categories. The way of obtaining energy for brain activity by the oxidation of glucose supplied from the circulating blood is seemed to be first acquired by reptile and the function is completed both in aves and mammal.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.153-158
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• 2004

The juvenile gobiidae, Tridentiger trigonocephatus were reared for 40 days under the salinity ranges between 0 and 33.6$\textperthousand$ to examine the effects of salinity on the survival, growth and oxygen consumption rates of the fish. Survival rates were significantly declined for the fish reared under 3.4$\textperthousand$, and daily growth rates were also reduced below 6.7$\textperthousand$ Body length and weight of gobiids reared below 6.7$\textperthousand$ were smaller than those reared above 13.4$\textperthousand$. Oxygen consumption rates in the salinity conditions $\leq$ 10.1$\textperthousand$ were significantly reduced with decreasing salinity. This study reveled that low salinity reduced survival, growth and oxygen consumption rates of the juvenile gobiids suggesting potential influence on the natural mortality of Tridentiger trigonocephalus in the estuarine areas where experience the extreme salinity fluctuations in Korean waters.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.310-318
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• 2001

In the large regulated Nakdong River, the Predation effect of juvenile fish on the zooplankton community was evaluated by gut and stomach analyses of fish in 1999. Juvenile fish of five species showed high density from May to early June when river discharge was low and water body became stagnant. During this period, large rotifers, Asplanchna spp. and Brachionus spp. declined and the decrease of cladoceran (Moina micrura and Bosminopsis deitersi) density was also obeserved. At this time, small rotifers including Polyarthra spp. reached maximum density. Gut analysis of fish demonstrated that small-sized juvenile fish (< 15 mm in total length)preferred large rotifers as well as cladocerans, while large sized fish (> 15 mm)selected only cladocerans. On the other hand, juvenile Micropterus salmoides of which size was larger than other juvenile fish consumed not only zooplankton but also other small juvenile fish. Based on these results, the decline of large rotifers and cladocerans during early summer in the river seems to be result of predation by juvenile fish. However, the period when juvenile fish maintained their high density was as short as one month and the decreased density of cladocera rapidly recovered as soon as juvenile fish became scarce. Such a short period of juvenile fish devel-opment in the river can be attributed to the consumption of juvenile fish by the young-of-the-year cohorts as well as adults of M. salmoides. The high trophic state of the river might permit the rapid recovery of the cladoceran community. The predation impact of juvenile fish in the Nakdong River seems to be affected by the existence of piscivore as well as high trophic status.

• The Journal of Fisheries Business Administration
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• v.28 no.2
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• pp.67-85
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• 1997

The subject of this study is limited to the market of producting and the analyzed the change of the supply structures, but the wide range of the study also contains the relationship present movement of consumption and the supply stuctures. To put it concretely, the present movement of the structre and the development of the market of producting are examined with the fisheries processing firms. The factors which dominate the structure of fisheries processing are; first, fisheries products as raw materials of processing; second, man-power; third, processing facilities and techniques; forth, a market where the products will be consumed. In particular, the conditions of supply of raw materials which are major factor have been worse and worse due to exhaustion of marine resources and so the capacity of fisheries production has been reduced. Furthermore, the conditions of manpower also are in trouble. Under the conditons, raw materials are imported largely and many companies try to make overseas enpansion for cheap manpower and raw materials. Particulaly, the relationship between consumption market and the structure of processing in a place of producton is analyzed newly. I try to show new logic that demands of consumption market are reflected strongerly to production with the development of consumption market and the rights of decision on the choice of raw materials and a processing item have been handed over to consumption market. In a word, I try to examined closely the new supply structure of fisheries products and the structure of consumption market through the analysis of the structure of processing in a place of production.

• Journal of the Korean Society of Food Culture
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• v.19 no.3
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• pp.273-284
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• 2004

This study is on the changing pattern of fish-and-shellfish uses during the last two thirds of Chosun period on the premise that they are influenced by development of fishing technology. With a literary approach, this paper researches how fish-and-shellfish production and consumption pattern changed, especially in relation to technological development of fisheries. First, we examine into the changes of fishery production. And next, we analyze the kind and cooking method of fish-and-shellfish in [Eum-sik-di-mi-bang](1670) and [Gyu-hap-chong-seo](1815). The analysis of two books revealed that there were significant differences in fish-and-shellfish uses. Because the two books were written with a gap of 145 years and the development of fishing technology and remarkable changes of fishery production affected on the fish-and-shellfish uses. Due to primitive fishing tools and skills, fresh-water and reverse-river-fish and shellfish had been caught in substantial amount until the middle ages of Chosun period. As a result, the availability of seafood were limited extremely even in the upper classes. These situations are evidenced by the analysis of [Eum-sik-di-mi-bang]. Only 12 kinds of fish-and-shellfish are described in [Eum-sik-di-mi-bang]. Most of the sesfoods is mollusc which is easy to catch. As for the salt-water fish, dried cod and dried herring were mentioned. Mullet, the reverse-water-fish, is used most frequently. Only one kind of 'Hoe', which needs extreme freshness, is described. This means that the use of fresh fish-and-shellfish was very limited to some kinds which could be caught near the village. As the netting fishery began to be developed in the 18th century, the production of some salt-water fishes, such as anchovy, shrimp, yellow corvina, pollack, and herring, had increased remarkably to make marine resources more available. Small fish, such as anchovy and shrimp were preserved as 'Jeot-gal' and sold nationwide. Therefore, 'Jeot-gal' and seafood could be used in Kimchi around this time and had a deep influence on the change of Kimchi in taste and nutrition. In [Gyu-hap-chong-seo], 33 kinds of fish-and-shellfish are described. Including cod and herring, 17 kinds of sea water fish and mollusc are mentioned. Some of these are consumed in fresh state, neither as dried nor as salted. Because the merchants promoted the transport of seafoods to other regions according to the growth of commercial economy. As a result the diet of the people could be enriched by the various seafoods.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.7
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• pp.157-164
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• 2020

As the consumption of fishery products continues to increase, aquaculture industry has emerged instead of fishing industry facing limitations of fish stock resources. Recently, smart fish farming industry has rapidly developed through convergence with 4th Industrial Revolution technology. Accordingly, it is important to derive a future model of smart fish farming platforms in order to secure the superiority of the aquaculture industry and the technology standard hegemony. In this study, the future direction of smart fish farm platform was derived through the analysis of environment related to politics, economy, society, and technology related to smart fish farming by applying PEST methodology of macro-environment analysis. It is expected that it will help the public and industrial circles in planning and implementing related projects by including the entire process of value chain of aquaculture industry of breeding, production, management and distribution, and by presenting advanced models based on artificial intelligence and digital twin.

• Journal of fish pathology
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• v.30 no.2
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• pp.97-105
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• 2017

Parasitic leeches could directly (through causing poor growth, anemia and wound in the fish) and indirectly (by predisposition of the fish to secondary bacterial and fungal infections) affects their hosts. In the present study, fishes that were attacked by leeches in natural and experimental environment were studied. Pathologic samples were obtained from damages at the site of leech bite, as well as kidney and liver of the fish. Histopathological examination revealed numerous lesions at the site of leech bite including tissue demolition, detachment at the site of leech bite in the epidermis of epithelial tissue in the skin, destructed nucleus in epithelial cells of the skin plus necrosis in the damaged skin and weak inflammatory penetration to acute necrotic damages along with piercing dermis layer. Pathologic lesions in the kidney included some changes such as proliferation by increasing glomerular cells and membrane cells in capillary vein of the kidney, blood cell necrosis in kidney with infiltration of white blood cells mainly mononuclear and less polymorphonuclear which are the symptoms of anemia due to blood feeding and sucking by leeches. There was also a chronic kidney infection probably originated from another part of body such as skin. Moreover, leeches caused hemorrhagic anemia due to blood consumption of the hosts, which led to observation of immature red blood cells. Also results showed that diseases induced by leeched in fish could be acute or chronic, which depends on size of fish, species of leech and severity of infection.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.1
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• pp.87-91
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• 2019

Effects of feeding frequency on the growth performance of juvenile starry flounder Platichthys stellatus were investigated. One thousand fifty fishes were distributed into 15 of 500-L flow-through tanks. Triplicate groups of were fed experimental diet with five feeding frequency (one meal every two days, one meal a day, two meals a day, three meals a day and four meals a day) for 9 weeks. Weight gain and specific growth rate (SGR) of fish fed two meals a day were higher than those of fish fed one meal 2 days and one meal a day, but not different from those of fish fed three meals a day and four meals a day. Feed consumption of fish fed two meals a day was not different from that of fish fed three meals a day and four meals a day. Feed efficiency (FE) and protein efficiency ratio (PER) of fish fed two meals a day were higher than those of fish fed all other diets, except for three meals a day. These results suggest that the optimal feeding frequency is two meals a day for the optimum growth performance of juvenile starry flounder under the experimental conditions.

• Journal of agricultural medicine and community health
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• v.37 no.4
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• pp.223-232
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• 2012

Objectives: The objective of this study was to identify the relationship between fish consumption and blood mercury levels in a sample of adult Koreans. Methods: The study subjects were 299 residents of Busan (male: 65, female: 234) and 185 residents of Namhae (male: 69, female: 116), South Korea. Demographic characteristics, current smoking, current drinking, fish consumption per week, past history of amalgam treatment, and residential district were recorded by trained interviewers in June and July, 2009. We considered a portion of fish to be equivalent to 70 gm weight, and calculated amounts of fish consumed per week. Using chi-square tests, t-tests, ANOVA, and multiple linear regression analysis, we estimated the relationships between blood mercury levels and amount of fish consumed per week and other factors. Results: The mean blood mercury level of our subjects was 6.61 ${\mu}g/L$, higher than the criterion defined by the United States Environmental Protection Agency (EPA) (5.8 ${\mu}g/L$). In multiple linear regression analysis, residential district and amount of fish consumed per week were associated with blood mercury levels. However, marital status, current drinking, and gender, and age were not associated with blood mercury levels. Conclusions: In conclusion, we suggest the implementation of systematic and periodic population-based studies to decrease the risks of mercury poisoning among South Koreans who consume fish as a regular part of the diet.

• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.120-131
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• 2022

Microcystins (MCs) are cyano-toxins mainly produced by cyanobacteria in the genera of Microcystis, Anabaena, and Oscillatoria. The concentrations of MCs in the water bodies and fish tissues taken from the four weirs (Ipo, Gangjeong-goryeong, Baekje, and Juksan) in the four main rivers in Korea, and the health risk of human due to consumption of toxin-detected fish was examined. The maximum values of MCs concentration in the water samples were as follows: Juksan (3.261 ㎍ L^-1), Gangjeong-goryeong (1.014 ㎍ L^-1), Baekje (0.759 ㎍ L^-1), and Ipo (0.266 ㎍ L^-1) weirs. The MC-RR concentration was the highest among the MCs, and MC-YR was not detected. MCs of 0.222~9.808 ㎍ g^-1 dry weight were detected in the liver of 3 out of 215 fishes of 16 species, and below the detection limit in muscle. As a result of comparing the feeding characteristics of the collected fishes and toxin concentrations in water and fish tissue, it was concluded that the biomagnification of MCs through the food chain did not occur. It was judged that there was no health risk due to the consumption of the fish detected the toxin, based on the amount of the fish intake of the Korean people and the allowable daily intake of MCs. However, in order to reduce the health risk due to MCs, further studies should be conducted to analyze the concentration of MCs contained in fish tissues collected at various times in the area dominated by harmful cyanobacteria to obtain data on the exposure of MCs due to fish consumption. In addition, it is necessary to establish the management guidelines for MCs in fish tissues.