• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.429-436
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• 2013

Churyeong Stream flows 37km from the mouth of Lake Okjeong and is impeded by many weirs that hamper the active movement of land-locked sweet smelt fish (Plecoglossus altivelis) that ascend and descend between the lake and the upper stream. In late December 2006, a fishway was constructed in a weir of the lower reach of Churyeong Stream, where juveniles begin their ascent to mature upstream. At 13 sites along the stream from April to October 2007, we investigated the effects of the newly constructed fishway on sweet smelt growth. After construction of the fishway, juvenile sweet smelt were able to migrate freely upstream, something that had previously only been possible when the weir was in flood. The body size of mature sweet smelt collected during the spawning season in September 2007 was greatly increased compared to previous seasons, measuring an average of $163{\pm}21.5mm$ in standard length. These measurements were 13mm, 20mm, and 57mm longer than body length averages for mature sweet smelt collected in 2006, 2004, and 2005, respectively. Therefore, it is likely to be necessary for the construction of fishways on streams and rivers containing land-locked sweet smelt populations to increase average body sizes and viability.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.99-100
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• 2001

Although cultured sweet smelt production recently have been rapidly increased from 89 metric tons (M/T) in 1997 to 500M/T In 1999 in Korea, wild fish have been still used as broodstock for cultured fish seed. This is considered due to having higher sperm and e99 qualify in wild fish broodstock than cultured fish. However, capturing a number of wild sweet smelt broodstock might lead to decreasing of the production of wild fish, In truth, of which production has been greatly decreased so that a number of artificial juvenile have been stocked some rivers in Korea. (omitted)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.97-98
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• 2001

Alpha-tocopherol (alpha-Toc) is a classical lipophilic antioxidant well known as a scavenger of free radicals in a hydrophobic milieu. The primary function of alpha-Toc is to stabilize cellular and subcellar membrane by preventing peroxidative damage of structural polyunsaturated fatty acids (PUFA). The characteristic aroma of sweet smelt Precoglossun altivelis is known as oxida breakdown products of PUFA ironically. (omitted)

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.163-170
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• 2001

The effect of perilla oil added in diet on the biochemical properties of cultured sweet smelt, Plecoglossus altivelis, was investigated. The cultured fish were fed two different diets for 8 weeks; a control diet was a commercial diet, which was low in the content of docosa­hexaenoic acid (DHA, 22: 6n-3) and eicosapentaenoic acid (EPA, 20: 5n-3) less than approximately $2\%$ (CO group) and an experimental diet (PO group) was added perilla oil as a lipid source in the diet of the CO group. The PO group was superior in growth rate and feed efficiency compared with CO group. This trend showed markedly in female of both groups. The fatty acid composition in the muscle of PO group was closely related with those of the diet, while those of CO group were not. For plasma components, total cholesterol (CHOU of PO group was higher than that of CO group. Thiobarbituric acid-reactive substances (TBARS), hydroxyl (OH) radical levels and superoxide dismutase (SOD) activity of plasma were higher in PO group than CO group. The intensity of watermelon-like or cucumber-like aroma was much stronger in PO group with higher level of TBARS and OH radical in plasma compared CO group. Survival rate was also high in PO group with high levels of phagocytic rate, CHOL and SOD activity. These results suggest that perilla oil might be usefulness as a lipid source of the cultured sweet smelt diet, in which result in high quality of the cultured fish.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.689-692
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• 1999

Proximate compositions of muscles and eggs between wild sweet smelt which were caught in Seomjin river and Miryang river, and cultured sweet smelt which were purchased from certain cultured farms in Hadong and Miryang, were compared. Proximate compositions of wild sweet smelt muscles were $76.7\~77.5\%$ for moisture, $18.4\~19.9\%$ for protein, $2.41\~3.47\%$ for lipid, and $1.04\~1.33\%$ for ash content and there were almost no differences between the fishes from Seomjin and Miryang river. Protein and ash content in the cultured fish muscles were similar to those of the wild fish muscles, while the former contained much more lipid and carbohydrate, and less moisture than the latter, especially lipid content differed greatly according to their cultured farms. This might be the result of their different diet compositions. Lipid, protein and carbohydrate content in eggs of the wild and cultured fishes were much higher than those in their muscles. There was a negative correlation between moisture and lipid content in all samples; y= -0.2715x+24.903 (r= -0.7253, p<0.001).

• Fisheries and Aquatic Sciences
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• v.7 no.1
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• pp.1-9
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• 2004

Sweet smelt (Plecoglossus altivelis) were fed four different diets supplemented with either perilla oil $(2.0\%)$ rich in 18:3n-3 (CP), and perilla oil and Enteromorpha compressa meal $(2.0\%)$ (CPA), soybean oil rich in 18:2n-6 (CO), or soybean oil and algal meal (CA) for 4 weeks. The growth performance, fatty acid composition of muscle, plasma lipid peroxidation and blood components of the sweet smelt were then determined. The specific growth rate and feed efficiency in the fish fed the CPA diet were the highest, while the other groups showed similar results. The fatty acid composition of muscle in sweet smelt reflected the dietary lipids; 18:3n-3 was higher in the fish fed the CP and CPA diets, and 18:2n-6 was higher in the fish fed the CO and CA diets. The other fatty acid profiles presented almost no differences with respect to the diet composition. The fish fed the CA, CP and CPA diets contained significantly lower levels of triglyceride, thiobarbituric acid-reactive substances and hydroxyl radical in their plasma than that fed the CO diet. Phagocytic activity was the highest in the fish fed the CPA diet and higher in those of the fish fed the CP and CA diets compared to the CO diet group. The results from this study suggest that a dietary supplement of $2.0\%$ perilla oil together with $2.0\%$ E. compressa meal may improve the growth and health of cultured sweet smelt.

• Fisheries and Aquatic Sciences
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• v.4 no.4
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• pp.171-179
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• 2001

The effect of $\alpha-Tocopherol\;(\alpha-Toc)$ level in diet on the biochemical property of sweet smelt, Plecoglossus altivelis, was investigated. The cultured sweet smelt fish were fed two different diets for 8 weeks; a control diet was added $0.01\%$ of $\alpha-Toc$ (CO group) and an experimental diet was added $1.00\%$ of $\alpha-Toc$ (HT group). Both diets were rich in docosahexaenoic acid (DHA, 22:6n-3) and eicosapentaenoic acid (EPA, 20:5n-3), accounting for $12.3-13.2\%$ and $12.1-12.4\%$, respectively. Growth rate (GR) and feed efficiency (FE) were almost no difference between both groups, but female fish of both groups were superior to male fish in GR and FE. Lipid contents of muscle and ovary were high in CO group compared with HT group, but that of testis showed a similar level in both groups. The proportion of polyunsaturated fatty acids (PUFA) in muscle showed almost no difference in sex and between both groups. In testes, the proportion of PUFA was 1.35 times for HT group to 1.54 times for CO group as much as in ovaries, in which was high approximately 1.5 times compared with muscle. Thiobarbituric acid-reactive substances (TBARS) and hydroxyl (OH) radical levels of plasma were higher in CO group than HT group and superoxide dismutase activity was also slightly high in the former. The intensity of watermelon-like or cucumber -like aroma was related positively with TBARS and OH radical levels in plasma. The level of triglyceride (TG) and total cholesterol (CHOL) in plasma of CO group was higher than those of HT group. Survival rate was high in CO group with higher level of TG and CHOL in plasma.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.10a
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• pp.255-256
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• 2001

Ayu (or called sweet fish or sweet smelt), Plecoglossus altivelis, is a diadromous fish migrated from freshwater to brackish water to spawn, hatched larvae migrated go to seawater and then back to freshwater to grow. In Asia, it has very high consumers demand due to its good taste and Savor. However, population of this species is currently decreasing because of river pollution, over-fishing and dam construction. (omitted)

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.1-29
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• 2024

This article analyzed the infection characteristics of metacercariae of Metagonimus spp. (MsMc) in fish from 9 major water systems in Korea. A total of 19,568 fish in 87 species were examined over a period of 10 years (2011-2020). MsMc were detected in fish from all 44 survey areas in 9 water systems. Most of the surveyed sites showed very low and low infection levels (66.7%), while 33.3% of the areas, such as Tamjin-gang and Seomjin-gang, revealed moderate and high infection levels. High endemicity depends on the abundance of susceptible fish species, especially sweet smelt (Plecoglosus altivelis). The susceptibility index (SI) with MsMc in index fish, Zacco spp., was very low and low levels in 62.0%, moderate in 28.0%, and high in 10.0% regions. The SI was highest in the following order: Yeongam-cheon (283.8), Hoeng-cheon (192.3), Togyo-jeosuji (131.2), Deokcheon-gang (119.1), and Joyang-gang (106.3). The recent infection status of MsMc in P. altivelis was analyzed by the survey localities. In addition, except for P. altivelis, 9 fish species were highly infected with MsMc in some survey areas, including Zacco platypus, Z. koreanus, Z. temminckii, Opsariichthys uncirostris, Rhynchocypris oxycephalus, Carassius auratus, Acheilognathus rhombeus, Onchorhynchus masou, and Tribolodon hakonensis. In Korea, 74 fish species (15 families) are collectively listed as second intermediate hosts of Metagonimus spp. This review provides several novel characteristics of MsMc infection and clarifies the fish species of second intermediate host of Metagonimus spp. in this country.

• Korean Journal of Human Ecology
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• v.15 no.2
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• pp.327-339
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• 2006

We have investigated the distribution of major local foods cultivated in Gwangju City and Jeollanam-Do in order to understand the food culture of Honam region. The local foods were divided into 4 classes: agricultural, aquatic, animal and other products. 124 species of local foods, including 51 agricultural products, 50 aquatic products, 6 animal products and 17 others, were identified from this region. In Jeollanam-Do area, the agricultural products have a variety of fruits and vegetables, and aquatic products have fishes. In particular, rice, cucumber, pear, anchovy, oyster, laver, oyster mushroom, shiitake mushroom, and honey were determined as major local foods in Jeollanam-Do area. Note that Mudeungsan watermelon is cultivated in Gwangju, and sweet smelt and cat fish caught only in Sumjin river and Tamjin river area. In recent years, pumpkin (Cucurbita maxima Duchesne), paprika, kiwi and melon were determined as major local foods in Jeollanam-Do. Furthermore, branding strategy of agricultural and animal products can be said to improve. Wild types of aquatic productions, mushrooms and wild edible greens have been decreasing, whereas cultivated production increasing. The kinds of special local foods in Gwangju City and Jeollanamdo area were influenced by geographical, religious and social factors.