• IMMUNE NETWORK
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• v.8 no.4
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• pp.124-129
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• 2008

Background: The immunomodulatory effects of Korean mistletoe (Viscum album Coloratum) on the innate immune responses of eel (Anguilla japonica) were studied. Methods: Mistletoe, Freund’s complete adjuvant (FCA), or phosphate-buffered saline (PBS) as a control was injected into eel peritoneal cavities. Results: Nitroblue tetrazolium (NBT)-positive cells in the head kidney of eel were significantly augmented by the second day post-injection of mistletoe. Reactive oxygen intermediates (ROI) were more produced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity in the serum of fish 2 days after injection with mistletoe was also significantly higher than that in the serum of the control fish. The optimal concentration of mistletoe in inducing the highest serum lysozyme activity was revealed to 500${\mu}$g/200 g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. Conclusion: Korean mistletoe appeared to be a good activator of the non-specific immune responses of eel.

• Journal of fish pathology
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• v.18 no.1
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• pp.59-66
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• 2005

In the present paper, the immunostimulatory effects of Korean mistletoe (Viscum album Coloratum) on the non-specific immune responses of Japanese eel (Anguilla japonica) were examined. Eel were innoculated with mistletoe, Freund's complete adjuvant (FCA), or phosphate-buffered saline (PBS) as a control into their peritoneal cavities. The number of nitrobule tetrazolium (NBT)-positive cells in the head kidney of fish was significantly increased by the second day post-injection of mistletoe. ROI products were more enhanced in mistletoe-injected fish kidney leucocytes than in FCA-injected ones. The level of lysozyme activity detected in the serum of fish 2 days after injection with mistletoe was also significantly higher than that found in the serum of the control fish. The appropriate concentration of mistletoe to induce the highest level of serum lysozyme activity was revealed to 1000${\mu}g$/200 g of fish. In phagocytic activity assay, mistletoe-sensitized eel kidney phagocytes captured more zymosan than did the control fish. Korean mistletoe appeared to be a good activator of the non-specific immune responses of Japanese eel.

• Journal of fish pathology
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• v.2 no.2
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• pp.83-90
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• 1989

Edwardsiella tarda, the causative organism of Edwardsiellosis, was isolated from the water and the eel, Anguilla japonica of the recirculating eel culture ponds in 1988. E. tarda was always isolated from the water of eel culture ponds in the number of log 2.30~log 4.78 CFU/$m{\ell}$ without distinguishable seasonal characteristics. The counts of isolated E. tarda were changed with the health condition of the eel, i. e., a number of E. tarda were isolated from all checked organs, intestine contents, liver, spleen and kidney of the diseased eel, however, it was hardly isolated from spleen and kidney of the healthy eel. The isolates were classified according to o-agglutinating test into three serotypes (I, II, III). There were no distinct differences in the composition of the serotypes between intestine contents of eel and pond water samples(I, 52.4~53.3% ; II, 20.0~23.8% ; III, 4.8~6.7%). Serotype I was ascendant in the spleen(66.7%) and the kidney(73.7%) samples. By experimental challenge, most of serotype I proved highly virulent to eel in comparison with the other serotypes tested.

• Journal of fish pathology
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• v.36 no.2
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• pp.287-292
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• 2023

This study investigated the genetic determinants of plasmid-mediated antibiotic resistance (PMAR) to quinolones and tetracycline in 106 Aeromonas strains isolated from eel (Anguilla japonica, 70 strains) and ornamental fish (36 strains) in Korea. Quinolones and tetracycline resistance phenotypes were found to be widely distributed throughout the both fish groups. However, the prevalence of qnr and tet genes was higher in ornamental fish strains than in eel strains (42.9% vs. 86.1% for qnr and 51.4% vs. 69.4% for tet). In addition, the profiling of the present genetic determinants revealed the dominance of qnrS, tetA, tetE and tetE+qnrS genes for eel strains but of tetA+qnrS qnrS and tetE+qnrS genes for ornamental fish strains. These results indicate that aquaculture and related industries could be a major threat to public health due to the possible spread of PMAR.

• Journal of Korean Society on Water Environment
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• v.29 no.5
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• pp.656-665
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• 2013

This research was conducted to investigate pollutant load unit factor from aquacultural farms. Pollutant load unit factors were investigated on the 13 kinds of fish type, i.e., Trout, Leather Carp, Eel, Carp, Cartfish, Freshwater Eel, Crucian Carp, Colored Carp, Sturgeon, Marsh Snail, Sweetfish, Pond Snail, Eriocheir Sinensis. Water qualities in aquacultural farms were investigated wide range of values by fish type and pollutant items. High BOD and COD values were observed at the Leather Carp (Ponded water system), Cartfish (Ponded water system) and Freshwater Eel (Recirculating System). TOC and DOC values were relatively high at the Freshwater Eel (Recirculating System) and Eriocheir Sinensis (Extensive). Eel (Ponded water system) and Freshwater Eel (Recirculating System) produced high concentrated nutrient pollutants, i.e., T-N, T-P. Pollutant load unit factors are dependent on fish type, aquacultural type, water quality items, etc. If some fishes have similar basic unit values, those could be applied for TMDLs as a group of fish having same pollutant load unit. The water quality concentrations of post treatment facilities' (mainly reservoir tank) effluent were higher than those of fish raising bath because of extracting pollutant from sediment in the reservoir tank. Therefore, it needs to the management and regulations about post treatment facilities.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.365-369
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• 1999

A study on quinolone antibacterial, norfloxacin, was performed to apply for the control of bacterial diseases in eel (Anguilla japonica). Norfloxacin was proved excellent in antibacterial activity and sensitivity against fish bacterial pathogens when compared with the existing antibacterials and antibiotics. And any side effect was not observed during the period of indicated use. An outline of minimal inhibitory concentration was $0.03{\sim}0.1{\mu}g/ml$, $TLm_{48h}$ value was 3,500mg/l. The residual time of the day in fish body was less than 17 days and any pathological changes were not observed. The study has revealed that norfloxacin can be applied to treat some fish bacterial disease by the dosage of 100g/day/ton of fish body weight for about 3 days perorally. Further, norfloxacin may be used for the control of bacterial pathogens in eel.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.6
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• pp.1209-1216
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• 2014

This feeding experiment was conducted to investigate the effects of slurry type diet on growth performance and survival rate of growing leptocephalus, eel larva. We need to find new materials of diets for rearing eel larvae. Test diets were formulated with the eggs of the shark, fish soluble concentrate, soybean peptide and fish protein hydrolysate. Fish (average length 6 mm) were fed 3 slurry type diet(A, B and C) based on shark egg for 5 times per day. During feeding experiment, survival rates were significantly different among 3 slurry type diets. Total protein, lipid, moisture, ash and free amino acids contents were analyzed for slurry type diets. Leptocephalus fed the C slurry type diet was grown up to $38.0{\pm}9mm$ at 150 days. But all leptocephalus fed B slurry type diet were died at 100 days, reaching $16.4{\pm}8mm$. This results suggest that basic information for diet development of eel leptocephalus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.860-868
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• 2014

The study was performed to investigate changes in hematological responses and antioxidative enzyme activities (superoxide dismutase, SOD; catalase, CAT) of Japanese eel Anguilla japonica following exposure to 0 (control), 2.33, 4.60, 6,64 and 8.78 mM nitrite-N in fresh water for 48 h. Hematological parameters such as plasma nitrite, electrolytes, cortisol, glucose, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), hemoglobin (Hb), methemoglobin (metHb) and NADH-methemoglobin reductase (NMR) were measured. Plasma nitrite, cortisol, metHb and NMR increased directly with increasing ambient nitrite concentration, while Hb content showed a progressive decline. Levels of plasma potassium, GOT and GPT of the eel exposed to 6.64 mM ambient nitrite were significantly higher than the control fish. The activity of SOD and CAT in plasma, gill and liver of the eel following exposure to nitrite were augmented by increasing ambient nitrite. Levels of plasma nitrite, metHb, NMR, cortisol, glucose and antioxidative enzyme activities of the eel exposed to 2.33 mM ambient nitrite were significantly higher than the control fish. This study suggested that the eel acutely exposed to elevated ambient nitrite causes nitrite-induced stress responses, changes in antioxidative enzyme activities and hematological parameters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.139-148
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• 1985

Changes in fish jelly forming ability of pretreated and frozen common carp and conger eel were examined. Four kinds of pretreated samples were prepared such as round, mechanically separated meat using fishmeat separator, chopped and water washed meat and fish meat paste. The quality of pretreated samples and fish jelly products made from pretreated sample were generally in good condition for three months of frozen storage at $-30^{\circ}C$. Judging from fish jelly forming ability, the round state of common carp was superior to other pretreated samples during frozen storage. In case of conger eel, fish meat paste revealed totter jelly forming ability than any other pretreated samples during frozen storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.678-684
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• 2001

In Korea, the conger eel, Conger myriaster and sea eel, Muraenesox cinereus have been eaten as a sliced raw ash meat for a long time. This study was carried out to compare the food component and sensory differences of the conger eel and sea eel as a sliced raw fish meat. The yield and ash content of conger eel were slightly higher than those of sea eel, and no significant differences in moisture, crude protein and crude lipid. The major fatty acids of conger eel were 16:0 ($19.9\%$), 18 : 1n-9 ($36.1\%$) and 22: 6n-3 ($8.3\%$), while those of sea eel were 16:0 ($24.0\%$), 16: 1n-7 ($12.1\%$) and 18:1n-9 ($21.9\%$), The contents of (n-3)-fatty acids were low in all of the two samples. The contents of total amino acid in the conger eel and sea eel were 19,147.2 mg/100 g and 18,527.1 mg/100 g, respectively. The major amino acids of two samples were aspartic acid, glutamic acid and lysine. The chemical score in protein of conger eel was higher about $6\%$ than that of sea eel, and the Ca and P contents of conger eel were also higher than those of sea eel. Although the nutritional value of conger eel as a sliced raw fish meat was generally higher than that of sea eel, the sensory scores in taste and texture of conger eel were lower than those of sea eel.