• Korean Aquaculture
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• v.19 no.1
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• pp.43-51
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• 2007

말라카이트그린(MG) 및 L-말라카이트그린(LMG)의 소멸은 뱀장어 Anguilla anguilla 유생에서 100일정도 걸린다. 실뱀장어(평균체중: 4.1 g)가 $23.0-26.5^{\circ}C$의 다양한 수온범위에 24시간동안 아주 낮은 농도(0.1 mg/l MG)에 약욕을 실시하였다. 처리한 후 실뱀장어는 말라카이트그린이 없는 깨끗한 물이 들어 있는 수조로 옮겼다. 뱀장어가 수용된 수조에는 순환여과 된 사육수를 공급하였다. 일정한 시간 간격으로 수집된 10마리의 뱀장어 및 사육수의 샘플은 high-performance liquid chromatography (HPLC)으로 분석하였다. 말라카이트그린의 가장 높은 농도는 $435{\pm}59\;{\mu}g/kg(mean{\pm}S.D.)$로서 처리시작 후 6시간에서 나타났다. L-말라카이트그린(LMG) 대사물의 농도는 비교적 높게 나타났으며 ($>100\;{\mu}g/kg$), 처리시작 후 6시간 및 처리종료 후 1500시 사이에서 안정적으로 나타났고 최대농도는 $831{\pm}231\;{\mu}g/kg$이었다. 비록 뱀장어는 체중이 증가하지는 않았지만 노출 후 24시간 후에도 L-말라카이트그린(LMG)은 여전히 전어체 kg당 $15{\pm}12\;{\mu}g/kg$ 함량이 존재하였다. 말라카이트 그린은 처리 이후 1920 및 2400시에서는 발견되지 않았다. 생물적 여과사육수와 순환여과시스템에서는 말라카이트그린이 발견되지 않았다. 본 연구에서는 부가적으로 빠르게 성장하여 11개월 된 뱀장어 두 마리를 샘플하여 분석에 사용하였다. 두 마리의 뱀장어는 실뱀장어기(0.3g)일 때 $0.15\;mg\;l^{-1}$ 농도의 말라카이트그린이 처리되었었다. 뱀장어의 근육조직에서는 지질 크로마토그래피-질량 분광광도계분석에 의해 말라카이트그린과 L-말라카이트그린이 측정 가능한 양으로 함유되지 않음을 확인할 수 있었다($<\;0.2\;{\mu}g\;kg^{-1}$).

• Korean Journal of Ichthyology
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• v.29 no.2
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• pp.94-100
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• 2017

Three pseudo-silver eels (PS1~PS3) were found by analysis of silvering index and biological characteristics of 454 eels, Anguilla japonica, collected from the 9 sites of Korean fresh and brackish waters from September 2014 to August 2015. Two specimens (PS1~PS2) from Lake Soyang and one (PS3) from Geum river estuary were identified as pseudo-silver eel showing a large difference between silvering index and GSI. The external morphology of the pseudo-silver eels were in S2 (late silver eel) stage, but they were classified into Y1 (yellow eel) and Y2 (late yellow eel) stage in GSI, Gut index, Eye index and Y2 stage in gonadal development and mean egg diameter.

• Journal of environmental and Sanitary engineering
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• v.4 no.1 s.6
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• pp.53-60
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• 1989

This study was performed to investigate the contents of heavy metals in Anguilla japonica habiting in Korea. The samples were collected along by Nak Tongriver, Young San river and culture farms. Lead, Cadmium, Copper, Zinc, Manganese, Chromium were tested by the Atomic Absoption Spectrop-hotometer after wet digestion, Mercury was tested by using mercury analyzer. The results were as follows: 1. Aresenic, Copper contents in the four parts were the higest values in liver 2. In total mercury contents of the each parts, the higest value was detected in muscle. 3. In all metals, Zinc and Manganese were detected with high contents, Mecury and Cadmium were detected with low contents. Lead, Cadmium, Zinc, chromiumi, Manganese were detected with high in bone. 4, The difference was not significant between natural and feeding Anguilla Japonica, but significant correlation with parts.

• 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.27 no.4
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• pp.1109-1117
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• 2015

Recently, import supply of glass eels from Philippines has been increased in South Korea, and the species distinction was very important to import traders and Anguilla marmorata and A. bicolor pacifica are major species at Philippines. In this study, the species distinction and the rate were researched targeting imported glass eels from the estuaries of North Luzon and the South Mindanao in May and July, 2014. Dorsal fin position and pigmentation pattern at caudal fin are the trait standard for species distinction. The results about morphological identification were coincide with the result of the genetic identification, and the regional distribution of A. marmorata rate was over 90% at North Ruzon in May. However, the rates of A. bicolor pacifica and A. mamorata were 63.3% and 36.7% in May, and were 53.3% and 46.7% in July respectively at South Mindanao.

• Korean Journal of Ecology and Environment
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• v.47 no.spc
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• pp.31-38
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• 2014

The fish community and upstream of glass eels (Anguilla japonica) in the Imjin River estuary Gyeonggi-do, Korea was investigated from 2008 to 2012. During the surveyed period 43 species belonging to 18 families were collected. Korean endemic species was Microphysogobio jeoni which showed a ration of 0.04% in collected species. Exotic fishes were Carassius cuvieri and Ctenophayngodon idellus, and comprised 0.06% of the total individual number. Among the fish species observed, 17 species of the freshwater fish (40.5%), 6 species of migration fish (14.2%), 8 species of the brackish water fish (19.1%) and 11 species of sea water fish (26.1%). In terms of composition ration, Anguilla japonica (glass eels, 49.8%), Coilia ectens (23.3%), Saurogobio dabryi (8.1%), Repomucenus olidus (3.3%), Lateolabrax maculata (2.9%) and Chelon haematocheilus (2.8%) were found to display high individual number. On the other hand, C. ectens (33.6%), C. haematocheilus (14.2%), Cyprinus carpio (10.5%), Mugil cephalus (9.1%) and S. dabryi (7.6%) were dominated of biomass. The dominant species of individual was A. japonica (glass eels), and subdomint species included C. ectens. The fish biomass catched of fisherman in the Imjin River (Paju-si) were 83.6~240.3 t by each year. The year 2011 and 2012 were decreased rapidly. Among these, M. cephalus (48.0~80.0%), C. carpio (6.7%), Carassius auratus (4.9%), Silurus asotus (3.9%), Takifugu obscurus (2.5%), Anguilla japonica (adult, 2.2%) and Pseudobagrus fulvidraco (2.1%) dominated of biomass. Body weight of glass eels at each year were 0.03~ 1.13 t, average 212.0 kg and 1,325,000 individual by 0.16 g each one individual.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.469-469
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• 2000

뱀장어 Anguilla japonica는 민물에서 자라고 알을 낳을 때가되면 바다로 회유한다. 그러나, 해양에서 성숙된 뱀장어나 알이 채집되지 않아 정확한 산란기는 알려져 있지 않았다. 어류의 이석에는 하루주기로 나이테(일륜)가 형성되기 때문에 이 일륜의 수로부터 산란기를 추정할 수 있다. 지금까지 실뱀장어 이석의 미세성장선수로부터 산란기를 추정한 자료의 문제점을 분석하고, 산란장 주변에서 채집된 댓잎뱀장어(leptocephalus) 이석의 미세성장선수로부터 산란기를 추정하였다. (중략)

• Journal of fish pathology
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• v.20 no.3
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• pp.291-297
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• 2007

The effect of aspirin on the recovery of nitrite-induced methemoglobinemia in cultured eels (Anguilla japonica) was studied. Methemoglobinemia was induced by exposing eels to nitrite (120 ㎎ NO2-N/ℓ) for 24 hr. The nitrite exposed eels were bathed in 20 ppm aspirin solution (Aspirin), 0.8 % NaCl solution (NaCl), 20 ppm aspirin plus 0.8% NaCl solution (NaCl + Aspirin) and 50% nitrite free water(control) for 24 hr to recover from nitrite toxicity. Peripheral blood was taken from the arterious bulb from all groups to analyse hematocrit value, hemoglobin concentration, and nitrite concentration of the blood. Histopathological features of gill were also observed. Aspirin and control groups were more effective than NaCl and NaCl + Aspirin groups in recovery of hematocrit value and hemoglobin concentration, methemoglobin rate and nitrite concentration. The histopathological features on the gill of aspirin group were similar to those of normal eels, but other groups showed focal hyperemia in the lamellar carpillaries, epithelial hyperplasia. These results suggested that aspirin was very effective to recover from methemoglobinemia in nitrite-induced cultured eels.

• Korean Journal of Microbiology
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• v.22 no.1
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• pp.41-48
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• 1984

Twenty two cultures of pathogenic bacteria were isolated from cultured eels(Anguilla japonica) from Asan Hatchery. The bateria were characterized by their biochemical properties, serological relationships, infectivity to gold fish and susceptibility to various antimicrobial compounds. Fourteen of 22(64%) cultures were identified as Edwardsiella tarda, five (23%) as Aeromonas hydrophila and three (14%) as Vibro anguillarum. Edwardisiella tardo isolates proved to be the main cause of the disease in cultured eels. They were serologically homogeneous and their virulency to gold fish was higher than any of the other groups of bacteria tested. The virulence of 3 isolates were low in gold fish exposed to the bacteria by the waterborn route. Ten strains were tested for their susceptibility to 12 antimicrobial compounds and were resistant to from one to six drugs: in particular, tetracycline derivatives and sulfisoxazole.

• Journal of fish pathology
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• v.20 no.2
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• pp.161-167
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• 2007

Acute toxicity of formalin (37% formaldehyde) was conducted to determine the median lethal concentration (LC50) on eel (avarage weight 96 ± 3.6 g, average total length 43 cm), Anguilla japonica at concentrations ranging from 0 to 500 ppm. In particular, this study was designed to estimate the safety concentrations of formalin in testing eels to eradicate Pseudodactylogyrus. All fish died after 10 hours and 24 hours at 500 ppm and 400 ppm, respectively. After 24 hours, cumulative mortality was 96.6% and 13.3% at 300 ppm and 200 ppm formalin, respectively. However, all experimental fish were alive after 24 hours at 100 ppm. The lethal concentration values were computed by using non-linear least square method. At the start of the test, water temperature, pH and dissolved oxygen level were 27～28℃, 7.4 and 5.55 ppm, respectively. The 24 hr-LC50 were 269 ppm.