• 한국양식학회지
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• 제13권4호
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• pp.359-362
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• 2000

Mitotic gynogenesis was induced in the far eastern catfish, Silurus asotus using UV-irradiated heterospecific sperm and cold shock treatment. Eggs were activated with the sperm of mud loach, Misgurnus mizolepis which has been irradiated with UV at dose of 9,000 ergs/$mm^2$. To determine the optimum duration required to prevent the first cleavage, a cold shock at 4$^{\circ}C$ with duration of 20, 30 or 40 min was applied to the eggs 50 min after activation. To induce diploidization of mitogenesis, the most effective protocol was to apply cold shock to 50-min old (after activation) eggs at 4$^{\Circ}C$ for 30min.

• 한국양식학회지
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• 제15권4호
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• pp.275-277
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• 2002

양식 산업성이 큰 메기 S. asotus를 대상으로 한 염색체 공학의 기초 자료를 얻기 위하여 본 연구를 수행하였다. 본 종의 난발생 중 핵분열(karyokinesis)을 조직학적으로 조사한 결과, 수온 24${\pm}$0.5$^{\circ}C$ 조건에서 핵분열은 수정 후 31분에 가장 현저하였으며, 이 시기는 메기에서의 제 1 난할 중기에 해당하였다.

• 한국양식학회지
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• 제10권1호
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• pp.63-68
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• 1997

메기의 산란행동을 관찰하기 위하여 1994년 5월부터 1995년 7월까지 산란시기에 HCG, 초어의 뇌하수체 등의 호르몬을 주사하여 이들의 행동을 관찰하였다. 이들의 산란행동은 기본적으로 chasing-clinging-embracing (enfolding) 순으로 이루어 졌는데, 주사후 15-16시간이 경과하면 산란행동을 시작하였고, 2-3시간 동안 산란행동을 하다가 19시간이 지나면 모든 행동이 끝났다. 그러나 지금까지 알려진 일본에서 메기의 자연산란 행동과는 수컷이 접근하는 방법과 수컷이 암컷을 감싸 조일 때 수컷의 뒷지느러미의 방향이 달랐다. 그리고 한국산 메기는 수컷이 암컷에 접근할 때 등쪽에서 접근하여, 배쪽에서 접근하는 S. biwaensis 와도 차이를 보였다.

• 환경생물
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• 제33권4호
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• pp.476-483
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• 2015

We are aim to evaluate lysozyme and antibacterial activity of cultured catfish, Silurus asotus, that fed supplementally with Galla rhois extracts for eight weeks. Lysozyme activity in the spleen and serum of administrated group was higher than not administrated group, but in mucus of the lysozyme activity was no regular than other organ. The lysozyme activity of the spleen, kidney, serum of administrated fishes were increased after 2 weeks and that was highest after 8 weeks. Ht and GLU in serum of administrated fishes were gradually increased but GOT was decreased after 8 weeks. There is no significant differences in HB (Hemoglobin) and TP (Total Protein) each groups. Furthermore, there is no pathohistological changes of kidney and liver of tested fishes. The cumulative survival rates of administrated group after intraperitoneal injection of Aeromonas veronii with $6.5{\times}10^6cfu\;mL^{-1}$ was presented 33% in 9 days. As the Results, Galla rhois extracts has any beneficial effects for immunity elevation and antibacterial activity in catfish, Silurus asotus.

• 한국어병학회지
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• 제22권2호
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• pp.107-113
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• 2009

지중 양식 중인 메기, Silurus asotus에 Ameiurus nrbulosus 상피종과 유사한 질병이 발생하였다. 상피종은 피부, 지느러미 및 수염에 독립된 형태로 대형의 종괴를 형성하고 있었으며, 조직학적으로는 증생된 상피를 관입된 결합조직에 의해 피포되어 구획되어져 있으며, 증생된 상피 세포는 불규칙한 배열을 하고 있었다. 또한 종양의 내부에는 점액세포와 곤봉세포가 다수 내재되어 있었다. 본 상피종의 발생 원인은 단정할 수는 없지만 상피종을 유발하는 것으로 알려진 바이러스는 검출되지 않았기 때문에 기존에 어류의 종양원으로 보고된 바이러스이외의 종류이던가 아니면 다른 요인이 작용할 것으로 생각되지만 본 연구에서는 원인을 추정할 수 없었다.

• 한국발생생물학회지:발생과생식
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• 제19권3호
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• pp.153-161
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• 2015

For the 2 years of farming, at the indoor circulating aquaculture system, four kinds of skeletal deformities were found among 60 Far Eastern catfish, Silurus asotus. Deformities saw jawbone's luxation, abnormality of upper lip and malocclusion. Spinal deformity was most fatal deformities with low weight and small length. Jawbone's luxation had 1 maxilla and 2 mandibles. Abnormality of upper lip had just lip was back over. Malocclusion's left maxilla and right maxilla were not balanced. This experiment was any deformities in this species through the deformity can grasp how it affects.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.228-229
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• 2000

Trypanosoma sp. (Sarcomastigophora: Kinetoplastida) was found in the blood of the Korean catfish, Silurus asotus, for the first time in Korea. The morphological characteristics of Trypanosoma sp. in the present study were similar with those of T. carassii, T. tincae and T. danilewskyi. However, the free flagellum length of Trypanosoma sp. was obviously shorter than that of those species. The species identification was reserved until elucidating the pleomor-phism according to the phase of infection and the cross infectivity among fish species.

• 한국발생생물학회지:발생과생식
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• 제22권4호
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• pp.319-329
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• 2018

The experiment was conducted for 210 days to determine the effect of feeding, and starvation, and exposure to sodium nitrite ($NaNO_2$) on the survival, physiological changes, hematological parameter, and stress response of Far Eastern catfish, Silurus asotus. The survival of the starved group was lower than that of the fed group during the experiment. Starvation resulted in retardation of growth, which provides an example of fish that failed to continue to grow and remain in a good condition. Blood analyses (cortisol and glucose) showed significant differences of stress response between the fed and starved groups exposed to $NaNO_2$ at the conclusion of the experiment (p<0.05). These results suggest that all nutritional parameters used for starvation and feeding with $NaNO_2$ stress in this experiment appear to be a useful index of nutritional status in Far Eastern catfish.

• 한국어류학회지
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• 제13권1호
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• pp.85-88
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• 2001

메기 Silurus asotus에서 염색체조작을 효과적으로 하기 위하여, 여러 온도 조건에서의 난할율과 제2, 제3 난할 시간의 평균화에 의한 체세포분열 간격지수 (${\tau}_o$)를 조사하였다. 빠른 난 발생과 비동시적 발생은 고온에서 더욱 뚜렷하게 나타났다. 메기의 체세포분열 간격지수는 $22^{\circ}C$에서 $21.5{\pm}1.4$분, $24^{\circ}C$에서 $18.5{\pm}1.2$분 그리고 $26^{\circ}C$에서 $14.0{\pm}2.1$분이었다. 3가지 수온조건과 ${\tau}_o$ 간에는 Y=-1.85X+21.9 ($R^2=0.9868$, Y는 ${\tau}_o$ 그리고 X는 수온)의 직선회귀가 성립되었다.

• Fisheries and Aquatic Sciences
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• 제26권11호
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• pp.660-668
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• 2023

This study aimed to investigate the growth performance of far eastern catfish (Silurus asotus) on outdoor fish farms to obtain basic data for the domestic eastern catfish aquaculture industry. An outdoor fish farm was directly monitored from June 2018 to October 2019 to determine the farming conditions, growth performance, and water quality. The growth performance in 2017 was analyzed using data from the same fish farm. Three years of monitoring showed that the fish farm required approximately 5-6 months between stocking, harvesting, and selling an S. asotus batch. The growth parameters, namely, the weight gain rate (WGR), specific growth rate (SGR) for culture periods, SGR for feeding periods, and feed coefficient rate (FCR), were 4,664.7%, 1.27%, 2.43%, and 1.25 in 2017; 6,452.0%, 1.52%, 2.79%, and 1.42 in 2018; and 3,270.0%, 1.11%, 2.12%, and 1.38 in 2019, respectively. Moreover, the WGR was two-fold higher in 2018 than 2019, whereas the FCR was more effective in 2019 than 2018, presumably because of the stocking density. No mass mortality was observed during the water quality analysis. The results of this study provide basic data for the development of the catfish industry.