• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.42-42
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• 2003

The far eastern catfish (Silurus asotus) growth hormone (GH) gene was cloned and characterized. The complete nucleotide sequences of genomic GH gene sequences as well as a catfish GH cDNA were obtained by RT-PCR and gene filter screening. The GH cDNA and genomic gene span 1.0 and 1.8 kb from the start codon to the polyadenylation signal, respectively. Both on cDNA and gDNA GH genes, the sequence polymorphism was detected including various silence mutations. The genomic GH gene comprised of only four exons and three introns, which was novel type of fish GH gene structure. The evolutionary relation of the catfish GH gene was inferred based on the comparative phylogenic analysis using the gene structures and sequences.

• 대한수의학회지
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• 제40권3호
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• pp.415-420
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• 2000

Distribution of S-100 protein-immunoreactive cells in the gastrointestinal tract of the catfish, Silurus asotus was investigated by PAP method. S-100 protein-immunoreactive cells were mainly observed just under the epithelium of the gastrointestinal tract. Immunoreactive cells were distributed numerously in the stomach and moderately in the middle part of the intestine, however, a few in the upper and lower part of the intestine.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 1996년도 수산관련공동학술대회발표요지집
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• pp.226.1-227
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• 1996

• 한국수산과학회지
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• 제42권4호
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• pp.349-353
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• 2009

Two feeding trials were conducted to evaluate the soybean meal as a substitute for the fish meal in diet (experiment I), and experimental practical diet and commercial diet (experiment II) for growth of far eastern catfish. In the experiment I, three replicate groups of juveniles (average weight 7.2 g) were fed one of diets containing 0, 10 and 20% soybean meals for 66 days. Survival and final mean weight were not significantly affected by dietary soybean meal levels. No significant differences were observed in feed efficiency, protein efficiency ratio and protein retention of fish fed between 0% (control diet) and 20% soybean meal diets. However, fish fed 10% soybean meal diet showed the lower feed efficiency, protein efficiency ratio and protein retention, and higher daily feed intake compared with fish fed control diet and 20% soybean meal diet. The contents of moisture, crude protein, crude lipid and ash in the whole body were not significantly affected by dietary soybean meal levels. In the experiment II, three replicate groups of juveniles (average weight 7.3 g) were fed either the formulated diet or commercial diet for 66 days. Survival and final mean weight were not significantly different among treatment. Significantly higher feed efficiency, protein efficiency ratio and protein retention, and lower daily feed intake were observed in fish fed experimental practical diet compared with fish fed commercial diet (P<0.05). Proximate compositions of the whole body were not significantly affected by diets. The results of these studies suggest that soybean meal can be used as a substitute for fish meal up to 20% in diet, and the dietary formulation used in the experiment II could be applied to the practical feed for far eastern catfish.

• Fisheries and Aquatic Sciences
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• 제17권4호
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• pp.455-459
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• 2014

A feeding trial was conducted to determine the optimum dietary protein requirement of young far eastern catfish Silurus asotus. Five isocaloric diets were formulated to contain graded levels of protein (35, 40, 45, 50, and 55%). Triplicate groups of fish (initial body weight of 44 g) were hand-fed to apparent satiation for 9-weeks. Weight gain and specific growth rate of fish fed 55% protein diet were significantly higher than those of fish fed 35 and 40% protein diets, but not significantly different from those of fish fed 45 and 50% protein diets. The feed efficiency of fish fed 50 and 55% protein diets was significantly higher than that of fish fed 35, 40 and 45% protein diets. The protein efficiency ratio of fish fed 40% protein diet was significantly higher than that of fish fed 45, 50 and 55% protein diets, but not significantly different from that of fish fed 35% protein diet. The dietary protein level significantly affected whole body lipid and moisture contents. The results of this study suggest that the 45% protein in the diet is optimal for maximum growth of young far eastern catfish weighing in the range of 44 to 227 g.

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.317-325
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• 2020

The Far Eastern catfish (Silurus asotus) is an important commercial freshwater fish in Korea. Investigation of the genetic diversity of wild and cultured domestic catfish groups is essential for the restoration of fishery resources and for increasing local revenue. However, there are relatively few genetic diversity studies on wild and cultured catfish in Korea. In the present study, we analyzed the genetic diversity and association of wild and cultured catfish using five microsatellite markers. We determined that the number of alleles per locus (N_A) ranged from 9 to 25, wherein the Jeonbuk catfish demonstrated the highest mean number of alleles per locus and the cultured catfish exhibited the lowest. The average expected heterozygosity (He) of the wild catfish samples was 0.907, and that of the cultured catfish showed was 0.875. The genetic distances (GD value) among populations of all catfish ranged from 0.138 to 0.242. Jeonnam and Jeonbuk wild catfish were located closest to each other, and the cultured group was separated from the other groups. In conclusion, the present study confirmed that the genetic diversity of wild and cultured catfish was maintained at a high level. In the case of the wild group, it is effective in maintaining diversity due to the continuous fry release by the local fish research institute. However, the genetic diversity of cultured catfish declined. Low diversity is associated with slow growth and weakened immunity, and therefore continuous monitoring is necessary.

• 한국수산과학회지
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• 제52권5호
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• pp.482-495
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• 2019

This study compared the productivity of fish and vegetables grown using the hybrid biofloc technology-aquaponics (HBFT-AP), a semi-recirculating aquaculture system (SRAS), and hydroponics (HP). For the study of fish productivity (HBFT-AP vs. SRAS), fish were provided feed containing 3.0% monobasic potassium phosphate (MKP) for 18 weeks. After the 18-week feeding trial, the average weight of the sampled population (n=100) was not significantly different (P>0.05), while hematocrit (PCV, %), hemoglobin (Hb, g/dL), and plasma K (mEq/L) were significantly different (P<0.05) between the two groups (HBFT-AP: 47.83%, 15.48 g/dL, and 1.39 mEq/L; SRAS 34.83%, 11.81 g/dL, and 2.48 mEq/L). Leaf vegetable productivity (HBFT-AP vs. HP) was compared in three experiments (EXP 1-3), and slower growth was observed in both groups in EXP 2, in which pH was maintained at 5.0 or less throughout the experiment. During the 18-week feeding trial, total ammonia nitrogen (TAN), $NO_3-N$, and $PO_4-P$ levels increased with time in the HBFT-AP system, while the concentration of $NO_2-N$ remained below 0.1 mg/L throughout the study.

• 한국어병학회지
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• 제6권1호
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• pp.1-10
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• 1993

발병한 양식 메기로 부터 vibrio속 균주를 분리하였다. 분리된 균주는 생물학적 생화학적 특성에 기초하여 동정한 결과 V. ordalii로 동정 되었다. 분리균은 glucose, lactose, maltose 와 salicine으로 부터 산을 생산 하였으며, arabinose, galactose, inocitol과 xylose는 이용하지 못하였다. 분리된 V. ordalii를 각각 KL-1, KL-2라 명명하였다. KL-l과 KL-2는 생리학적 특성이 유사하였다. 즉, pH 5-10, NaCl 0%~6.0%에서 발육하였으며, 또한 NaCl 7.0%, pH 10이상 그리고 pH5이하에서는 발육하지 않았다. KL-1 균주를 건강한 메기에 인공 감염시킨 결과 양식장에서 발병된 증상과 동일한 출혈성 궤양이 유발되었다. 감염 24시간 후에 나타난 흙은 반점은 접종 부위 주변에서 부터 확장되기 시작했으며, 감염 120시간 후부터는 배지느러미 부위까지 궤양이 확장되었다. 각각 온도에 따른 실험에서는 $25^{\circ}C$에서 폐사율이 70%로 나타났다. 약제 감수성 시험에서 KL-1 과 KL-2 균주는 모두 GM, K, N, S와 SxT에 감수성을 나타내었으나, CF 및 $L_2$와 VA에는 저항성을 나타내었다.

• 한국수산과학회지
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• 제45권2호
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• pp.139-145
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• 2012

Two feeding trials were conducted to evaluate the effects of experimental extruded pellets (EEPs) and commercial EPs (CEPs) on Far Eastern catfish $Silurus$ $asotus$ in pilot- (experiment I) and commercial-scale (experiment II) tanks. Four diets were prepared: three EEPs (EEP1, EEP2 and EEP3) that contained different amounts of tuna fish meal, soybean meal, and squid liver oil, and one CEP diet. In experiment I, three replicate groups of juveniles were fed one of the four EPs in pilot-scale tanks for 19 weeks. The weight gains (WGs) of fish fed EEP1 and CEP were significantly higher than those of fish fed EEP2 or EEP3. The highest feed efficiency (FE) was observed in fish fed the CEP diet ($P$<0.05), and the FE of fish fed EEP1 and EEP3 were significantly higher than that with EEP2 ($P$<0.05). In experiment II, juveniles were fed one of four EPs in commercial-scale tanks for 19 weeks. WG and FE values of fish fed EEP1 and CEP were higher than those of fish fed EEP2 and EEP3. The results of this study indicate that the dietary formulation used in EEP1 could be used as a practical feed for Far Eastern catfish.

• 한국수산과학회지
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• 제32권1호
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• pp.56-61
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• 1999

참메기, Silurus asotus를 대상으로 수온 ($15^{\circ}C,\;20^{\circ}C,\;25^{\circ}C$ 및 $30^{\circ}C$)과 광주기 (24L:0D, 12L:12D 및 0L:24D)에 따른 산소 소비량의 변화를 연속적인 컴퓨터 모니터링 시스템을 이용하여 조사하였다. 평균 무게 280g의 참메기의 산소 소비량은 수온의 증가에 따라 증가하였고, $15^{\circ}C$에서 $35.2\~96.4mg\;O_2/kg$ fish/hr, $20^{\circ}C$에서$78.6\~127.9mg\;O_2/kg$ fish/hr, $25^{\circ}C$에서$120.1\~231.7mg\;O_2/kg$ fish/hr, $30^{\circ}C$에서 $197.5\~352.3mg\;O_2/kg$ fish/hr으로 나타났다(p<0.05). 광주기에 따른 산소 소비량은 암기 조건에서 보다 명기 조건에서 산소소비량이 더 높게 나타났다. 또한, 24L:0D와 12L:12D와 비교하여 0L:24D에서 평균 산소 소비량이 낮게 나타났다(p<0.05). 산소 소비량의 최대값과 최소값의 차이는 수온이 상승함에 따라 증가하였고, 12L:12D에서 가장 큰 것으로 나타났고, 새벽녁과 저녁 무렵에 산소 소비량의 급격한 변화를 나타내었다. 특히, 12L:12D의 조건에 두었을 때 명기와 암기에 대한 뚜렷한 반응을 보였다.