• Environmental Analysis Health and Toxicology
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• 제30권
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• pp.6.1-6.7
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• 2015

Objectives This study aimed to estimate the effects of 4-nonylphenol (NP), a ubiquitously present surfactant in aquatic environments, on the anti-oxidant systems of the liver in the Far Eastern catfish Silurus asotus. Methods Changes in biochemical parameters involved in glutathione (GSH)-related and other anti-oxidant systems were analyzed following 4 weeks of 4-NP administration (0.1 and 1.0 mg/kg diet) via a formulated diet to catfish. Results 4-NP exposure induced an elevation in hepatic lipid peroxide levels and an accompanying decrease in reduced state GSH after 2 weeks, suggesting pro-oxidant effects of the chemical in catfish. This oxidative stress was associated with an inhibition of the GSH-utilizing enzyme glutathione peroxidase at the same time point. This inhibition was restored after 4 weeks. The activities of other anti-oxidant enzymes, i.e., glutathione reductase, superoxide dismutase and catalase were increased after 4 weeks. These enzyme increases occurred more strongly at the higher 4-NP concentration (1.0 mg/kg diet). Conclusions 4-NP given to catfish at 0.1 to 1.0 mg/kg diet, concentrations relevant to environmental levels, depletes the endogenous anti-oxidant molecule GSH and temporarily inhibits GSH-related anti-oxidant enzymes. Such declines in anti-oxidant capacity and elevated oxidative stress seem to be compensated eventually by subsequent activation of various anti-oxidant enzyme systems.

• 한국식품영양학회지
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• 제17권2호
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• pp.156-162
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• 2004

미이용자원인 어류 carotenoid에 관한 비교 생화학적 연구의 일환으로서, 메기과의 자연산 및 양식산 메기와 한국 특산의 담수어류인 미유기의 표피 carotenoid를 TLC, column chromatography 및 HPLC로 분리하고 NaBH$_4$에 의한 환원반응, I$_2$에 의한 이성화반응 및 UV-visible spectrophotometer로 비교하고 IR 및 Mass spectrum을 측정하여 carotenoid를 동정한 결과는 다음과 같다. 자연산 메기 표피의 총 carotenoid 함량은 0.27 mg($\pm$0.7)%였으며 carotenoid의 조성은 zeaxanthin 25.8%, diatoxanin 9.7% 및 cynthiaxanthin 9.1%로서 주성분을 이루고 있었으며 그 외 isocryptoxanthin 6.5%, $\beta$-carotene 5.1%, $\beta$-cryptoxanthin 4.3%, lutein 3.4% 및 $\alpha$-cryptoxantin 2.4%의 순으로 함유하고 있었다. 양식산 메기 표피의 총 carotenoid 함량은 0.07 mg($\pm$0.03)%로서 자연산 메기에 비해 다소 낮았으며, carotenoid의 조성은 lutein 48.5%, zeaxanin 13.9% 및 isocryptoxanin 13.3%로서 주성분을 이루고, 그 외 $\beta$-carotene 9.5%, $\beta$-cryptoxantin 1.4% 및 $\alpha$-cryptoxanthin 4.6%의 순으로 함유하고 있었다. 한편 미유기 표피의 총 carotenoid 함량은 0.75 mg($\pm$0.25)%로서 메기과의 다른 어종에 비해 함량이 높았으며, carotenoid 조성은 zeaxanthin 24.5%, 7'8'-dihydro-$\beta$ -carotene-4-ol 24.1%, 7'8'-dihydro-$\beta$-carotene 17.9% 및 7'8'-dihydro-$\beta$-carotene-3-ol 10.8%로서 주성분을 이루고 있었으며 그 외 diatoxanthin 8.7%, cynthiaxanthin 6,7% 및 lutein 5.0%의 순으로 함유하고 있었다. 이러한 결과는 parasiloxanthin과 7',8'-dihyo-parasiloxanthin을 주성분으로 함유하는 biwa호수 메기, P. asotus 표피 carotenoid 조성과 비교하여, 미유기에서는 7'8'-dihydro-$\beta$-carotene의 구조를 가진 carotenoid가 존재하였으나 자연산 및 양식산 메기에서는 발견되지 않아 특이하였다.

• 한국어류학회지
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• 제18권3호
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• pp.209-215
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• 2006

한국의 퉁가리과 어류 3종의 형태학적 특성을 classical dimension과 truss dimension을 사용하여 파악하였다. Arc sin square root 전환 후, 18가지의 계측형질을 체장에 대한 비율로, 그리고 3가지의 계측형질은 두장에 대한 비율로 각각 분석하였다. 퉁사리, Liobagrus obesus는 classical dimension과 truss dimension의 4가지 계측 형질이 퉁가리, L. andersoni와 자가사리, L. mediadiposalisa에 비하여 컸다 (P<0.05). 퉁사리와 퉁가리는 truss dimension의 3가지 계측형질이 자가사리보다 컸다 (P<0.05). 조사된 퉁가리과 어류의 6가지 계측형질에서는 유의적인 차이가 없었다. 본 연구에 사용된 dimension들은 한국산 퉁가리과 어류들을 구별할 수 있는 적절한 분류학적 지표로 사용될 수 있으리라 사료된다.

• The Korean Journal of Physiology
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• 제27권2호
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• pp.163-174
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• 1993

Vertebrate retinal neurons, like brain tracts farm complex synaptic relations in the enter and inner plexiform layers which ape equivalent to the central nervous system nuclei. The effects of $\gamma-aminobutyric$ acid(GABA) and glycine on retinal neurons were explored to discern the mechanisms of action of neurotransmitters. Experiments were performed in the superfused retina-eyecup preparation of the channel catfish, Ictalurus punctatus, using intracellular electrophysiological techniques. The roles of GABA and glycine as inhibitory neurotransmitters are well established in the vertebrate retina. But, we found that the depolarizing action of GABA and glycine on third-order neurons in the catfish retina. GABA and glycine appeared to act on retinal ueurons based on the observations that (1) effects on photoreceptors were not observed, (2) horizontal cells were either hyperpolarized $({\sim}33%)$ or depolarized $({\sim}67%)$, (3) bipolar cells were all hyperpolarized (4) amacrine and ganglion cells were either hyperpolarized $({\sim}37%)$ or depolarized $({\sim}63%)$, (5) GABA and glycine may be working to suppress presynaptic inhibition. The results suggest that depolarization of third-order neurons by GABA and glycine is due to at least two mechanisms; a direct postsynaptic effect and an indirect effect. Therefore, in the catfish retina, a mechanism of presynaptic inhibition or disinhibition including the direct postsynaptic effect may exist in the third-order neurons.

• 한국수산과학회지
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• 제48권5호
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• pp.725-730
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• 2015

We observed yellow catfish Pelteobagrus fulvidraco fingerlings cultured in land ponds in Korea swimming in a corkscrew spiral pattern while hanging head-up and tail-down at the water surface, before eventually dying. Externally, these fish displayed “hole in the head” disease, pale gills, and hemorrhages in the base of the pectoral and caudal fins; internally they had liver hemorrhages and kidney discoloration. The bacterium Edwardsiella ictaluri (YCK-01 and YCL-01) was identified in the kidneys and livers of diseased fish via phenotypic characteristics and PCR analysis using the ictaluri-specific primers IVS (an intervening sequence) and IRS (the inter-ribosomal spacer). Infectivity challenges by intraperitoneal and immersion routes showed that a representative bacterial strain (YCK) exhibited strong virulence to yellow catfish, with an LD₅₀ of 3.2×10⁴ CFU/fish and 2.5×10⁶ CFU/mL, respectively. This is the first report of E. ictaluri infection in yellow catfish from Korea.

• 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.

• 한국환경농학회지
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• 제42권4호
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• pp.408-417
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• 2023

This study aimed to investigate the effects of an aquaponics system utilizing catfish recirculating water on the growth and water quality in lettuce and chicory cultivation. After 60 d of catfish cultivation in the BFT-AP, the survival rate was 96.0% and average weight gain was 178.5 g. The WGR grew by 241.4% and the SGR was 3.0%. A comparison between lettuce and chicory cultivation using BFT-AP and hydroponics revealed significant increases in shoot height, leaf count per week, and biomass of the cultivated lettuce and chicory. The SPAD values also increased significantly by 15.4-43.3%. Water quality analysis of the BFT-AP systems and crop cultivation beds showed significant differences, except for K and Na. The average NO₃^- concentration in the sediment pond was significantly higher at 45.3±1.0. Comparison of water temperature, pH, EC, DO, and ORP in the BFT-AP system and crop cultivation beds revealed similar monthly water temperatures from July to September. The pH in the catfish culture pond was 0.3-1.2 lower than that in the crop cultivation beds, and the EC was approximately 0.01- 0.03 dS/m lower in the catfish culture pond than the crop cultivation beds. The monthly average ORP in the catfish culture bed steadily increased to 479.9 mV in October. Bacillus velezensis (AFB2-2) and Chlorella fusca (CF) were applied to the biological activation bed; the population density of CF showed a continuous increase, whereas that of AFB2-2 decreased after 15 d and gradually increased thereafter. Thus, the application of the recirculating aquaponics cultivation technology with catfish (BFT) enhances catfish cultivation and promotes the growth of lettuce and chicory. Therefore, it is considered suitable for the environment-friendly cultivation of lettuce and chicory.

• 한국어병학회지
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• 제15권3호
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• pp.105-110
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• 2002

한국산 어류에 감염된 포자충의 종류와 병해를 조사 할 목적으로 2001년 9월부터 2002년 8월까지 양식중인 정읍산 메기와 만경강 하구의 기수 구역에 서식하는 자연산 문절망둑을 조사하였다. 이 들 어류에서 지금까지 한국 미기록종인 포자충의 감염이 확인되었다. 즉 메기의 장 상피조직에서 Myxobolus miyairii Kudo, 1919가, 문절망둑의 피하 근육조직에서 Henneguya tridentigeri Ozaki & Ishizaki, 1941가 검출되었다. 메기에 기생 된 M. miyairii는 장 상피조직에 42-77 (56) $\mu{m}$ × 59-93(73) $\mu{m}$크기의 백색 영양체가 무수히 관찰되었고, 포자의 길이는 11.0-12.0(11.3) $\mu{m}$이었다. 어체 기생율은 86.7-90%이었으나, 감염어는 별다른 병변을 발견할 수 없었다.

• 한국발생생물학회지:발생과생식
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• 제21권1호
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• pp.79-91
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• 2017

The aim of this study was to compare the efficacy of cryopreservation methods for ex situ conservation of spermatozoa from far eastern catfish, Silurus asotus. The spermatozoa activity index (SAI) and hatching rates were higher in spermatozoa stored in Alserver's solution than those of spermatozoa stored in glucose solution. The SAI and hatching rates in all experimental groups gradually decreased with increasing duration of storage. Additionally, the SAI and hatching rates gradually decreased with increasing thawing temperatures at all storage durations (P<0.05). Based on the SAI and hatching rates, our results suggest that the optimal cryopreservation conditions of catfish spermatozoa involve storage in Alserver's solution with 15% ethylene glycol, and thawing at $25^{\circ}C$. Cryopreservation of spermatozoa is a useful and reliable technique for conserving gene resources and for artificial propagation of far eastern catfish.

• 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.