• Journal of Marine Life Science
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• v.7 no.2
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• pp.187-195
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• 2022

Crucian carp, Carassius carassius (Weight 28.1±3.7 g, Length 10.0±1.0 cm) were challenged with Aeromonas hydrophila at 0, 2.0×10⁴, 2.0×10⁵, 2.0×10⁶, 2.0×10⁷ CFU/ml for 2 weeks. The lethal concentration 50 (LC₅₀) at 2 weeks of C. carassius challenged with A. hydrophila was 19.776×10⁵ CFU/ml. In hematological parameters, the hemoglobin and RBC counts were significantly decreased by A. hydrophila challenge, whereas there was no significant change in hematocrit. The inorganic plasma components such as magnesium and calcium were significantly decreased. In organic plasma components, glucose and cholesterol were significantly increased by A. hydrophila challenge, whereas total protein was significantly decreased. In enzymatic plasma components, ALP (Alkaline phosphatase) were significantly increased by A. hydrophila challenge. The results of this study suggest that the A. hydrophila challenge to C. carassius induced the significant physiological changes in the hematological parameters and plasma components as deadly pathogenic bacteria.

• Environmental Analysis Health and Toxicology
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• v.18 no.1
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• pp.21-25
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• 2003

카바메이트계 농약인 카보푸란은 어류에 대한 독성이 매우 높으며, 낮은 농도에서 어류의 척추기형이나 행동이상을 유발한다. 이러한 카보푸란의 독성기전을 밝히기 위한 일환으로 신경물질대사와 관련이 깊은 acetylcholine esterase(AChE)와 monoamine oxidase(MAO)에 미치는 농약의 효과를 송사리(Oryzias latipes; Medaka fish)를 이용하여 평가하였다. Medaka fish에 대한 카보푸란의 반수치사농도(LC$_{50}$)는 2.5 ppm이었으며, 1 ppb 카보푸란에 24시간 노출된 경우, AChE 효소활성이 머리와 몸통부위에서 각각 30, 20%씩 감소되었다. 한편, MAO 효소활성은 카보푸란의 농도가 증가함에 따라 머리부위에서는 감소한 반면, 몸통부위에서는 증가하는 경향을 보였다. 특히 카보푸란의 농도가 1 ppb에서도 송사리의 MAO 효소활성이 영향을 받는 것으로 나타나, 카보푸란에 의한 송사리의 행동이상은 AChE 활성 뿐 아니라 MAO활성의 변화에 의한 복합적인 효과일 가능성이 높다.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.706-714
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• 2017

An investigation of the effects of Pb for domestic anuran embryos were evaluated with the Frog Embryo Teratogenesis Assay; Xenopus (FETAX). Depending on the species, the difference between the embryo size and the embryonic development time was determined. As a result, mortality and malformation rates were increased, malformation patterns were changed and larval body length were decreased in a dose dependent manner of the Pb. The half maximal lethal concentration ($LC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.58, 0.49, 0.52, $0.54mg\;L^{-1}$, respectively. The half maximal effective concentration ($EC_{50}$) of the Bufo gargarizans, Hyla japonica, Rana nigromaculata and Bombina orientalis were 0.35, 0.74, 0.30, $0.29mg\;L^{-1}$, respectively. The teratogenic index (TI) were 1.66 in the Bufo gargarizans, 1.81 in the Hyla japonica, 1.73 in the Rana nigromaculata and 1.86 in the Bombina orientalis, respectively. Therefore, the Pb seems likely to have a teratogenic effect in all four species' embryonic development. The Bombina orientalis was the most sensitive to the Pb. This means that the difference between the different species, even if they have all been exposed to the same concentration of pollutants depending on the species. The result above show that the Pb acts as a teratogenic agent in the development of the four domestic frog species.

• Journal of fish pathology
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• v.19 no.3
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• pp.277-284
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• 2006

Application of wood vinegar in fish farms has been used for the disinfection of pathogenic microorganisms and the treatment of infectious diseases. This study was performed to know the acute toxicity of wood vinegar to carp Cyprinus carpio, flounder Paralichyhus olivaceus, rock fish Sebastes schlegeli and black sea bream Pagrus major. The 24 hr, 48 hr and 96 hr LC50 respectively were: carp 1243, 1143 and 1016 ppm; flounder 1397, 1253 and 1226 ppm; rock fish 1058, 993 and 967 ppm; and black sea bream 650, 616 and 596 ppm. Death and survival of fish exposed to lethal concentrations of wood vinegar were apparently related to massive necrosis, fusion and epithelial lifting of gill lamellar epithelium, suggesting the osmotic imbalance and lack of oxygen uptake.

• Journal of the Korean Institute of Gas
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• v.17 no.4
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• pp.9-17
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• 2013

Butanethiol is known as a typical odorant with hydrogen sulfide, methyl mercaptan, methyl sulfide, but on the physical and chemical properties and biological hazard assessment, including inhalation toxicity data are very scarce. Butanethiol as a colorless transparent liquid, and has physic-chemical characteristics with flash point as $-23^{\circ}C$ and strong fire risk, boiling point $84-85^{\circ}C$, vapor pressure 80.71 mmHg ($25^{\circ}C$), freezing point $-140.14^{\circ}C$. From whole body exposure with SD rats, the $LC_{50}$ is above 2,500 ppm (9.22mg/L), and then it is classified as the acute toxic chemical (inhalation) category 4 according to the governmental notification No. 2012-14.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.98-105
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• 2005

The relative sensitivity of two freshwater non- biting midges, Chironomus yoshimatsui Martin and Sublette and C. riparius Meigan, was examined for lead, cadmium, and mercury in water- only exposures. Two endpoints were compared to assess toxicity 48 h and 96 h after exposure: Acute toxicity ($50\%$ lethal concentration: $LC_50$) and behavioral toxicity ($50\%$ effective concentration: $EC_{50}$). for the behavioral toxicity, reduction of swimming performance of two midge species in the treated conditions was compared to that in the untreated control. The sensitivities differed depending on the species and heavy metals, although some trends emerged. $LC_50$ values in C. yoshimatsui to cadmium and lead were always higher than those in C. riparius with increasing toxicity, regardless of the exposure times. The opposit was true for the mercury treatment. Similar trends were observed in the $EC_{50}$ values. The $EC_{50}$ values were always lower than the $LC_50$ values in all the treatment cases (midge species, heavy metals, and exposure times). These results indicate that the two midge species respond to the heavy metals differently: C. riparius is sensive to cadmium and lead and C. yoshimatsui to mercury. Behavioral toxicity such as swimming performance can be an effective endpoint for assessing heavy metal toxicity in water.

• Applied Microscopy
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• v.42 no.2
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• pp.53-59
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• 2012

We evaluated the level of toxicity by LC50 and investigated the mechanism of brain impairment and GFAP expression by light and fluorescence microscopes in the pale chub, Zacco platypus, treated with fenvalerate. Survival rate was decreased according to the rise of fenvalerate concentration, and LC50 concentration was $27.79{\mu}g/L$. Apoptosis was increased according to the rise of fenvalerate concentration by TUNEL assay which determine apoptotic cell death population. Also, GFAP expression was increased in the periventricular zone. These results suggest that apoptosis might be a major mechanism to brain impairment of the pale chub by fenvalrerate. Increased GFAP expression in the periventricular zone would be an index of brain impairment. Taken together, this study might contribute to reveal the pathological mechanism of fish brain impairment by insecticide of pyrethroid, and to be an useful basic data for preservation of aquatic ecosystem.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.256-265
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• 2023

Chlorothalonil is continuously introduced into the marine environment and has significant toxic effects on various marine organisms, however, research on its effect on seaweed is limited. Therefore, we analyzed the impact of chlorothalonil on the early life stages of major aquaculture species in Korea, Undaria pinnatifida. U. pinnatifida female gametophytes were exposed to different concentrations of chlorothalonil (0, 0.03, 0.05, 0.10, 0.20, and 0.40 mg L^-1), and their survival rate and relative growth rate were analyzed. The no observed effect concentration (NOEC), lowest observed effect concentration (LOEC), and median lethal concentration (LC50) for female gametophyte survival were determined as 0.05, 0.10, and 0.141(0.121-0.166)mg L^-1. NOEC, LOEC, and median effective concentration (EC50) for relative growth rate were 0.10, 0.20, and 0.124 (0.119-0.131) mg L^-1. Therefore, female gametophytes of U. pinnatifida are expected to experience toxic effects at concentrations above 0.05-0.10 mg L^-1 of chlorothalonil. These research findings are anticipated to serve as crucial reference data for evaluating the effects of chlorothalonil on the health of U. pinnatifida in the early life stages.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.427-438
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• 2023

Biocide dichlofluanid breaks down quickly and accumulates easily in sediment, potentially causing a persistent impact on various marine organisms. We analyzed the potential toxicity of dichlofluanid on major aquaculture species in Korea, Undaria pinnatifida. Female gametophytes of U. pinnatifida were exposed to dichlofluanid at concentrations of 0, 1, 2, 4, 8, 16, and 32 mg L^-1, and their survival and relative growth rate were analyzed. The no observed effect concentration(NOEC), lowest observed effect concentration (LOEC), and median lethal concentration (LC₅₀) for female gametophyte survival were determined as 1, 2, and 10.82 (95% CI: 8.87-13.23) mg L^-1, respectively. The NOEC, LOEC, and median effective concentration (EC₅₀) for relative growth rate were 1, 2, and 6.58 (95% CI: 6.03-7.17) mg L^-1, respectively. Female gametophytes of U. pinnatifida were expected to experience toxic effects at concentrations above 2 mg L^-1 of dichlofluanid. These research findings are expected to serve as important reference data for evaluating the toxicity effects of U. pinnatifida in its early life stages when exposed to dichlofluanid.

• Journal of fish pathology
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• v.35 no.1
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• pp.65-75
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• 2022

Mirror carp, Cyprinus carpio nudus (weight 26.2±3.1 g, length 11.8±0.5 cm) were exposed to waterborne total ammonia nitrogen (TAN) at 0, 2, 4, 8, 16, 32, 64 and 128 mg TAN/L. The lethal concentration 50 (LC₅₀) of mirror carp, C. carpio nudus exposed to waterborne ammonia was 60.38 mg TAN/L. The red blood cell (RBC) count was significantly reduced by ammonia exposure, whereas there was no significant changes in the hemoglobin concentration and hematocrit value. In the plasma components, glucose, total protein, aspartate aminotransferase (AST) and alkaline phosphatase (ALP) were significantly increased by ammonia exposure. The results of this study suggest that the ammonia exposure to C. carpio nudus affects the survival rates, hematological parameters and plasma components as toxicity.