• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.45-51
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• 1984

This study was performed to evaluate the aquatoxicity of 5 chemicals (butachlor, isoprothiolane, probenazole, carbofuran, and cartap) to carp (Cyprinus carpio), discuss the impact on the $96 hr-LC_{50}$ values of the chemicals with the exposure time. In butachlor, we also compared the acute toxicity values between two exposure system, the continuous flow system and static state system, and measured the dissolved oxygen concentrations in the two systems. The acute toxicity values (96 hr-LC50 values) of the 5 chemicals were 0.25 ppm in butachlor, 10.0 ppm in isoprothiolane, 6.2 ppm in probenazole, 1.40 ppm in carbofuran, and 0.64 ppm in cartap, respectively. We also found that the $LC_{50}$ values were downed with increase of the exposure time.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.158-163
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• 2003

This study was conducted te evaluate the effect of organotin compounds on rotifer(Brachionus plicatilis), which is important as food organism of aqua-cultured fish and shellfish. To evaluate the texicities of tributyltin compounds such as tributyltin chloride (TBTC), tributyltin oxide (TBTO), tributyltin acetate (TBTA) and tributyltin benzoate (TBTB), and triphenyltin compounds such as triphenyltin chloride (TPTC), triphenyltin fluoride (TPTF), triphenyltin hydroxide (TPTB), the survival rates of rotifer exposed to these compounds were measured as the 96 hr-$LC_{50}$. Exposed concentrations Were from 0.5 to 8 bbp depending on compounds. Based on 96 hr-$LC_{50}$ Value, the Order of toxicity in TBTs was TBTA(1.1 ppb)>TBTC (2.0)>TBTB (3.3)>TBTO(5.6), and that in TPTs was TPTF (1.0)$\geq$TPTC(1.1)>TPTH(1.6). Triphenyltin compounds were slightly higher toxic than tributyltins. The toxicity is likely to depend on alkyl or aryl group other than halogen or the other substituted radicals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.124-133
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• 1996

A herbivorous copepod, Tigriopus japonicus, was tested to study its acute and chronic responses to Cd tonicity. Under $20^{\circ}C,\;96hr-LC_{50}$ of T. japonicus in medium with $32\%_{\circ},\;26\%_{\circ},\;and\;18\%_{\circ}$ salinity were 11.1 ppm, 13.7 ppm, and 9.7 ppm, respectively. The $96hr-LC_{50}$ in medium with $32\%_{\circ},\;26\%_{\circ},\;and\;18\%_{\circ}$ salinity increased to 21.6 ppm, 15.0 ppm, and 11,0 ppm, respectively under $10^{\circ}C$ condition. Oxygen consumption rates during 96hrs exposure to Cd toxicity decreased more sharply at $20^{\circ}C$ than those at $10^{\circ}C$. Survival rate and $250dys-LC_{50}$ of T. japonicus in medium with $32\%_{\circ}$ salinity, in concentration of Cd 4 ppm were $5\%$ and 0.05 ppm, respectively under $10^{\circ}C$, and $0\%$ and 0.20 ppm under $20^{\circ}C$. It was that the copepod selectively feed on Skeletonema costatum, Nitzschia pungens, N. seriata, and Rhizosolenia hebetata f. semispina.

• Journal of Environmental Health Sciences
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• v.15 no.2
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• pp.97-106
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• 1989

This experiment was performed to study the acute toxic effects of mereuric chloride(HgCl$_{2}$) in goldfish (Carassius aurams). In the study, Lc$_{50}$ values were determined for each 24, 48, 72 ,and 96-hr and mercury bioassay during the tests were performed. in five parts gill, kidney, liver, muscle and egg. The results isummarized were as follows 1. In the range of acute lethal toxicity for goldfish was 0.15-1.50 mg/l and the Lc$_{50}$ values decreased with exposure time. 2. The Lc$_{50}$ values of HgCl$_{2}$ for goldfish at 24, 48, 72 and 96 hour were 0.64, 0.53, 0.46, and 0.39 mg/l, respectively. 3. In the 400 $\mu$g/l treatment group, the average levels of mercury residues in the gill, kidey, liver, muscle and egg during 96 hour were 107.02 $\mu$g/g, 8.65 $\mu$g/g, 6.87 $\mu$g/g, 0.61 $\mu$g/g, and 0.82 $\mu$g/g, respectively. 4. The mercuny residues of gill was up to 12-175 times greater than mercury contents found in the other tissues.

• 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.

• Journal of Environmental Health Sciences
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• v.24 no.3
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• pp.99-106
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• 1998

This study was performed to investigate the bioconcentration of dichlorvos, methidathion and phosalone in zebrafish (brachydanio rerio), red sword tail(Xiphophorus hellieri). The fishes were exposed to 0.05 ppm, 0.01 ppm, 0.50 ppm, one-hundredth concentration of 96-hrs LC$_{50}$ and one-thousandth concentration of 96-hrs LC$_{50}$ and test periods were 3, 5 and 8 days. The deputation rate of each pesticide from the whole body of fish was determined over the 24-hr period after treatment. Obtained results are summerized as follows: In the case of dichlorvos, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were increased as increasing test concentration. In the case of same experimental concentrations, dichlorvos concentration in zebrafish extract and BCF$_{s}$ of dichlorvos were decreased as proloning test periods, especially dropped after 5days. Dichlorvos concentration in red sword tail extract were increased as increasing test concentration, lyat BCF$_{s}$ in concentration of 0.05 ppm, 0.01 ppm and one-hundredth of 96-hrs LC$_{50}$ were decreased. Methidathion and phosalone concentration in zebrafish extract in zebrafish extract were increased as increasing test concentration, but there was little difference in BCF$_{s}$. In the case of same experimental concentrations, there were little differences in BCF$_{s}$ and concentration in zebrafish extract. In the case of red sword tail, it was impossible to calculate on BCF$_{s}$ data because test concentration was under the detecting limit on GC or test fish were die. Determined deputation rate conatant were highest on dichlorvos, and followed by methidathion, and phosalone. The results of determining depuration rate of these pesticides showed that the high BCF in fish might be due to the slow depuration rate in fish, it is thought to be responsible for vapor pressure, water solubility and partition coefficient. It is suggested that one-hundredth concentration of 96-hrs LC$_{50}$ will be proper test concentration because one-thousundth of LC$_{50}$ was under the detecting limit on GC. Dichlorvos, methidathion and phosalone, organophosphorous pesticides, were examined to their BCF$_{s}$ and depuration rates by means of fish test.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.113-117
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• 1979

The short-term acute toxicities of mercury, cadmium and copper for the clam, Meretrix lusoria were determined from 28 June to 15 July, 1978. In the test with mercury and copper, the rate ot mucus excretion increased gradually at a higher concentration. But the clams did not excrete mucus in the solutions of cadmium and natural sea water. The rate of mucus excretion in mercury was $42.9\%$, and that in copper was $14.3\%$ in a test solution of 1mg/l. mercury was more toxic than copper. The median lethal concentration after 96 hours (96 hr-Lc 50) was 0.67mg/l in mercury, 7.04mg/l in copper and 7.10mg/l in cadmium. Consequently it was found that mercury was the most toxic substance and cadmium was the least. meanwhile, it was considered that exposure time by stimulation in a fixed concentration caused the test animals to respond.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.5
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• pp.380-384
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• 2004

The toxic impact of parathion on bagrid catfish (Pseudobagrus fulvidraco) juvenile was examined 96 hr $LC_{50}$ value of parathion estimated as 1 90 mg/L. Chronically, bagrid catfish were exposed for 30 days to concentrations of parathion, i.e. 63, 95, 190 and $380\;{\mu}g/L$, representing 3.3, 5.0, 10.0 and $20.0{\%}$ of the 96 hr $LC_{50}$. Survival rate was significantly affected by the concentration over $63\;{\mu}g/L$ after 10 days. Growth rate, specific growth rate (SGR) and feed efficiency were reduced in time as concentration dependent manner. Growth rates of the exposed groups were significantly reduced as $28.06-60.63{\%}$ to the control fish, SGR was decresed as $1.50-4.72{\%}$ and feed efficiency was declined as $6.10-11.90{\%}$. It can be concluded that if p. lulvidraco is chronically exposed to parathion over $63\;{\mu}g/L$ concentration, the physiological damages might affect growth factors of the fish.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.124-129
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• 1988

Prolonged aquatic toxicity tests (7-days) of six pesticides to the freshwater fish Oryzias latipes were performed to confirm the adequacy of the exposure times, 48-hr or 96-hr, which has been required by the protocols for the aquatic acute toxicity test. The toxicity curves were plotted for each chemical, and the significance of the difference between lethal threshold concentrations and 48-hr or 96-hr LC50's was analysed statistically. The lethal threshold concentrations of butachlor, fenobucarb, and chlorothalonil were clearly defined on the 5th day, 2nd day, and 2nd day at 0.53mg/1, 10.3mg/l, and 0.085mg/1, respectively. But the toxicity curves of alachlor, diazinon, and iprobenfos continued with no threshold for 7 days. Four out of six test pesticides failed to show the threshold concentration during the 96-hr exposure time. Therefore, the results of the acute toxicity test using 48-hr or 96-hr exposure time would not describe the ideal toxicity of pesticides. It is recommended that the prolonged exposure should be continued long enough to define the threshold adequately.