• Journal of Aquaculture
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• v.11 no.3
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• pp.401-419
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• 1998

The structure of benthic algal flora and feeding behavior of sea urchins (Anthocidaris crassispina and Hemicentrotus pulcherrimus), were investigated from the eight different locations along the coast of Cheju Island, Korea. Biomass distribution and dominance of the algal communities were studied in relation to the gut contents and population parameters of the sea urchins. As a result, although the largest algal biomass and biological characteristics of sea urchins, such as test diameter, test hight, body weight, gonad weight, etc. This inhdicated that sea urchins would not be dependednt sorely on the abundance of algal foods, and they might feed on other food items. In order to know such a trend with regard to food selectivity, the diets consumed by sea urchins were analyzed, and it was found that they were composed of benthic and drifted algae, various animal components (sponges, bryozoans, crustaceans, and various unidentified capsulated eggs, etc.) and biets turned out to be smaller than might be expected, and it is postulated that sea urchins were not likely to be the major grazing animals for the formation of algal bed and also canopy deterioration, so-called "white incrustation."

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.705-711
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• 2016

In this experiment, embryos of Asian toad, Bufo gargarizans, were investigated to evaluate toxicity of chemicals along FETAX(Frog Embryo Teratogenesis Assay-Xenopus) protocol. Asian toad, Bufo gargarizans, embryos incubated and investigation of Zn and Benomyl effect by probit analysis. As a result, depends on the concentrations of Zn and Benomyl, mortality and malformation rates were increases and larval body length were decreased. The teratogenic concentration($EC_{50}$) of Zn and Benomyl were 2.3, $1.0mg/{\ell}$, respectively and the embryo lethal concentration($LC_{50}$) Zn and Benomyl were 10.3, 6.9, respectively. The teratogenic index(TI) were 4.4 in Zn and 6.7 in Benomyl, thus showed teratogenicity in embryonic development of B. gargarizans. These results reveal that Zn and Benomyl in this experiment suppressed the development of embryos at relatively low concentration. Much of B. gargarizans embryos can be secured, and easy to incubate. In addition, mortality, malformation ratios, malformation patterns and growth rates are similar to the results from the other assay systems. Therefore, the B. gargarizans embryo teratogenesis assay system could be a useful tool to evaluate toxicity of pollutants in environment.

• Korean Journal of Environment and Ecology
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• v.33 no.2
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• pp.178-186
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• 2019

This study used the probit analysis to evaluate the toxicity of three chemicals - benomyl (Germicide), carbofuran (insecticide), and thiobencarb (herbicide) - with the FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol using the incubated embryos of tree frog, Hyla japonica. The results showed that the larval body length decreased while the mortality and malformation rates increased as the concentrations of benomyl, carbofuran, and thiobencarb increased. The teratogenic concentration ($EC_{50}$) of benomyl, carbofuran, and thiobencarb were 1.00, 0.58, 4.75 mg/L, respectively, indicating that the malformation of larvae was the most sensitive to carbofuran. The embryo lethal concentration ($LC_{50}$) was 7.04, 28.71, and 16.12mg/L, respectively, indicating that benomyl showed the lowest embryo lethal concentration. The teratogenic index (TI) was 7.04 in Benomyl, 49.50 in Carbofuran, and 3.39 in Thiobencarb, indicating that the TI values were above 1.5, which is the criterion of teratogenicity, for all three chemicals. All three pesticides examined by this study were considered to be the most teratogenic substances, and the carbofuran was the most potent teratogen.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.15-26
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• 2014

The black soldier fly, Hermetia illucens, larvae may depend on indigenous bacteria in the intestine to feed and digest diverse food sources. To prove this hypothesis, we isolated and identified the intestinal bacteria of the black soldier fly for their digestive and antimicrobial abilities. The last instar larvae had long digestive tracts, which were about seven times longer than its body length. An individual of H. illucens larvae possessed a total of $5.0{\pm}10^6$ bacteria in the whole intestine, of which more than 98% bacteria were located in the hindgut. Three different bacterial isolates cultured on nutrient agar (NA) medium were detected in the intestine and identified as Morganella morganii, Providencia rettgeri and Bacillus halodurans by Biolog microbial identification system. Analysis of 16S rDNA sequences of the intestinal bacteria detected the additional bacteria of Proteus mirabilis, Providencia alcalifaciens, and Providencia sp. These intestinal bacteria cultured on NA medium exhibited high resistance to 4 antibiotics and inhibited growth of other microbes which are mainly plant pathogens. Also, these bacteria exhibited catalytic activities to degrade cellulose, lipid, proteins, and carbohydrates. These results suggest that H. illucens larvae possess intestinal bacteria that may play crucial roles in their digestive physiology.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.1
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• pp.30-37
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• 2006

Black rockfish and goldeye rockfish are commercially important fish species due to the increasing demand in Korea. When estimating the abundance of stocks for these species acoustically, it is of crucial importance to know the target strength(TS) to length dependence. In relation to these needs, TS measurement was conducted on black rockfish and goldeye rockfish in an acrylic salt water tank using 70kHz and 120kHz split beam echo sounders. The TS for these two species under the controlled condition was simultaneously measured with the swimming movement by DVR system and analyzed as a function of fish length(L). The results obtained are summarized as follows: The best fit regression of TS on fish length of black rockfish was TS=19.38 Log(L, cm)-70.46 ($r^2=0.71$) at 70kHz and TS=22.39 Log(L, cm)-70.40 ($r^2=0.64$) at 120kHz and in the standard form TS=20 Log(L, cm)-71.29 ($r^2 = 0.70$) at 70kHz and TS=20 Log(L, cm)-66.88 ($r^2=0.57$) at 120kHz. The best fit regression of TS on fish length of goldeye rockfish was TS=17.10 Log(L, cm)-68.28 ($r^2=0.37$) at 70kHz and TS=24.39 Log(L, cm)-73.74 ($r^2=0.59$) at 120kHz and in the standard form TS=20 Log(L, cm)-72.03 ($r^2=0.32$) at 70kHz and TS=20 Log(L, cm)-67.68 ($r^2=0.64$) at 120kHz. An empirical model for fish TS(dB) averaged over the dorsal aspect of 115 fishes of black rockfish and goldeye rockfish and which spans the fish length(L, m) to wavelength($\lambda$, m) ratio between 8 and 30 was derived : TS=34.12 Log(L)-14.12 Log($\lambda$)-23.83, ($r^2=0.90$).

• Journal of Ginseng Research
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• v.23 no.4
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• pp.235-238
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• 1999

ATP-sensitive $K^+$ channels $(K_{ATP})$ are expressed in vascular smooth muscle cells, skeletal muscle cells, pancreatic ${\beta}$ cells, neurons and epithelial cells. $K_{ATP}$ contributes to regulate membrane potential to control vascular tone, to protect myocardial ischemia, and to regulate insulin secretion in pancreatic ${\beta}$ cells. We previously demonstrated that ginseng saponins and ginsenoside $Rg_3$ activated maxi $Ca^{2+}-activated\;K^+$ channel, and this might cause vasodilation. Because $K_{ATP}$ plays an important roles to regulate the resting membrane potential in vascular smooth muscle cells, we investigated whether ginsenoside $Rg_3$ produces vasodilation by activating $K_{ATP}$ We showed in this study that $K_{ATP}$ is expressed in rabbit coronary artery smooth muscle cells. $K_{ATP}$ was inwardly rectifying and was inhibited by intemal application of ATP. Micromolar minoxidil activated, but glyburide inhibited the activity of $K_{ATP}$ Ginsenoside $Rg_3$ relieved inactivaiton of whole-cell $K_{ATP}$ current without affecting the peak amplitude of $K_{ATP}$ currents presumably due to more opening of the channels.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.689-696
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• 1997

The effects of Aralia canescens and Phellodendron amurense(AP) extracts on the experimental diabetes in ICR mice were investigated. 96male ICR mice were induced diabetes mellitus by intrape-ritoneal streptozotocin injection(75mg/kg B.W.) and divided into two injection groups which are 5 day injection and 10 day injection group. Then, each injection group was subdivided into 8 groups of 6 animals repspectively. CIC served as control and CI1, CI2 and CI3 were treated with 50, 150, 250mg/kg B.W. of AP extracts powder in 0.9% NaCl solution. Animals of groups DIC, DI1, DI2 and DI3 were strepto-zotocin-induced diabetes. DIC served as diabetic control and the rest groups received 50, 150, 250mg/kg B.W of AP extracts powder in saline solution respectively. The body weight, liver and kiney weight changes and blood levels of glucose, cholesterol and triglyceride were measured. Thiobarbituric acid reactive substance(TBARS), and glutathione reductase(GR) and glutathione peroxidase(GPx) activities were also measured for determining antioxidant effects. AP extracts increased the body weight in diabetic groups. The liver and kidney weight/100g B.W. in DIC group were greater than those of normal ICR group but after AP extracts injection, liver and kidney weight were decreased significantly. These effects were more efficient at 10 days injection group. The total, LDL, VLDL cholesterol and triglyceride levels were significantly higher in DIC group and the extent of decrement responded to AP injection dose. The contents of TBARS and antioxidant enzyme activities were relatively decreased after AP extracts injection. These results suggest that the intraperitoneally administered AP extracts may have not only hypoglycemic effect but act as antioxidants by reducing lipid peroxidation.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.675-681
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• 2012

In this experiment, I investigated toxicity evaluation of chemicals using domestic frog embryos, along FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol. I investigated $Cu^{2+}$ and Tebuconazole effect on the tree frog, Hyla japonica, embryos by probit analysis. Mortality and malformation rates increased and larval body length decreased depending on the concentrations of $Cu^{2+}$ and Tebuconazole. The teratogenic concentration ($EC_{50}$) of $Cu^{2+}$ and Tebuconazole were 0.05, 5.0mg/${\ell}$, respectively and the embryo lethal concentration ($LC_{50}$) of $Cu^{2+}$ and Tebuconazole were 0.16, 38.5, respectively. The teratogenic index (TI) appeared 3.0 in $Cu^{2+}$ and 7.7 in Tebuconazole, which showed teratogenicity in embryonic development of Hyla japonica. These results reveal that $Cu^{2+}$ and Tebuconazole in this experiment suppressed the development of embryos at relatively low concentration. Much of Hyla japonica embryos can be secured, and easy to incubate. In addition, mortality, malformation ratios, malformation patterns and growth rates are similar to the results from the other assay systems. Therefore, the Hyla japonica embryo teratogenesis assay system could be a useful tool to evaluate toxicity of pollutants in environment.

• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.207-215
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• 2020

In this experiment, investigated toxicity evaluation of chemicals using Asian toad embryos, along FETAX(Frog Embryo Teratogenesis Assay-Xenopus) protocol. Asian toad, Bufo gargarizans embryo incubated and investigation of Benomyl(Germicide), Carbofuran(Insecticide) and Thiobencarb(Herbicide) effect by probit analysis. As a result, depends on the concentrations of Benomyl, Carbofuran and Thiobencarb, along mortality and malformation rates were increases and larval body length were decreased. The teratogenic concentration(EC₅₀) of Benomyl, Carbofuran and Thiobencarb were 1.03, 8.74, 4.98mg/ℓ, respectively. And when exposed to Benomyl, larvae responded most sensitively to malformations. Embryo lethal concentration (LC₅₀) Benomyl, Carbofuran and Thiobencarb were 7.26, 560.72, 16.87mg/ℓ, respectively. And Benomyl were at the lowest concentration of lethal the embryos. The teratogenic index(TI) were 7.05 in Benomyl, 64.16 in Carbofuran and 3.39 in Thiobencarb, thus TI values were above 1.5, which is the criterion of teratogenicity. Three of the pesticides used in this study were considered to be a teratogenic substances and Carbofuran was the most potent teratogen. And more specific researches are needed to investigate the effects of pesticides on the embryo development of toads and amphibians and their mechanism.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.231-237
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• 2012

Toxicity of $Ni^{2+}$ and Tebuconazole were investigated via FETAX (Frog Embryo Teratogenesis Assay-Xenopus) protocol using domestic frog embryos. Embryos of Black-spotted pond frog, Rana nigromaculata, were incubated and toxic effects of $Ni^{2+}$ and Tebuconazole were investigated by probit analysis. As a result, mortality and malformation rates were increased and larval body length was decreased in a dose dependant manner of $Ni^{2+}$ and Tebuconazole. The half maximal effective concentration ($EC_{50}$) of $Ni^{2+}$ and Tebuconazole were 0.07, $12.7mg\;L^{-1}$, respectively and the half maximal lethal concentration ($LC_{50}$) of $Ni^{2+}$ and Tebuconazole were 4.2, 39.1, respectively. The teratogenic index (TI) were 61.4 in $Ni^{2+}$ and 3.1 in Tebuconazole, respectively. These results reveals that $Ni^{2+}$ and Tebuconazole suppress the development of Black-spotted pond frog embryos at the low concentration as showing teratogenic effects in other assay system. Therefore, teratogen assay system using the Rana nigromaculata embryos could be useful as a tool to evaluate the toxicity of the pollutants in environment.