• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.2
• /
• pp.95-107
• /
• 2016

The gold-spotted pond frog(Pelophylax chosenicus) classified as an Anura in Amphibia is sharply decreasing due to various changes of habitats environment, and designated as IUCN Red List Threatened species(VU; Vulnerable) internationally and domestic endangered species Class-II; therefore, it's in urgent need of the research on habitats restoration of the gold-spotted pond frog in order to prevent its extinction. This study was carried out to verify the effect after restoration by introducing the inhabitation elements deducted by the literature research and a field survey on the habitats for the gold-spotted pond frog in danger of regional extinction in the urban area of Ansan city, Gyeonggi-do, Korea. Accordingly, the capacity for bio-species was increased by expanding the area of habitats into $11,845m^2$, and securing the place for hibernation and corridors and discharge within the habitats, etc. As a result of the monitoring the number of individuals increased by 9.5 times as the reproductive success rate of the gold-spotted pond frog got higher, and by virtue of improvement in the habitats, biodiversity increased to 183 species(4 species of amphibians and reptiles, 4 species of mammals, 17 species of birds, 53 species of insects(terrestrial/Benthic), 4 species of fish, and 102 species of plants). It might be possible to verify the restoration effect of the habitats through continuous monitoring, and suggest the restoration model on the habitats for continuously survivable the gold-spotted pond frog in the urban area by deducting the matters to be improved.

• Korean Journal of Environmental Biology
• /
• v.21 no.2
• /
• pp.203-207
• /
• 2003

Amphibian biodiversity, community structure and habitats were surveyed in the Mt. Myungji area from April 2002 to March 2003. During the survey period 2orders, 4 families, 7 species of amphibians were observed. Bombina orientalis (DI =45.1%) was dominant and Bufo stejnegeri (DI = 12.8%), Rana rugosa and Rana dybowskii (DI = 9.9% each) Rana nigromaculata and Rana huanrenensis (DI 1.4% each), and Onycodactylus fisheri (DI = 7.0%) followed. Frequency of occurrence of O. fisheri and B. stejnegeri was largely different according to the altitude and human residence in their habitats.R. nigromaculata and R. huanrenensis showed low frequency of occurrence (<10%) suggesting the decrease in habitation density in this area. The species richness (R'), general diversity (H'), and evenness (E') of amphibians in this area were 0.98, 2.12, and 0.76, respectively, suggesting relatively healthy condition of amphibian community in this area.

• Animal cells and systems
• /
• v.10 no.4
• /
• pp.203-209
• /
• 2006

Azoles are widely used antifungal agents, which inhibit the biosynthesis of fungal cell-membrane ergosterol. In this study, using an amphibian follicle culture system, the effects of azoles on follicular steroidogenesis in frogs were examined. Itraconazole (ICZ), clotrimazole (CTZ) and ketoconazole (KCZ) suppressed pregnenolone ($P_5$) production by the follicles ($ED_{50};\;0.04_{\mu}M,\;0.33_{\mu} M,\;and\;0.91_{\mu}M$, respectively) in response to frog pituitary homogenates (FPH). However, fluconazole (FCZ), miconazole (MCZ) and econazole (ECZ) were not effective in the suppression of $P_5$ production. Not all the azoles examined suppressed the conversion of exogenous $P_5$ to progesterone ($P_4$) (by $3{\beta}$- HSD) or $P_4$ to $17{\alpha}$-hydroxyprogesterone ($17{\alpha}$-OHP) (by $17{\alpha}$-hydroxylase), or androstenedione (AD) to testosterone (T) (by $17{\beta}$-HSD). In contrast, CTZ, MCZ and ECZ in medium partially suppressed the conversion of $17{\alpha}$-OHP to AD (by C17-20 lyase) ($ED_{50};\;0.25{\mu} M,\;4.5{\mu}M,\;and\;0.7{mu}M$, respectively) and CTZ, KCZ, ECZ and MCZ strongly suppressed the conversion of exogenous T to estradiol ($E_2$) (by aromatase) ($ED_{50};\;0.02{\mu}M,\;8{\mu}M,\;0.07{\mu}M,\;0.8{\mu}M$, respectively). These results demonstrated that some azole agents strongly suppress amphibian follicular steroidogenesis and particularly, P450scc and aromatase are more sensitive to azoles than other steroidogenic enzymes.

• Animal cells and systems
• /
• v.10 no.4
• /
• pp.211-217
• /
• 2006

Heavy metals are well known as important environmental pollutants and also considered as endocrine disrupters. This study was performed to evaluate the direct effects of heavy metals such as cadmium (Cd), zinc (Zn), mercury (Hg), lead (Pb), cobalt (Co), and arsenic (As) on the various steroidogenic enzymes in frog ovarian follicles. Ovarian follicles from Rana catesbeiana were isolated and cultured for 18 hours in the presence of frog pituitary homogenate (FPH, 0.05 gland/ml) or various steroid precursors with or without heavy metals (0.01-100 ${\mu}M$), and steroid levels in the follicle or culture medium were measured by radioimmunoassay (RIA). Thus, the steroidogenic enzyme activities were indirectly evaluated by measuring the converted steroid levels from the added precursor steroid. Among heavy metals, Hg, Cd and Zn significantly inhibited FPH-induced pregnenolone ($P_5$) production by the follicles ($EC_{50},\;4.0{\mu}M,\;25.6{\mu}M\;and\;5.7{\mu}M$, respectively ), and also suppressed the conversion of testosterone (T) to estradiol $17{beta}\;(E_2)\;(EC_{50},\;4.2{\mu}M,\;7.5{\mu}M\;and\;80.0{\mu}M) while Pb, Co and As are not or less effective in the inhibition. Other enzymes such as $C_{17-20}$ lyase and $17{\beta}$-hydroxysteroid dehydrogenase ($17{\beta}$-HSD) were suppressed only in the high concentration of Hg, Cd and Zn. Taken together, these data demonstrate that cytochrome P450 side chain cleavage (P450scc) and aromatase are much more sensitive to heavy metals than other steroidogenic enzymes and Hg, Cd and Zn show stronger toxicity to follicles than other heavy metals examined.

• Korean Journal of Environment and Ecology
• /
• v.20 no.4
• /
• pp.400-406
• /
• 2006

To investigate the incidence of the road-kill of amphibians and reptiles in Songgye valley, Woraksan National Park, a survey of Songgye valley was conducted from January, 2003 to December, 2005. Before the investigation, the survey area was divided into 50 sites at 300m intervals. As a result, road-kill by vehicles were confirmed to affect 40% of the amphibians and 68.3% of the reptiles among the total species in the Woraksan National Park. The most affected species was Rana dybowskii, with a frequency of 94.9% among the total number of road-killed Individuals. The highest road-kill rate occurred between April to May, every year. Therefore, it is necessary to construct an eco-bridge and to perform the continuous ecological monitoring for the conservation of R. dybowskii including other species.

• Animal cells and systems
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2007

Recently, we have shown that some endocrine disruptors, heavy metals, organotins and azoles suppressed steroidogenic enzymes such as P450 side-chain cleavage enzyme (P450scc) and aromatase in bullfrog ovarian follicles. In the present study, by using an amphibian ovarian follicle culture system, we examined the effects of these endocrine disruptors on maturation and ovulation of oocytes from Rana dybowskii in vitro. Ovarian fragments or isolated follicles were cultured for 24 h in a medium containing frog pituitary homogenate (FPH) or progesterone ($P_{4}$) with or without endocrine disruptors, and oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation were examined. Among the organotins, tributyltin (TBT) strongly inhibited both FPH-and $P_{4}-induced$ oocyte maturation ($ED_{50}$:0.6 and 0.7 ${\mu}M$, respectively); however, tetrabutyltin (TTBT) and dibutyltin (DBT) showed only partial suppression, while monobutyltin (MBT) showed no inhibitory effect. All of the organotins suppressed $P_{4}-induced$ oocyte ovulation very effectively at a low concentration, and TBT and DBT exerted an inhibitory effect on FPH-induced ovulation. Among the heavy metals, mercury (Hg), cadmium (Cd) and cobalt (Co) were very effective in inhibiting FPH-induced oocyte maturation and ovulation, while lead (Pb), arsenite (As) and zinc (Zn) were less effective. However, all of the heavy metals suppressed FPH-induced oocyte ovulation at a high dose ($100{\mu}M$). Among the azoles, itraconazole (ICZ), ketoconazole (KCZ) and clotrimazole (CTZ) effectively inhibited FPH-induced oocyte maturation and ovulation, while econazole (ECZ), miconazole (MCZ) and fluconazole (FCZ) were considerably less effective. These results demonstrated that the abovementioned endocrine disruptors exhibited differential effects on oocyte maturation and ovulation in amphibian follicles and that the frog ovarian culture system could be used as an effective experimental tool to screen and evaluate the toxicity of various endocrine disruptors in vitro.

• Korean Journal of Environment and Ecology
• /
• v.30 no.1
• /
• pp.48-57
• /
• 2016

The distribution of fish (Cobitidae and Cyprinidae) and amphibians together with related environmental factors were surveyed at 30 randomly selected rice-fields (15 flooded unmanaged rice fields (FUR) and 15 unflooded managed rice fields (UMR)) near the Yedang reservoir in Korea, eight times from May to August in 2012. The total number of species captured from the entire survey area was 13 species with 8 families of fish and 5 species of amphibians. The number of species of Cyprinidae fish captured in FUR was higher than that in UMR. Upon the comparative analysis on the distribution of fish and amphibians in FUR and UMR, it was found that the number of Cyprinidae fish captured in FUR was significantly higher than that in UMR while the number of Cobitidae fish captured in UMR was higher than that in FUR. According to the analysis on the environmental factors that affect the distribution of fish, Cyprinidae fish tend to appear in rice-fields, that were flooded in winter, near the Yedang reservoir while Cobitidae fish tend to appear in rice fields that draws its water supply from forest reservoir and have a good water drainage system. In case of amphibians, the number of tadpoles captured in UMR was higher than that in FUR. Rana catesbeiana was dominant in FUR and Rana nigromaculata was dominant in UMR. Upon the analysis on the environmental factors that affect the distribution of tadpoles, it was found that Rana catesbeiana tadpoles tend to appear in rice fields, that were flooded in winter, near Yedang reservoir while Rana nigromaculata tadpoles tend to appear near mountains and far from the Yedang reservoir.

• Korean Journal of Environment and Ecology
• /
• v.25 no.4
• /
• pp.601-613
• /
• 2011

The purpose of this study is to provide an protected wildlife species and potential habitats in Seoul through the overall present status of the species which live in Seoul. This study was performed in Seoul, the entire area of which is 605.52 $km^2$. We analyzed a total of 57 studies, including academic papers and research reports, for the natural ecology in Seoul. As for the results from the study, it was found that a total 1,907 species from 5 taxa were inhabiting and growing within the area. Among the total, plants of 1,656 species accounted for 86.7%, 197 species of wild birds made up 10.3%, 29 species of amphibians and reptiles consisted of 1.5%, and 27 species of mammalia totaled 1.4%. A total of 440 species except foreign species and species legally preserved by the Ministry of Environment, common species and uncertain species were selected as primary candidates. By taxon, it shows 212 species of plants, 180 species of wild birds, 24 species of mammalia, and 24 species of amphibians and reptiles. For extensive research subjects and research data limited in certain insect family, analysis by literature for discovered insects was excluded. The selection criteria for the second candidate species was based on extinction crisis, rarity, historicity and locality, academic value, habitat specificity, etc. The second candidate species from the primary species were selected through taxon experts' evaluations. As for the results of the selection of the second candidates, a total 77 species were selected through the experts' evaluations. Each species by taxon was 25 species for plants, 21 species for wild birds, 5 for mammalia, 10 for amphibians and reptiles and 16 species for insects. A site investigation for the second candidates was conducted to select the final candidate species. For the target areas, the habitats of the second candidates given by the literature and 46 potential areas in Seoul, which show good natural resistance, were finally selected. From the result of the site investigation, it was found that 14 species of plants, 19 species of wild birds, 2 species of mammalia, 4 species of amphibians and reptiles, and 16 species of insects were actually inhabiting Seoul; thus, the final 55 protected species were selected.

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2003.10a
• /
• pp.128-129
• /
• 2003

Cricket (Gyilus bimacutus) is mass-bred in 6 time cycles per one year in insect farms. They are used as dry or live foods for animals, tropical fish, reptile and amphibians. Therefore, it is necessary to study the genotoxicity of whole bodies of G. bimaculatus. The aim of this present study was to evaluate the genotoxicity of the G bimaculatus extract with three methods, Ames test, chromosome aberration test in Chinese hamster ovary cells in vitro and micronucleus (MN) test in vivo which involve the different test systems (bacteria, mammalian cells and mice nuclei). (omitted)

• Korean Journal of Environmental Biology
• /
• v.24 no.2 s.62
• /
• pp.160-165
• /
• 2006

The purpose of this study was to ascertain the prey composition and utilization of the Eurasian otter, Lutra lutra, in the ecosystem conservation region of the Seomjin River. The study was conducted for a 12-month period from March 2003 to February 2004 by spraints analysis and an investigation using artificial holts. We found seasonal variation in the number of spraints and composition of prey items. Fish were the main prey items throughout the period (82%), and other prey items included birds (14%), amphibians (2%) and arthropods (1%). In addition to prey identification, we investigated habitat utilization by otters through spraints distribution. The traces of otters were discovered in five of the six total artificial holts. However, the utilization of the artificial holts in the study area seemed to be limited as evidenced by the low frequency of traces in the holts.