• Korean Journal of Environment and Ecology
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• v.30 no.1
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• pp.48-57
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• 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
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• v.28 no.6
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• pp.657-663
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• 2014

This study was conducted to investigate the difference in feeding habits of Red-Tongued Viper Snakes, according to available foods sources and areas. The effects of differences in food sources were found on Red-Tongued Viper Snake inhabited in the Jeju Island and its islet Gapado, from May 2006 to Nov. 2010. The food sources for the Red-Tongued viper snake population in the Jeju Island were found to be as follows: Chinese red-headed centipedes (Scolopendra subspinipes mutilans), Jeju Salamanders (Hynobius quelpaertensis), Japanese tree Frogs (Hyla japonica), Narrow-mouthed Toad (Kaloula borealis), Dybowski's Brown Frogs (Rana dybowskii), Black-spotted Pond Frogs (Rana nigromaculata), Smooth Skinks (Scincella vandenburghi), Asian Keelback Snakes (Amphiesma vibakari), Lesser White-toothed Shrews (Crosidura shantungensis), Hallasan Shrews (Sorex caecutiens hallamontanus), and Jeju Striped Field Mice (Apodemus chejuensis). This implies that Red-Tongued Viper Snakes mainly feed on amphibians, reptiles, and small mammals. Among these, amphibians occupied the highest portion at 55.2% followed by mammals at 20.7%, centipedes at 13.8%, and reptiles at 10.3%. On the contrary, Red-tongued viper snake population in Gapado only feed on Chinese red-headed centipedes and Smooth Skinks (S. vandenburghi). Since only a small amount of nutrient can be obtained from Chinese red-headed centipeds or Smooth Skinks, this feeding habit for Red-tongued viper snake would adversely effect on the growth or regeneration. The reason why Red-Tongued viper snake population in the Gapado mainly feed on Lizard and Centipedes in spite of relatively various available food sources, might be due to the low density of other food sources in the Gapado. Red-Tongued viper snake could be feeding on foods that are low in quality but are easily accessible, to minimize energy consumption on searching for other more nutritious foods. A snake tends to select the size of its food depending on the size of its own head. The positive correlation was found between the size of the heads of Red-Tongued viper snakes from the Jeju island and the diameter of their foods. The head size was larger in the males than females in viper snake population from the Jeju Island, which might effect on their selection of foods. However, no significant difference was found between the sizes of the head and the food in the Red-Tongued viper snake population from the Gapado. The findings of this study would provide meaningful data, which directly shows that even within the same viper species they choose different available food sources according to their inhabitance. This leads to their growth and adaptation to their environment which is beneficial for sustaining of its population.

• Animal cells and systems
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• v.3 no.2
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• pp.193-197
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• 1999

A peroxidase-antiperoxidase method was used to detect the cells showing immunoreactivities to six hormone antibodies in the alimentary tracts of six frog species, Rana nigromaculata, R. rugosa, R. amurensis coreana, R. catesbeiana, Bombina orientalis, and Hyla arborea japonica, inhabiting Korea. The cells immunoreactive to gastrin and cholecystokinin-8 were observed in the pylorus of the stomachs and in the small intestines of all frog species examined. In contrast, these somatostatin-immunoreactive cells were identified in the esophagus and the whole gastrointestinal tracts, but were absent from the large intestines in R. rugosa, R. catesbeiana, B. orientalis and H. arborea japonica. The pancreatic polypeptide (PP)-immunoreactive cells represented their distribution limited to the small intestines of R. amurensis coreana and H. arborea japonica, and they were additionally identified in the pylorus of the stomachs in the other four species. Serotonin- and glucagon- Immunoreactive cells revealed different regional distributions in which the former were observed throughout the whole alimentary tracts in all frog species investigated, whereas the latter were not found in these regions at all. Endocrine cells were relatively abundant in the pyloric portion of the stomach compared to other organs. The present study showed that all endocrine cells except for PP had a similar distribution in the alimentary tracts of all frog species used.

• Animal cells and systems
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• v.3 no.3
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• pp.247-252
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• 1999

The aim of this study was to characterize antipredator tactics of anurans and to evaluate the effectiveness of these tactics for predator avoidance in real confrontations. Two types of experiments were conducted. In one experiment, one predator and one prey were placed together for one hour in a small confined space (one-to-one interaction). In another experiment, one predator and several prey were placed together for one day in a large enclosure in a field (field-based interaction). The prey consisted of three anuran species, Rana nigromaculata, R. rugosa, and Bombina orientalls: a snake species, Rhabdophis tigrinus tigrinus, was used as a predator. Results of both experiments demonstrated a range in antipredator responses of the frogs, from toxicity and warning coloration, coupled with slow responses in Bombina to little (or only slight) toxicity, crypsis, and fast take-off responses to the predator in the ranids. oth ranid species exhibited lower survival(57%) than Bombina (95%) in the field-based interaction, suggesting that motor responses of the palatable prey due to attacks of the predator ultimately limited their survival. The jumping of the ranids increased the activity of the predator, which became more likely to strike. Simple crouching(seen in R. rugosa and B. orientalis) and chemical defense (in Bombina) reduced predatory attacks.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.157-163
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• 2012

Oxidative stress has been reported to be one of causes of neuritis. This study examined antioxidative activities of methanol extracts of six amphibian species known to be medicinal animals (Rana catesbeiana, R. coreana, R. rugosa, R. dybowskii, R. nigromaculata, and Hyla japonica) and investigated their effects of inhibiting nitric oxide (NO) production and cytotoxicity on the murine macrophage RAW264.7 cells. As inflammation is closely associated with reactive oxygen species, assays on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, xanthine oxidase inhibitory activity, superoxide anion radical scavenging activity and NO scavenging activity of the extracts of the six species were performed to investigate their antioxidative activity. The results obtained were as follows; All extracts showed antioxidative activity, and the activity of R. dybowskii was the highest in comparison among those. Anti-inflammatory effects of the extracts were also examined, the five extracts except that of R. rugosa did not show cytotoxicity for RAW264.7 cells at the maximal concentration ($1,000{\mu}g\;mL^{-1}$). Selectivity index, meaning NO scavenging activity compared to cytotoxicity, showed the highest level in the extract of R. dybowskii. These results will be very useful basic data for future studies on prevention and treatment of human diseases to understand the biological roles of amphibian extracts throughout the antioxidative or anti-inflammatory pathways.

• Journal of Ecology and Environment
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• v.33 no.3
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• pp.229-236
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• 2010

We conducted field surveys of amphibians and reptiles over a two-year period in 16 lagoons along the eastern coastline of South Korea, and determined the habitat characteristics correlated with the number of amphibian and reptilian species and individuals. We documented 11 amphibian species and 8 reptilian species. The dominant amphibian species was the black-spotted pond frog (Rana nigromaculata), and the dominant reptilian species was the red-eared turtle (Trachemys scripta elegans), an invasive species. Among the 14 habitat characteristics, connectivity to mountainous area significantly affected the number of amphibian and reptilian individuals. Other factors, including emerged plant cover, salinity, pH, the number of birds for amphibians and connectivity to agricultural land, lagoon perimeter length for reptiles also influenced the number of species or individuals of them. Our results demonstrate that these lagoons are home to more amphibians and reptiles than has been previously known. To effectively conserve herpetofauna in the lagoon ecosystem, lagoons as well as surrounding wetlands, grasslands, and mountainous areas should be protected.

• The Korean Journal of Zoology
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• v.3 no.1
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• pp.1-4
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• 1960

The test group and control group, which were grouped with the same weight of five frogs (Rana nigromaculata) respectively, were adapted to light for two hours. Then the anterior lymph heart of the test group were injected with 0.5 cc of 0.1% acetyl choline and 0.5cc of Vitamin B12 (50mc gm/cc). After the frogs of this group were dark-adapted for 90 minutes, their heads were cut off under the dim red light and then their retina removed from eye-balls were extracted with 2% digitonin solution for 20 hours at $0^{\circ}C$. The results of the comparison of these two groups whose optical densities were measured before and after the illumination areas follows : (1) The group which had been injected with 0.5cc of 0.1% acetyl choline solution had the protomotive action on the regeneration of rhodopsin in comparison with the control group. (2) The group which had been injected with 25 mc gm of Vitamin B12 and 0.5cc of 0.1% acetyl choline solution had the controlling action on the regeneration of rhodopsin in comparison with the control group.

• Journal of the Korean Chemical Society
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• v.6 no.1
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• pp.32-35
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• 1962

Six frogs (Rana nigromaculata 25∼40 gm) were adapted to light for 2 hours. Then 0.02 ml of 3% nicotinamide and 0.02 ml of 0.6% folic acid were injected into the vitreous body of the right eye-ball, and 0.02 ml normal saline solution into the vitreous body of the left eye-ball respectively. After dark adaptation for an hour-their heads were cut off under a dim red light (650 $m{\mu}$). The retinae were removed from the left eye-ball for the control group and from the right for the test group respectively. Then rhodopsin was extracted from the retinae with 3 ml of 2% digitonin solution(pH = 7.0) for 17 hours at 0$^{\circ}C$ in the dark. The optical densities before and after the illumination of the extract were measured and compared with those of the control group. The results are as follows: 1) The group which had been injected with 0.02 ml of 3% nicotinamide solution had the promotive action on tile regeneration of rhodopsin in comparison with the control group. 2) The group which had been injected with 0.02 ml of 0.6% folic acid solution had the controlling action on the regeneration of rhodopsin in comparison with the control group.

• Hwankyungkyoyuk
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• v.19 no.1 s.29
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• pp.104-115
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• 2006

This study was conducted to investigate whether attitudes and recognitions of middle and high school students regarding environmental concerns were improved after anuran call monitoring. It was a step toward monitoring local environmental changes with anuran calls. Three-striped pond frogs (Rana nigromaculata), Bullfrogs (R. catesbeiana), and Narrow-mouthed toads (Kaloula borealis) were surveyed to determine local abundance and distribution of them in 12 study sites using their advertising calls. A published booklet, which contains morphological, physiological, ecological, and acoustic information on amphibian species and methods of monitoring anuran calls were provided to monitoring students for identifying the three species. Pretest-posttest were conducted before and after monitoring from 10 April to 28 August in 2005 to determine how the monitoring students changed their attitudes on environmental issues, increased knowledges on amphibians, and improved the understanding on the cause and effect of declining amphibian populations. The amphibian monitoring program was effective to improve the students' attitudes towards conserving environments as well as the students' knowledge on general behavior and ecology of various amphibian species although their understanding about various environmental problems was not. In addition, the program increased the students' understanding on the problems of declining amphibian populations.

• The Korean Journal of Zoology
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• v.39 no.3
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• pp.257-265
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• 1996

Previously, we demonstrated that estradiol (E$_2$) was produced by medium sized follicles of Rana nigromaculata and Rana dybowskii in vitro. Present experiments were carried out to determine when the growing follicles have obtained the ability to produce E$_2$. Follicles in different growth stages were isolated and cultured for 6 hours in the presence or absence of frog pituitary homogenates (FPH, 0.1 pituitary/2m1) or various steroid precursors (200 ng/2m1). levels of progesterone (P$_4$), 17 -hydroxyprogesterone (17$\alpha$-OHP), androstenedione (AD), testosterone Cr) or E$_2$ in the medium were measured by RIA. The smallest follicles failed to produce steroids, whereas the smaller follicles produced considerable amounts of steroids (211 pg/follicle), and the medium sized follicles produced a large amounts of steroids (1653 pg/follicle) in response to FPH. Addition of pregnenolone (P5) resulted in a marked increase in P$_4$ but not in other steroids by the smallest follicles whereas the treatment resulted in a marked increase in P$_4$, 17$\alpha$-OHP, AD, T and E$_2$by the smaller and medium follicles. When the amounts of steroids are calculated on the basis of unit surface area (pg/mm$_2$), the ability of the smallest follicles to produce P$_4$ from P5 was similar to those of smaller and medium sized follicles. However, the smallest follicles failed to metabolize P$_4$ to other steroids whereas the smaller and medium follicles did. Taken together, the data suggest that the smallest follicles do not response to FPH in terms of steroid production but they have capacity to convert P5 to P$_4$ and that the smaller follicles have potential to produce E$_2$ although much less efficient than medium sized follicles.