• 한국습지학회지
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• 제10권3호
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• pp.133-139
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• 2008

도심하천은 도심개발과 오염으로 인해 기능이 점차 상실되고 있다. 본 연구는 도림천의 출현 동물상 및 식물상을 파악하여 도심하천의 건강성을 평가하는 지표종을 발굴하고, 습지보전지역의 가능성을 위한 방안을 토론하였다. 도림천에서 안양천에 이르는 구간에 총 113종의 식물종, 포유류 9종, 조류 23종, 양서류 4종, 파츙류 2종과 어류 2종이 관찰되었다. 육상곤충은 71종이 관찰되었으며, 습지식생은 매우 다양하며 총 4개의 권역으로 나누었으며, 도심하천의 특징을 나타내는 수변지역 및 습지식물권역(습지식물권역, 반습지식물권역, 습지주변초지 지역, 습지주변교목지역)에 대한 관리방안이 도출되었다.

• 한국환경복원기술학회지
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• 제18권1호
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• pp.71-82
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• 2015

Hyla suweonensis is an endemic species and is designated as the only endangered species I among amphibians in 2012 by the Ministry of Environment, however studies about its habitat are lacking. This study was carried out to analyze habitat of H. suweonensis based on the spatial information using Maxent (Maximum entropy model as a species distribution model. We detected 45 present points until 2013 and 10 environmental variables by literature review for the model. The results showed that $429km^2$ (0.95%) of the study area, which was about 7.75% of the total agricultural area, was high possible habitats of H. suweonensis. The habitat of H. suweonensis was analyzed by over $1km^2$ rice paddy fields that were lower elevations, flat slopes, and not fragmented. The distance from forests and rivers was identified as a factor that affects its habitat possibilities. In order to conserve H. suweonensis, a large area of rice paddy fields should be preserved, and especially the area around forests and rivers would be required more intensive management. In addition, to compensate for degraded habitats of H. suweonensis in urban areas like as Suwon city, considering integrated watershed management strategy could be effective in the perspective of ecological habitat network of H. suweonensis.

• 한국습지학회지
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• 제14권4호
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• pp.591-596
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• 2012

홍천강 유역은 우리나라 대표적인 청정지역으로 수생태계의 대표적인 수달이 서식하는 지역이다. 이들 지역에서 서식하는 수달의 서식지분석을 위해 식이물 연구가 수행되었다. 총 478개의 흔적 및 배설물이 사용되었으며, 수달의 식이물 분석 결과 80.5%가 어류인 것으로 조사되었다. 어류 중 이 지역에서 가장 우점하는 갈겨니(Zacco temminckii)의 식이물이 확인되었으며, 양서류 및 조류가 섭식된 것으로 나타났다. 계절적으로는 여름철 식이물의 빈도가 가장 높게 나타났으며 먹이자원이 여름철에 풍부한 것으로 보인다. 군업천과 내촌천의 식이물 구성 및 빈도는 크게 다르지 않았다. 현재 이 지역은 홍천-양양간 고속도로 건설이 진행되는 지역으로 수달 식이물 분석을 통한 인공서식지, 관리방안 도출 등이 수행되어야 한다.

• 한국동물학회지
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• 제23권4호
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• pp.263-272
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• 1980

개구리 2種 (Rana nigromaculata와 Rana plancyi chosenica)과 도룡뇽 (Hynobius leechii)의 胚發生에 EK른 lactate dehydrogenase (LDH)와 malate dehydrogenase (MDH)의 isozyme 組成變化를 polyacrylamide 電氣泳動法으로 조사 분석하고 이를 成體의 몇 器官과 비교하였다. R. nigromaculata에서 LDH의 B subunit의 合成을 지배하는 유전자는 heterozygous이고 H. leechii에서는 A subunit의 合成을 지배하는 유전자가 heterozygousfk고 추정된다. 위의 3種의 兩棲類\ulcorner 胚에서 發生初期에는 LDH-1 (심장형)의 活性이 높으나 發生이 진행됨에 따라 LDH-5 (근육형)의 活性도 점차 증가된다. MDH의 경우 發生初期부터 MDH-m과 MDH-s가 존재하고 발생 全段階를 통하여 그 組成에는 변화가 없으나 MDH-m의 活性이 점차 증가하는 경향을 보인다.

• 대한약리학회지
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• 제11권1호
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• pp.15-18
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• 1975

The effect of skin extracts of Korean amphibian, poisonous snake and fresh-water fish were determined for their caerulein-like action on rabbit gall bladder strips. The isolated gall bladder strips were prepared according to the technique described by Amer and Becvar(1969). The strips were placed in a bath containing 100ml of Locke-Ringer solution maintained at $38^{\circ}C$. Oxygen was continuously bubbled through the solution. The tension of the muscle strip was initially adjusted to 0.7g. The contractile response was measured isometrically by a force-displacement transducer connected to a polygraph. In this rabbit gall bladder strip caerulein produced contraction of CCK-PZ type. The skin extract of Korean amphibian also elicited similar contraction as caerulein, which extracted from Australian amphibian, Hyla caerulea, by Erspamer et al. The calculated amount was approximately $2{\mu}g$ caerulein per gram of skin tissue in Korean amphibian and the potency was about 1/200 of that seen in Australian amphibian. The contraction of gall bladder strip by our amphibians occurs in decreasing order; Rana Nigromaculata coreana Okada, Rana nigromaculata Hallowell, Hyla arborea japonica Gunther and Bombina orientalis Boulenger. The skin extracts of poisonous snake and fresh-water fish produced no caerulein-like activity.

• 한국환경교육학회지:환경교육
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• 제19권1호
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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.

• Journal of Ecology and Environment
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• 제45권1호
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• pp.10-16
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• 2021

Background: Ranavirus is an emerging infectious disease which has been linked to mass mortality events in various amphibian species. In this study, we document the first mass mortality event of an adult population of Dybowski's brown frogs (Rana dybowskii), in 2017, within a mountain valley in South Korea. Results: We confirmed the presence of ranavirus from all collected frogs (n = 22) via PCR and obtained the 500 bp major capsid protein (MCP) sequence from 13 individuals. The identified MCP sequence highly resembled Frog virus 3 (FV3) and was the same haplotype of a previously identified viral sequence collected from Huanren brown frog (R. huanrenensis) tadpoles in South Korea. Human habitat alteration, by recent erosion control works, may be partially responsible for this mass mortality event. Conclusion: We document the first mass mortality event in a wild Korean population of R. dybowskii. We also suggest, to determine if ranavirus infection is a threat to amphibians, government officials and researchers should develop continuous, country-wide, ranavirus monitoring programs of Korean amphibian populations.

• 한국환경복원기술학회지
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• 제25권2호
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• pp.85-92
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• 2022

The amphibian breeding habitat is confirmed by mating call. In some cases, the researcher directly identifies the amphibian individual, but in order to designate the habitat, it is necessary to map the mating call region of the amphibian population. Until now, it has been a popular methodology for researchers to hear mating calls and outline their breeding habitats. To improve this subjective methodology, we developed a technique for mapping mating call regions using Unmanned Aerial Vehicle (UAV). The technology uses a UAV, fitted with a sound recorder to record ground mating calls as it flies over an amphibian habitat. The core technology is to synchronize the recorded sound pressure with the flight log of the UAV and predict the sound pressure in a two-dimensional plane with probability density. For a demonstration study of this technology, artificial mating call was generated by a potable speaker on the ground and recorded by a UAV. Then, the recorded sound data was processed with an algorithm developed by us to map mating calls. As a result of the study, the correlation coefficient between the artificial mating call on the ground and the mating call map measured by the UAV was R=0.77. This correlation coefficient proves that our UAV recording system is sufficiently capable of detecting amphibian mating call regions.

• Journal of Ecology and Environment
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• 제47권2호
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• pp.35-41
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• 2023

Background: Several species of amphibians in agricultural areas are often infected with ranaviruses; however, the biological or ecological factors that cause this infection are not well understood. In this study, we investigated whether local tadpole density, Gosner developmental stage, and weather conditions affected ranavirus infection in Dryophytes japonicus tadpoles in rice paddies over three months. Results: During the study, eight samplings were undertaken between June 6 and August 21, 2022. No die-off of tadpoles occurred, but 20 of 110 tadpoles (18.8%) were found to be infected with ranavirus. The tadpole density at the sampling site and Gosner stage of the sampled tadpoles were not related to the daily ranavirus infection rate. The mean daily highest temperature during the two weeks prior to the sampling date and the mean daily lowest and highest temperatures during the week prior to the sampling date were negatively related to the daily infection rate. Conclusions: Our results suggest that low and extreme temperatures caused by flooding and draining of paddy fields or climate change in summer could be a significant risk factor for ranavirus infection in summer-breeding frogs in agricultural areas.

• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1412-1419
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• 2023

Retroviral integration into ancient vertebrate genomes left traces that can shed light on the early history of viruses. In this study, we explored the early evolution of retroviruses by isolating nine Spuma endogenous retroviruses (ERVs) and one Epsilon ERV from the genomes of Agnatha and Chondrichthyes. Phylogenetic analysis of protein sequences revealed a striking pattern of co-evolution between jawless fish ERV and their host, while shark ERV underwent ancient cross-class viral transmission with jawless fish, ray-finned fish, and amphibians. Nucleotide sequence analysis showed that jawless fish ERV emerged in the Palaeozoic period, relatively later than ray-finned fish ERV. Moreover, codon analysis suggested that the jawless fish ERV employed an infection strategy that mimics the host codon. The genealogical diversity of ERVs in the jawless fish genome highlights the importance of studying different viral species. Overall, our findings provide valuable insights into the evolution of retroviruses and their interactions with their hosts.