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Papers by daesik park

Research paper thumbnail of 보문 : 국립공원 내 파충류 자원의 효율적인 관리를 위한 PIT(passive integrated transponder) tag과 무선추적방법(radio telemetry)의 적용

본 연구는 PIT tag (passive integrated transponder)과 무선추적법(radio telemetry)을 오대산국립공원과 월악산국립공원에 서식하고 있는... more 본 연구는 PIT tag (passive integrated transponder)과 무선추적법(radio telemetry)을 오대산국립공원과 월악산국립공원에 서식하고 있는 파충류에 적용한 후, 이를 평가하여 효과적으로 국립공원 내 파충류 자원관리 방안을 모색하기 위하여 수행되었다. PIT tag은 현재까지 알려진 파충류 개체표시법 중에서 가장 효과적인 방법으로 2006년 3월부터 2008년 10월까지 오대산국립공원과 월악산국립공원의 조사지역에 출현한 모든 137마리의 뱀류를 대상으로 적용하였다. 무선추적 연구는 월악산국립공원에서 서식하고 있는 황구렁이(Elaphe schrenckii anomala) 2마리를 대상으로 2007년 9월부터 2008년 11월까지 실시하였다. 연구결과, 두 곳의 국립공원 지역에서 연구기간 동안 17마리가 재 포획되어 평균 12.40%의 재포획률을 보였으며, 재 포획된 개체들의 자료를 통하여 누룩뱀(Elaphe dione)과 쇠살모사(Gloydius ussuriensis) 성체의 SVL 증가를 성공적으로 확인하였다. 무선추적을 통하여 확인된 황구렁이 수컷의 행동권 면적은 MCP=389,600 m2, Kernel 95%=471,800 m2, 암컷은 MCP=162,500 m2, Kernel 95%=208,700 m2인 것으로 확인되었다. 국립공원 내에서 보호와 관리가 필요한 종 혹은 멸종위기대상 종인 파충류를 대상으로 PIT tag과 무선추적을 적용한다면 공원 내 파충류의 효율적인 관리 및 보존방안을 마련하는 데 중요한 기초자료를 제공할 수 있을 것으로 생각된다.

Research paper thumbnail of 청원군에 소재한 금개구리(Rana plancyi chosenica) 개체군의 번식동태

환경부지정 멸종위기 II급 종인 금개구리(Rana plancyi chosenica)의 번식생태를 연구하기 위하여 충북 청원군 강내면에 위치하는 묵논형 습지에 있는 금개구리 개... more 환경부지정 멸종위기 II급 종인 금개구리(Rana plancyi chosenica)의 번식생태를 연구하기 위하여 충북 청원군 강내면에 위치하는 묵논형 습지에 있는 금개구리 개체군을 2007년 4월부터 2008년 11월까지 총 207일에 걸쳐서, 모음담장과 주머니함정을 설치하여 모니터링을 실시하였다. 금개구리들은 봄철 4월 20일부터 6월 13일 사이에 번식지로 이동하였으며, 가을철 동면지 이동은 9월 21일부터 11월 16일 사이에 일어났다. 서식지 내·외로의 이동은 2007년과 가을 이동과 2008년 봄 이동 시 공히 강수와 높은 양의 상관을 보였지만, 기온, 수온, 상대습도와는 유의미한 상관관계를 보이지 않았다. 금개구리들은 이동 시 주로 논의 언덕이나 묵논과 연결된 이동경로를 다른 경로보다 선호하여 사용하는 것으로 나타났다. 번식지 내·외로의 이동순서와 개체의 신체 요소와는 2007년 봄에는 번식지 내·외로의 이동순서와 개체의 몸길이(snout-vent length)와 양의 상관을 보였으며, 이동순서와 몸무게와는 2008년 봄을 제외한 모든 경우에 양의 상관을 보여, 작은 개체들이 먼저 출현하고 먼저 동면지로 이주하는 경향을 보였다. 금개구리 암컷은 수컷에 비하여 유의미하게 큰 것으로 확인되었으며, 가을철 동면지 이주 시 20 mm SVL 크기 이하의 작은 개체들의 수가 2007년, 2008년 공히 소폭 증가하여, 개체군 내에 성공적인 번식이 일어나고 있음을 알 수 있었다. 이러한 연구결과는 금개구리 야외 개체군을 보존하는 기초자료로 활용할 수 있을 것이다.

Research paper thumbnail of Seasonal Changes in the Basic Reproductive Physiology of the Endangered Reeves’ Turtle (Mauremys reevesii) Based on Hibernation or Nonhibernation

Korean Journal of Environment and Ecology, 2016

Research paper thumbnail of Report of a Dicephalic Steppes Ratsnake (Elaphe dione) Collected in South Korea

Asian Herpetological Research, 2013

In this report, we describe morphological characteristics of a dicephalic Steppes Ratsnake (Elaph... more In this report, we describe morphological characteristics of a dicephalic Steppes Ratsnake (Elaphe dione) collected from the wild in 2011 in South Korea. The specimen has two heads and two long necks. Unlike normal individuals, the dicephalic snake has divided ventral scales under the necks of the bifurcated columns. The snoutvent length (SVL) and overall total length of the individual are shorter than those of normal snakes of the same age. Nevertheless, the counts of nine different scale types that are often used for classification are all within the ranges of normal individuals. As far as we know, this is the first detailed morphological description of a dicephalic E. dione in the scientific literature.

Research paper thumbnail of Daily temperature fluctuations unpredictably influence developmental rate and morphology at a critical early larval stage in a frog

BMC Ecology, 2013

Background Environmental temperature has profound consequences for early amphibian development an... more Background Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized the influence of temperature on development in amphibians have failed to incorporate the realities of diel temperature fluctuations (DTF), which can be considerable for pond-breeding amphibians. Results We evaluated the effects of different ecologically relevant ranges of DTF compared with effects of constant temperatures on development of embryos and larvae of the Korean fire-bellied toad (Bombina orientalis). We constructed thermal reaction norms for developmental stage, snout- vent length, and tail length by fitting a Gompertz-Gaussian function to measurements taken from embryos after 66 hours of development in 12 different constant temperature environments between 14°C and 36°C. We used these reaction norms as null models to test the hypothesis that developmental effects of DTF are...

Research paper thumbnail of Interactions between a small chronic increase in diel water temperature and exposure to a common environmental contaminant on development of Arizona tiger salamander larvae

General and comparative endocrinology, Jan 16, 2016

Global climate change leading to increased temperatures may affect shifts in physiological proces... more Global climate change leading to increased temperatures may affect shifts in physiological processes especially in ectothermic organisms. Temperature-dependent shifts in developmental rate in particular, may lead to life-long changes in adult morphology and physiology. Combined with anthropogenic changes in the chemical environment, changes in developmental outcomes may affect adult functionality. The purpose of this study is to determine 1) if small increases in diel water temperature affect the development of Arizona tiger salamander (Ambystoma tigrinum nebulosum) larvae, and 2) if this change interacts with exposure to the common environmental thyroid disrupting compound, perchlorate. Larvae between Watson and Russell developmental stages 8-13 were exposed to ammonium perchlorate (AP) at doses of 0, 20 or 200ppb and then raised at either ambient or a 0.9°C elevated above ambient temperature for 81days in outdoor enclosures. During the first 5 treatment weeks, AP treatment induced...

Research paper thumbnail of High ranavirus infection rates at low and extreme temperatures in the tadpoles of Japanese treefrogs (Dryophytes japonicus) that breed in rice paddies in the summer

Journal of Ecology and Environment

Background: Several species of amphibians in agricultural areas are often infected with ranavirus... more 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.

Research paper thumbnail of Prevalence of Ranavirus Infection in Three Anuran Species across South Korea

Viruses

To cope with amphibian die-offs caused by ranavirus, it is important to know the underlying ranav... more To cope with amphibian die-offs caused by ranavirus, it is important to know the underlying ranavirus prevalence in a region. We studied the ranavirus prevalence in tadpoles of two native and one introduced anuran species inhabiting agricultural and surrounding areas at 49 locations across eight provinces of South Korea by applying qPCR. The local ranavirus prevalence and the individual infection rates at infected locations were 32.6% and 16.1%, respectively, for Dryophytes japonicus (Japanese tree frog); 25.6% and 26.1% for Pelophylax nigromaculatus (Black-spotted pond frog); and 30.5% and 50.0% for Lithobates catesbeianus (American bullfrog). The individual infection rate of L. catesbeianus was significantly greater than that of D. japonicus. The individual infection rate of P. nigromaculatus was related to the site-specific precipitation and air temperature. The individual infection rate gradually increased from Gosner development stage 39, and intermittent infection was confirme...

Research paper thumbnail of Distribution and Prediction Modeling of Snake Roadkills in the National Parks of South Korea: Odaesan National Park1a

Korean Journal of Environment and Ecology

In this study, we collected snake roadkill data from 2006 to 2017 and developed a species distrib... more In this study, we collected snake roadkill data from 2006 to 2017 and developed a species distribution model to identify the pattern of snake roadkill and predict the potential hotspot of snake roadkill in the Odaesan National Park of South Korea. During the study period, snake roadkills occurred most frequently on the road, which passes through between forest and stream at an altitude of about 600 m. The modeling result showed that the occurrence probability of snake roadkill was high on a road with a gentle slope at a distance of 25 m from the stream and an altitude of 600 m. The most susceptible regions for snake roadkill in the Odaesan National Park were located on National Route 6, about 2.2 km and 11.7 km away from the southern border of the park, and on Local Road 446, 3.44 km away from the southern border of the park. The results of this study suggest

Research paper thumbnail of Comparison of detective ranavirus with major capsid protein gene from infected frogs (Pelophylax nigromaculatus and Lithobates catesbeianus) in South Korea

Journal of Ecology and Environment

Ranaviruses are a primary cause of amphibian extinctions. More consistent ranavirus-infection rep... more Ranaviruses are a primary cause of amphibian extinctions. More consistent ranavirus-infection reports and genetic characterizations of identified viruses are urgently needed, particularly from Asian countries. The objectives of this study were to obtain the partial major capsid protein (MCP) gene sequences (506 bp) of the ranavirus responsible for infecting frogs in South Korea, as our previous research had confirmed using qPCR, and to evaluate their genetic relationships with other previously reported ranavirus sequences. Three different ranavirus MCP sequences were obtained from Pelophylax nigromaculatus and Lithobates catesbeianus. All six different types of MCP sequence from the ranavirus identified in South Korea to date belonged to the Frog virus 3 (FV3)-like virus group in the genus Ranavirus. To better understand the origin and spread of ranaviruses in South Korea, further infection reports and full genome analyses of the identified ranaviruses are needed.

Research paper thumbnail of Movement Patterns of Juvenile Loggerhead Turtles (Caretta caretta L. 1758) and Green Turtles (Chelonia mydas L. 1758) Hatched in Captivity and Released in the Korean Waters

Animals

With most sea turtle populations declining, activities to conserve their habitat and nesting grou... more With most sea turtle populations declining, activities to conserve their habitat and nesting grounds and restore their populations are being implemented worldwide. To preserve the Northwestern Pacific populations, the National Marine Biodiversity Institute of Korea has been releasing artificially propagated sea turtles, but whether these individuals join the wild population remains unknown. The present study aimed to determine the movement patterns of artificially propagated juvenile loggerhead (Caretta caretta) and green (Chelonia mydas) turtles fitted with satellite transmitters on their carapaces and released in the waters of Jeju or Yeosu, Republic of Korea, between August 2018 and April 2022. Loggerheads traveled northward to the East Sea, whereas green turtles moved west or southwest. Two 36-month-old and two 48-month-old loggerheads moved toward their potential nursery grounds and toward their feeding grounds, respectively. Three green turtles with a curved carapace length (C...

Research paper thumbnail of Additional file 1 of First detection of ranavirus in a wild population of Dybowski's brown frog (Rana dybowskii) in South Korea

Additional file 1 PCR detection of the MCP sequence of ranavirus from the liver tissues of dead R... more Additional file 1 PCR detection of the MCP sequence of ranavirus from the liver tissues of dead Rana dybowskii's adults. The numbers on the bands represent individual frogs. P, positive MCP sequence control of ranavirus from Rana huarenensis tadpoles and N, negative control, which used nuclease-free water instead of extracted DNA in PCR process.

Research paper thumbnail of Additional file 1 of Prediction of present and future distribution of the Schlegel's Japanese gecko (Gekko japonicus) using MaxEnt modeling

Additional file 1: Table S1. Description of the 19 climate variables and their component score co... more Additional file 1: Table S1. Description of the 19 climate variables and their component score coefficient matrix from the principal component analysis (using the RStoolbox package of the statistical program R) of the climate variables. Table S2. The MODIS Land Cover Type Product (MCD12Q1) codes and the labels for each code. Table S3. Raw data of the environmental and climate variables, used in Gekko japonicus distribution modeling at present and future. Figure S1. Response curves of the seven important environmental variables that affect the distribution of suitable habitats of Gekko japonicus: A) Climate PCA1 (temperature seasonality), B) Altitude, C) Distance to the nearest urban and built-up area, D) Slope, E) Climate PCA2 (annual precipitation), F) Land cover type (MCD12Q1), and G) NDVI. Figure S2. Jackknife evaluations of the relative importance of the seven variables affecting the distribution of suitable habitats of Gekko japonicus.

Research paper thumbnail of Multiple Paternity in the Endangered Amur Ratsnake (Elaphe schrenckii)

Russian Journal of Herpetology, 2017

We determined the occurrence of multiple paternity and minimum number of fathers in eight clutche... more We determined the occurrence of multiple paternity and minimum number of fathers in eight clutches of the endangered E. schrenckii in South Korea using offspring obtained from a captive breeding program between 2014 and 2016. By examining five microsatellite loci and comparing the result with the characteristics of mother, egg and offspring we found that seven clutches out of eight (87.5%) showed multiple paternity with mean number of minimum fathers per clutch as 2.3 based on the alleles of fathers, which confirmed sire of offspring. The degree of multiple paternity was negatively correlated with the infertility rate of eggs, but not with any aspects of offspring, suggesting that multiple mating functions to assure the fertilization of eggs. Based on this result, we recommend that each female in the breeding program should be allowed to mate with more than three different males to keep appropriate levels of genetic variability in offspring.

Research paper thumbnail of First detection of ranavirus in a wild population of Dybowski’s brown frog (Rana dybowskii) in South Korea

Journal of Ecology and Environment, 2021

Background Ranavirus is an emerging infectious disease which has been linked to mass mortality ev... more 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 o...

Research paper thumbnail of Predation of the Japanese keelback (Hebius vibakari Boie, 1826) by the Slender racer (Orientocoluber spinalis Peters, 1866)

Journal of Ecology and Environment, 2021

Background The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassifie... more Background The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassified to the new genus Orientocoluber from Hierophis. Ecological knowledge of this species is limited due to its highly mobile behavior. On 17 July 2020, we captured a female O. spinalis on Oeyeon Island, Boryeong-si, Republic of Korea, and collected its feces for a diet analysis. We observed snake scales from the collected feces and subsequently determined the prey species through morphological and molecular methods. Results We initially hypothesized that the extracted fecal sample scales belonged to H. vibakari, due to their thin keel and rhombus shape. We also amplified H. vibakari DNA from the extracted fecal sample using Illumina sequencing methods. Our morphological and molecular results suggest that O. spinalis predates H. vibakari on Oeyeon Island. Conclusion This is the first report of O. spinalis predating another snake species, ophiophagy, and implies that H. vibakari may be a cru...

Research paper thumbnail of Defining Conservation Requirements for the Suweon Treefrog (Dryophytes suweonensis) Using Species Distribution Models

Diversity, 2021

Numerous amphibian species are declining because of habitat loss and fragmentation due to urbaniz... more Numerous amphibian species are declining because of habitat loss and fragmentation due to urbanization of landscapes and the construction of roads. This is a mounting threat to species restricted to habitats close to urban areas, such as agricultural wetlands in North East Asia. The Suweon treefrog (Dryophytes suweonensis) falls into the list of species threatened with habitat loss and most populations are under threat of extirpation. Over the last decades, sub-populations have become increasingly disconnected and specifically the density of paved roads has increased around the only site connecting northern and southern Seoul populations. We surveyed this locality in Hojobeol, Siheung, Republic of Korea in 2012, 2015 and 2019 to first confirm the decline in the number of sites where D. suweonensis was present. The second objective was to analyze the habitat characteristics and determine the remaining suitable habitat for D. suweonensis through a species distribution model following ...

Research paper thumbnail of Preferred Feeding Sites and Prey of the Adult Gold-spotted Pond Frog, Rana plancyi chosenica

Journal of Ecology and Environment, 2007

Research paper thumbnail of Genetic diversity and inferred dispersal history of the Schlegel’s Japanese Gecko (Gekko japonicus) in Northeast Asia based on population genetic analyses and paleo-species distribution modelling

Mitochondrial DNA Part A, 2020

To understand the genetic diversity and dispersal history of Schlegel's Japanese gecko (Gekko jap... more To understand the genetic diversity and dispersal history of Schlegel's Japanese gecko (Gekko japonicus), we performed genetic analyses and paleo-species distributional modelling. For the genetic analysis, we analyzed mitochondrial DNA (mtDNA) (cytochrome b [Cytb] and NADH dehydrogenase 2 [ND2]) and seven microsatellite loci of 353 individuals from 11 populations (2 east coast China, 4 west and central coast Japan and 5 Korea). For the paleo-species distribution modelling, we used 432 occurrence data points (125 China, 291 Japan and 16 Korea) over the Pleistocene and Holocene. China is inferred to be the source population, which had higher genetic diversity (mtDNA) and more private alleles (mtDNA) compared to Japanese and Korean populations. Differences between the three counties were very small in the mtDNA haplotype network despite some genetic structure among the three countries. Microsatellite analysis inferred that genetic exchange has actively occurred among the Chinese, Japanese and Korean populations. Suitable habitats in Japan should have been plentiful by the mid-Holocene, but have only recently become available in Korea. These results suggest that dispersal of G. japonicus occurred after the Holocene warming from the east coast of China to the west and central coasts of Japan and Korea, and gene flow is actively occurring among the three countries.

Research paper thumbnail of Analysis of the Correct and Incorrect Reports on the Observation and Capture of Sea Snakes in the Coasts of South Korea

Korean Journal of Environment and Ecology, 2017

Research paper thumbnail of 보문 : 국립공원 내 파충류 자원의 효율적인 관리를 위한 PIT(passive integrated transponder) tag과 무선추적방법(radio telemetry)의 적용

본 연구는 PIT tag (passive integrated transponder)과 무선추적법(radio telemetry)을 오대산국립공원과 월악산국립공원에 서식하고 있는... more 본 연구는 PIT tag (passive integrated transponder)과 무선추적법(radio telemetry)을 오대산국립공원과 월악산국립공원에 서식하고 있는 파충류에 적용한 후, 이를 평가하여 효과적으로 국립공원 내 파충류 자원관리 방안을 모색하기 위하여 수행되었다. PIT tag은 현재까지 알려진 파충류 개체표시법 중에서 가장 효과적인 방법으로 2006년 3월부터 2008년 10월까지 오대산국립공원과 월악산국립공원의 조사지역에 출현한 모든 137마리의 뱀류를 대상으로 적용하였다. 무선추적 연구는 월악산국립공원에서 서식하고 있는 황구렁이(Elaphe schrenckii anomala) 2마리를 대상으로 2007년 9월부터 2008년 11월까지 실시하였다. 연구결과, 두 곳의 국립공원 지역에서 연구기간 동안 17마리가 재 포획되어 평균 12.40%의 재포획률을 보였으며, 재 포획된 개체들의 자료를 통하여 누룩뱀(Elaphe dione)과 쇠살모사(Gloydius ussuriensis) 성체의 SVL 증가를 성공적으로 확인하였다. 무선추적을 통하여 확인된 황구렁이 수컷의 행동권 면적은 MCP=389,600 m2, Kernel 95%=471,800 m2, 암컷은 MCP=162,500 m2, Kernel 95%=208,700 m2인 것으로 확인되었다. 국립공원 내에서 보호와 관리가 필요한 종 혹은 멸종위기대상 종인 파충류를 대상으로 PIT tag과 무선추적을 적용한다면 공원 내 파충류의 효율적인 관리 및 보존방안을 마련하는 데 중요한 기초자료를 제공할 수 있을 것으로 생각된다.

Research paper thumbnail of 청원군에 소재한 금개구리(Rana plancyi chosenica) 개체군의 번식동태

환경부지정 멸종위기 II급 종인 금개구리(Rana plancyi chosenica)의 번식생태를 연구하기 위하여 충북 청원군 강내면에 위치하는 묵논형 습지에 있는 금개구리 개... more 환경부지정 멸종위기 II급 종인 금개구리(Rana plancyi chosenica)의 번식생태를 연구하기 위하여 충북 청원군 강내면에 위치하는 묵논형 습지에 있는 금개구리 개체군을 2007년 4월부터 2008년 11월까지 총 207일에 걸쳐서, 모음담장과 주머니함정을 설치하여 모니터링을 실시하였다. 금개구리들은 봄철 4월 20일부터 6월 13일 사이에 번식지로 이동하였으며, 가을철 동면지 이동은 9월 21일부터 11월 16일 사이에 일어났다. 서식지 내·외로의 이동은 2007년과 가을 이동과 2008년 봄 이동 시 공히 강수와 높은 양의 상관을 보였지만, 기온, 수온, 상대습도와는 유의미한 상관관계를 보이지 않았다. 금개구리들은 이동 시 주로 논의 언덕이나 묵논과 연결된 이동경로를 다른 경로보다 선호하여 사용하는 것으로 나타났다. 번식지 내·외로의 이동순서와 개체의 신체 요소와는 2007년 봄에는 번식지 내·외로의 이동순서와 개체의 몸길이(snout-vent length)와 양의 상관을 보였으며, 이동순서와 몸무게와는 2008년 봄을 제외한 모든 경우에 양의 상관을 보여, 작은 개체들이 먼저 출현하고 먼저 동면지로 이주하는 경향을 보였다. 금개구리 암컷은 수컷에 비하여 유의미하게 큰 것으로 확인되었으며, 가을철 동면지 이주 시 20 mm SVL 크기 이하의 작은 개체들의 수가 2007년, 2008년 공히 소폭 증가하여, 개체군 내에 성공적인 번식이 일어나고 있음을 알 수 있었다. 이러한 연구결과는 금개구리 야외 개체군을 보존하는 기초자료로 활용할 수 있을 것이다.

Research paper thumbnail of Seasonal Changes in the Basic Reproductive Physiology of the Endangered Reeves’ Turtle (Mauremys reevesii) Based on Hibernation or Nonhibernation

Korean Journal of Environment and Ecology, 2016

Research paper thumbnail of Report of a Dicephalic Steppes Ratsnake (Elaphe dione) Collected in South Korea

Asian Herpetological Research, 2013

In this report, we describe morphological characteristics of a dicephalic Steppes Ratsnake (Elaph... more In this report, we describe morphological characteristics of a dicephalic Steppes Ratsnake (Elaphe dione) collected from the wild in 2011 in South Korea. The specimen has two heads and two long necks. Unlike normal individuals, the dicephalic snake has divided ventral scales under the necks of the bifurcated columns. The snoutvent length (SVL) and overall total length of the individual are shorter than those of normal snakes of the same age. Nevertheless, the counts of nine different scale types that are often used for classification are all within the ranges of normal individuals. As far as we know, this is the first detailed morphological description of a dicephalic E. dione in the scientific literature.

Research paper thumbnail of Daily temperature fluctuations unpredictably influence developmental rate and morphology at a critical early larval stage in a frog

BMC Ecology, 2013

Background Environmental temperature has profound consequences for early amphibian development an... more Background Environmental temperature has profound consequences for early amphibian development and many field and laboratory studies have examined this. Most laboratory studies that have characterized the influence of temperature on development in amphibians have failed to incorporate the realities of diel temperature fluctuations (DTF), which can be considerable for pond-breeding amphibians. Results We evaluated the effects of different ecologically relevant ranges of DTF compared with effects of constant temperatures on development of embryos and larvae of the Korean fire-bellied toad (Bombina orientalis). We constructed thermal reaction norms for developmental stage, snout- vent length, and tail length by fitting a Gompertz-Gaussian function to measurements taken from embryos after 66 hours of development in 12 different constant temperature environments between 14°C and 36°C. We used these reaction norms as null models to test the hypothesis that developmental effects of DTF are...

Research paper thumbnail of Interactions between a small chronic increase in diel water temperature and exposure to a common environmental contaminant on development of Arizona tiger salamander larvae

General and comparative endocrinology, Jan 16, 2016

Global climate change leading to increased temperatures may affect shifts in physiological proces... more Global climate change leading to increased temperatures may affect shifts in physiological processes especially in ectothermic organisms. Temperature-dependent shifts in developmental rate in particular, may lead to life-long changes in adult morphology and physiology. Combined with anthropogenic changes in the chemical environment, changes in developmental outcomes may affect adult functionality. The purpose of this study is to determine 1) if small increases in diel water temperature affect the development of Arizona tiger salamander (Ambystoma tigrinum nebulosum) larvae, and 2) if this change interacts with exposure to the common environmental thyroid disrupting compound, perchlorate. Larvae between Watson and Russell developmental stages 8-13 were exposed to ammonium perchlorate (AP) at doses of 0, 20 or 200ppb and then raised at either ambient or a 0.9°C elevated above ambient temperature for 81days in outdoor enclosures. During the first 5 treatment weeks, AP treatment induced...

Research paper thumbnail of High ranavirus infection rates at low and extreme temperatures in the tadpoles of Japanese treefrogs (Dryophytes japonicus) that breed in rice paddies in the summer

Journal of Ecology and Environment

Background: Several species of amphibians in agricultural areas are often infected with ranavirus... more 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.

Research paper thumbnail of Prevalence of Ranavirus Infection in Three Anuran Species across South Korea

Viruses

To cope with amphibian die-offs caused by ranavirus, it is important to know the underlying ranav... more To cope with amphibian die-offs caused by ranavirus, it is important to know the underlying ranavirus prevalence in a region. We studied the ranavirus prevalence in tadpoles of two native and one introduced anuran species inhabiting agricultural and surrounding areas at 49 locations across eight provinces of South Korea by applying qPCR. The local ranavirus prevalence and the individual infection rates at infected locations were 32.6% and 16.1%, respectively, for Dryophytes japonicus (Japanese tree frog); 25.6% and 26.1% for Pelophylax nigromaculatus (Black-spotted pond frog); and 30.5% and 50.0% for Lithobates catesbeianus (American bullfrog). The individual infection rate of L. catesbeianus was significantly greater than that of D. japonicus. The individual infection rate of P. nigromaculatus was related to the site-specific precipitation and air temperature. The individual infection rate gradually increased from Gosner development stage 39, and intermittent infection was confirme...

Research paper thumbnail of Distribution and Prediction Modeling of Snake Roadkills in the National Parks of South Korea: Odaesan National Park1a

Korean Journal of Environment and Ecology

In this study, we collected snake roadkill data from 2006 to 2017 and developed a species distrib... more In this study, we collected snake roadkill data from 2006 to 2017 and developed a species distribution model to identify the pattern of snake roadkill and predict the potential hotspot of snake roadkill in the Odaesan National Park of South Korea. During the study period, snake roadkills occurred most frequently on the road, which passes through between forest and stream at an altitude of about 600 m. The modeling result showed that the occurrence probability of snake roadkill was high on a road with a gentle slope at a distance of 25 m from the stream and an altitude of 600 m. The most susceptible regions for snake roadkill in the Odaesan National Park were located on National Route 6, about 2.2 km and 11.7 km away from the southern border of the park, and on Local Road 446, 3.44 km away from the southern border of the park. The results of this study suggest

Research paper thumbnail of Comparison of detective ranavirus with major capsid protein gene from infected frogs (Pelophylax nigromaculatus and Lithobates catesbeianus) in South Korea

Journal of Ecology and Environment

Ranaviruses are a primary cause of amphibian extinctions. More consistent ranavirus-infection rep... more Ranaviruses are a primary cause of amphibian extinctions. More consistent ranavirus-infection reports and genetic characterizations of identified viruses are urgently needed, particularly from Asian countries. The objectives of this study were to obtain the partial major capsid protein (MCP) gene sequences (506 bp) of the ranavirus responsible for infecting frogs in South Korea, as our previous research had confirmed using qPCR, and to evaluate their genetic relationships with other previously reported ranavirus sequences. Three different ranavirus MCP sequences were obtained from Pelophylax nigromaculatus and Lithobates catesbeianus. All six different types of MCP sequence from the ranavirus identified in South Korea to date belonged to the Frog virus 3 (FV3)-like virus group in the genus Ranavirus. To better understand the origin and spread of ranaviruses in South Korea, further infection reports and full genome analyses of the identified ranaviruses are needed.

Research paper thumbnail of Movement Patterns of Juvenile Loggerhead Turtles (Caretta caretta L. 1758) and Green Turtles (Chelonia mydas L. 1758) Hatched in Captivity and Released in the Korean Waters

Animals

With most sea turtle populations declining, activities to conserve their habitat and nesting grou... more With most sea turtle populations declining, activities to conserve their habitat and nesting grounds and restore their populations are being implemented worldwide. To preserve the Northwestern Pacific populations, the National Marine Biodiversity Institute of Korea has been releasing artificially propagated sea turtles, but whether these individuals join the wild population remains unknown. The present study aimed to determine the movement patterns of artificially propagated juvenile loggerhead (Caretta caretta) and green (Chelonia mydas) turtles fitted with satellite transmitters on their carapaces and released in the waters of Jeju or Yeosu, Republic of Korea, between August 2018 and April 2022. Loggerheads traveled northward to the East Sea, whereas green turtles moved west or southwest. Two 36-month-old and two 48-month-old loggerheads moved toward their potential nursery grounds and toward their feeding grounds, respectively. Three green turtles with a curved carapace length (C...

Research paper thumbnail of Additional file 1 of First detection of ranavirus in a wild population of Dybowski's brown frog (Rana dybowskii) in South Korea

Additional file 1 PCR detection of the MCP sequence of ranavirus from the liver tissues of dead R... more Additional file 1 PCR detection of the MCP sequence of ranavirus from the liver tissues of dead Rana dybowskii's adults. The numbers on the bands represent individual frogs. P, positive MCP sequence control of ranavirus from Rana huarenensis tadpoles and N, negative control, which used nuclease-free water instead of extracted DNA in PCR process.

Research paper thumbnail of Additional file 1 of Prediction of present and future distribution of the Schlegel's Japanese gecko (Gekko japonicus) using MaxEnt modeling

Additional file 1: Table S1. Description of the 19 climate variables and their component score co... more Additional file 1: Table S1. Description of the 19 climate variables and their component score coefficient matrix from the principal component analysis (using the RStoolbox package of the statistical program R) of the climate variables. Table S2. The MODIS Land Cover Type Product (MCD12Q1) codes and the labels for each code. Table S3. Raw data of the environmental and climate variables, used in Gekko japonicus distribution modeling at present and future. Figure S1. Response curves of the seven important environmental variables that affect the distribution of suitable habitats of Gekko japonicus: A) Climate PCA1 (temperature seasonality), B) Altitude, C) Distance to the nearest urban and built-up area, D) Slope, E) Climate PCA2 (annual precipitation), F) Land cover type (MCD12Q1), and G) NDVI. Figure S2. Jackknife evaluations of the relative importance of the seven variables affecting the distribution of suitable habitats of Gekko japonicus.

Research paper thumbnail of Multiple Paternity in the Endangered Amur Ratsnake (Elaphe schrenckii)

Russian Journal of Herpetology, 2017

We determined the occurrence of multiple paternity and minimum number of fathers in eight clutche... more We determined the occurrence of multiple paternity and minimum number of fathers in eight clutches of the endangered E. schrenckii in South Korea using offspring obtained from a captive breeding program between 2014 and 2016. By examining five microsatellite loci and comparing the result with the characteristics of mother, egg and offspring we found that seven clutches out of eight (87.5%) showed multiple paternity with mean number of minimum fathers per clutch as 2.3 based on the alleles of fathers, which confirmed sire of offspring. The degree of multiple paternity was negatively correlated with the infertility rate of eggs, but not with any aspects of offspring, suggesting that multiple mating functions to assure the fertilization of eggs. Based on this result, we recommend that each female in the breeding program should be allowed to mate with more than three different males to keep appropriate levels of genetic variability in offspring.

Research paper thumbnail of First detection of ranavirus in a wild population of Dybowski’s brown frog (Rana dybowskii) in South Korea

Journal of Ecology and Environment, 2021

Background Ranavirus is an emerging infectious disease which has been linked to mass mortality ev... more 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 o...

Research paper thumbnail of Predation of the Japanese keelback (Hebius vibakari Boie, 1826) by the Slender racer (Orientocoluber spinalis Peters, 1866)

Journal of Ecology and Environment, 2021

Background The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassifie... more Background The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassified to the new genus Orientocoluber from Hierophis. Ecological knowledge of this species is limited due to its highly mobile behavior. On 17 July 2020, we captured a female O. spinalis on Oeyeon Island, Boryeong-si, Republic of Korea, and collected its feces for a diet analysis. We observed snake scales from the collected feces and subsequently determined the prey species through morphological and molecular methods. Results We initially hypothesized that the extracted fecal sample scales belonged to H. vibakari, due to their thin keel and rhombus shape. We also amplified H. vibakari DNA from the extracted fecal sample using Illumina sequencing methods. Our morphological and molecular results suggest that O. spinalis predates H. vibakari on Oeyeon Island. Conclusion This is the first report of O. spinalis predating another snake species, ophiophagy, and implies that H. vibakari may be a cru...

Research paper thumbnail of Defining Conservation Requirements for the Suweon Treefrog (Dryophytes suweonensis) Using Species Distribution Models

Diversity, 2021

Numerous amphibian species are declining because of habitat loss and fragmentation due to urbaniz... more Numerous amphibian species are declining because of habitat loss and fragmentation due to urbanization of landscapes and the construction of roads. This is a mounting threat to species restricted to habitats close to urban areas, such as agricultural wetlands in North East Asia. The Suweon treefrog (Dryophytes suweonensis) falls into the list of species threatened with habitat loss and most populations are under threat of extirpation. Over the last decades, sub-populations have become increasingly disconnected and specifically the density of paved roads has increased around the only site connecting northern and southern Seoul populations. We surveyed this locality in Hojobeol, Siheung, Republic of Korea in 2012, 2015 and 2019 to first confirm the decline in the number of sites where D. suweonensis was present. The second objective was to analyze the habitat characteristics and determine the remaining suitable habitat for D. suweonensis through a species distribution model following ...

Research paper thumbnail of Preferred Feeding Sites and Prey of the Adult Gold-spotted Pond Frog, Rana plancyi chosenica

Journal of Ecology and Environment, 2007

Research paper thumbnail of Genetic diversity and inferred dispersal history of the Schlegel’s Japanese Gecko (Gekko japonicus) in Northeast Asia based on population genetic analyses and paleo-species distribution modelling

Mitochondrial DNA Part A, 2020

To understand the genetic diversity and dispersal history of Schlegel's Japanese gecko (Gekko jap... more To understand the genetic diversity and dispersal history of Schlegel's Japanese gecko (Gekko japonicus), we performed genetic analyses and paleo-species distributional modelling. For the genetic analysis, we analyzed mitochondrial DNA (mtDNA) (cytochrome b [Cytb] and NADH dehydrogenase 2 [ND2]) and seven microsatellite loci of 353 individuals from 11 populations (2 east coast China, 4 west and central coast Japan and 5 Korea). For the paleo-species distribution modelling, we used 432 occurrence data points (125 China, 291 Japan and 16 Korea) over the Pleistocene and Holocene. China is inferred to be the source population, which had higher genetic diversity (mtDNA) and more private alleles (mtDNA) compared to Japanese and Korean populations. Differences between the three counties were very small in the mtDNA haplotype network despite some genetic structure among the three countries. Microsatellite analysis inferred that genetic exchange has actively occurred among the Chinese, Japanese and Korean populations. Suitable habitats in Japan should have been plentiful by the mid-Holocene, but have only recently become available in Korea. These results suggest that dispersal of G. japonicus occurred after the Holocene warming from the east coast of China to the west and central coasts of Japan and Korea, and gene flow is actively occurring among the three countries.

Research paper thumbnail of Analysis of the Correct and Incorrect Reports on the Observation and Capture of Sea Snakes in the Coasts of South Korea

Korean Journal of Environment and Ecology, 2017