Earticle

Although frogs are known to be important hosts for leeches, very few related studies have been conducted in South Korea. To investigate ecological characteristics of leech ectoparasitism on mountain frogs (Rana dybowskii and Rana huanrenensis) and to test if a leech infection rate (number of leeches per frog) is affected by temperature fluctuation in water pools, we have investigated 46 water pools in four different valleys within Odaesan National Park in the spring of 2010. According to morphological characteristics, we classified the collected leeches into Parabdella quadrioculata or Torix tagoi. Rana dybowskii (92%, 86 out of 94 frogs) was more infected by leeches than R. huanrenensis (88%, 77 out of 89 frogs) was. The sex, amplexus status, and condition factor (body mass/ snout-vent length) of frogs did not affect the infection rate. Among eight environmental factors, pH and DO in water pools, shortest distance to mountain from the pools, and size of the pools negatively affected the leech infection rate. We did not find any evidence that temperature fluctuation in water pools affects the leech infection rate. The leech infection rate was significantly different among valleys and specially the rate was the lowest in Gujiri valley. Considering that mountain frogs were greatly infected by leeches, leeches may increase the mortality of larval and adult frogs in wild.

본 연구는 한국에 서식하는 유린목의 분류학적 위치를 명확히 하기 위하여, 기존에 소개된 국내·외 연구결과를 바탕으로 파충류 종 목록을 재정리 하였다. 연구결과, 우리나라에 서식 하는 유린목 파충류는 총 6과 17속 25종이었으며, 남한에 서식하는 종은 21종, 북한에 서식 하는 종은 24종 으로 파악되었다. 또한 환경부(2012)의 결과와 비교할 때, 무자치속(Oocatochus)과 줄꼬리뱀속 (Orthriophis)이 추가되었으며, 바다뱀과(Hydro- phiidae)가 코브라과(Elapidae)로, 장수도마뱀속(Eu- meces→Plestiodon)과 실뱀속(Coluber→Hierophis) 의 속명이 변경되었다. 향후, 국내·외 연구결과를 지속적으로 파악하여 한국산 파충류의 종 목록을 갱신할 필요가 있다고 판단된다.

We readjusted the list of Squamata, one of reptile groups distributed in Korea, based on the results of previous studies to define the taxonomic position. In consequence of our research, 6 familis, 17 genus and 25 species of Squamata are confirmed in Korea, 21 species and 24 species in South Korea and North Korea respectively. Comparing with the result of Environment Minister of Korea (2013), two genus, Oocatochus and Orthriophis, was added, and the four changes of generic names were occurred to confirmed species; Hydrophiidae to Elapidae, Eumeces to Plestiodon, and Coluber to Hierophis. Henceforth, we suggest that the list of reptiles distributed in Korea is needed to be renew continuedly through the studies with inside and outside of the country.

본 연구는 멸종위기종인 수원청개구리의 분포 및 서식지 특성을 조사하기 위하여 2012년 5월부터 7월까지 전국을 대상으로 수행되었다. 연구결과 43지점에서 총 265마리의 수원청개구리를 확인 하였다. 서식지 특성을 분석한 결과, 모든 지점은 강이나 수로를 끼고 있는 대규모 농경지이었으며, 평균고도, 산과의 거리, 강과의 거리, 민가와의 거리 는 각각 18.0 m, 1137.4 m, 144.4 m, 295.8 m로 확인되었다. 따라서 멸종위기종인 수원청개구리를 효과적으로 보호하기 위해서는 저지대 농경지를 우선 보호해야 하며, 이 종의 기초생태 연구가 추가 적으로 수행되어야 할 것으로 보인다.

In this study, we investigated the distribution and habitat characteristics of the endangered Suweon-tree frog (Hyla suweonensis) in the south part of Korean peninsula between May and June 2012. Upon investigation, we discovered 265 Suweon-tree frogs at 43 locations. In the analyses of habitat characteristics, all habitats were located in the farmland including irrigation canal. A mean altitude, distance from the mountain, distance from the river and distance from the village of habitats were 18.0 m, 1137.4 m, 144.4 m and 295.8 m, respectively. Therefore, to conserve habitats for this endangered species, we need to mainly protect the low-lying farmlands where their main habitats are placed. Also, further basic ecological studies should be done in near future to preserve this endangered Suweon-tree frog species.

우리는 2012년 5월부터 8월에 걸쳐 경기도 파주시 탄현면과 충청남도 아산시 둔포면에서 멸종 위기종인 수원청개구리의 번식기를 확인하였고, 이후 2013년 이 종의 번식기 중 5월과 6월에 동 지점 에서 울음소리를 통해 번식행동의 일주기를 연구 하였다. 연구기간 동안 자매종인 청개구리의 번식 행동생태를 같이 연구하여 두 종간의 차이를 확인 하였다. 결과로, 수원청개구리의 번식기는 5월 18일 부터 7월 30일로 확인되었고, 번식행동의 일주기 연구결과 수컷 수원청개구리는 약 4시부터 울음을 시작하여 평균 11시간 동안 번식울음을 유지하였다. 이는 청개구리에 비해 약 4시간 가량 빠르게 시작 하며 비슷하게 종료하는 것이었다.

In 2012, we visited Tanhyeon-myeon, Paju-si, Gyeonggi-do and Dunpo-myeon, Asan-si, Chungcheongnam-do from May to August to determine the breeding season of the endangered Suweon-tree frog (Hyla suweonensis). After determining the season, we studied the daily patterns of advertisement call of the species at the same study sites from May to June in 2013. During surveys, we investigated the breeding patterns of Japanese-tree frog (H. japonica) the sibling species of H. suweonensis. In results, Suweon-tree frog has breeding season from May 18 to 30 July. Upon investigation about the daily patterns of mating behavior male Suweon-tree frogs initialed advertisement calls at 4 pm and the calls were maintained about 11 hours. We identified that the Suweon-tree frog started advertisement call about four hours earlier than Japanese-tree frog did.

There are two tree frog species of genus Hyla in Korea: H. japonica and H. suweonensis. Hyla suweonensis, is an endemic species and is designated as an endangered species I in 2012 by the Korean Ministry of Environment. Hyla suweonensis populations are decreasing rapidly due to habitat destruction and human activities. To maintain the biodiversity in South Korea, a strategic conservation plan is urgently needed. The purposes of this study were to investigate the genetic diversity of H. suweonensis and to provide basal genetic information, using mitochondrial cytochrome b (cyt b) gene and cytochrome oxidase subunit I (COI) gene analyses. Also, we examined intraspecific genetic diversity of H. japonica and genetic divergence between H. suweonensis and H. japonica. We used samples from South and North Korea, Russia, and Japan. Partial sequences of cyt b (926 bp) and COI (534 bp) genes were obtained from 68 H. suweonensis and 271 H. japonica individuals. Hyla suweonensis was also identified in North Korea using molecular data. Most populations of two species had unique haplotypes with few nucleotide substitutions in both genes. Mean nucleotide diversity (π) of H. suweonensis was relatively lower than that of H. japonica for both genes. The average sequence divergence of combined cyt b and COI genes among Korean H. suweonensis and H. japonica populations were 0.002 and 0.009, respectively. The mean sequence divergence between H. suweonensis and H. japonica was 0.137, indicating genetic differentiation occured approximately 7 million years ago, based on 2% divergence rate per million year.