09-The(0105)-컬러.103448.pdf199.5KB

INTRODUCTION

 Testudines are most successfully evolved group (Ernst and Barbour 1989; Gaffney 1990), and, internationally, they consist of 14 families, 319 species and 146 subspecies(Bickham et al. 2007). The Korean peninsula contains both aboriginal turtles, Chinemys reevesii in Geoemydidae, Pelodiscus sinensis in Trionychidae, (Kang and Yoon 1975), and foreign turtles that adapted to Korean environment are reported (NIBR 2012); Trachemys scripta elegans, T. s. scripta, Pseudemys rubriventris and Ocadia sinensis. Chinemys reevesii are protected as an endangered species level II and a natural monument. The freshwater turtle is widely distributed throughout Korea, China, Japan and Taiwan, including South East Asia (Ota 1991; Szyndlar 1991; Iverson 1992). It lives in small lakes, ponds and streams in Korea except in Jeju-do (Song 2007). According to recent studies, C. reevesii was discovered only in one-tenth of places investigated and its population size was extremely small; thus, preservation is urgent (NIBR 2011). P. sinensis has been found in the Amur River and Ussuri River in Southeast Siberia, Korean peninsula, Hainan, South Central China and Vietnam (Iverson 1992; Ernst et al. 2000), and P. sinensis has been discovered in similar places as C. reevesii (Song 2007).

 Although national studies on endangered turtle groups are underway, only a small number of academic study on Korean freshwater turtles have been conducted, including mitochondrial gene analysis of P. sinensis (Jung et al. 2006), skin diseases(Syasina et al. 2006), distribution, environmental features and feeding behavior in Seomjin-gang and Nam-gang areas (Lee and Park 2010). Freshwater turtles can be easily surveyed over the country in streams, ponds, swamps and rice fields. However, according to the studies by the Ministry of Environment, the population of native turtles has been considerably decreasing since 1986. This decrease was believed to be caused by water pollution, habitat destruction and overhunting. The reckless release of foreign turtles without ecological data and studies has also been one cause for the decrease in native turtles. Despite this decrease in native turtles, there have been no studies on the distribution of freshwater turtles in the Korea peninsula. In addition, the old scientific name for C. reevesii and P. sinensis are still being used in Korea, even after the name was revised through previous systematic studies. Especially, in the case of P. sinensis, the scientific name was written wrong because of confusion between the new species and adapted species (Fritz et al. 2010).

 Turtle traps and field-scopes were placed in rivers, reservoirs and ponds were for this field study. Previous studies were also reviewed to confirm the distribution of native turtles in Korea. In addition, the scientific name of the freshwater turtles was appropriately changed. Based on the findings of this study, the state of inhabitant and the taxonomic position of the turtles should be considered in the future.

MATERIALS AND METHODS

1. Survey area

 The survey was scrutinized focusing on the water system that the freshwater turtles were reported by literature and news releases. Additionally, we selected and surveyed ponds or reservoirs near the water system.

2. Observation survey

 Turtles feeding or sunning on the surface of water, trees, rocks and artificial structures were observed between May 2010 and November 2011 during the day time. Each of the researchers were equipped with a radio and searched for the animals on each side of reservoir using binoculars and field scopes (ATM 80 HD, Swarovski).

3. Capture survey

 A net (3.5 cm×3.5 cm) and metal frame (70 cm×70 cm ×150 cm) were used to collect turtles and 20~30 g of pork was fixed by cable in the trap as bait. Traps were located to the edge of the water and put it into the sand or mud. If the bottom of the water consisted of stone, the trap was fixed on the tree by ties. In the summer, the traps were installed in an unusual pattern during the night and collected the next morning, due to the high temperature. At least two and up to 10 traps were set up at each location.

RESULTS AND DISCUSSION

 Chinemys reevesii and Pelodiscus sp. were discovered in 16 and 11 locations, respectively (Table 1). Although Pelodiscussp. was found in ten areas, it was not clear between two soft-shell turtles that were reported in Korea and morphologically very similar. Two soft-shell turtles were shown to inhabit Korea and they are morphologically very similar. The taxonomic position of C. reevesii remains controversially. The turtle was named Emys reevesii by Gray (1831). In the late twentieth century, the name was revised and the species was placed in the genus Chinemys by Smith (Ernst and Barbour 1989; Iverson 1992; Zhao and Adler 1993). However, when cladistic analysis based on morphological data was used, it was classified as Geoemydidae (Hirayama 1984; Gaffney and Meylan 1988; Yasukawa et al. 2001). Using morphology and molecular biology analysis, Shaffer et al. (1997) found that the genus Chinemys was close to the genus Heosemys. In another study, the genus Chinemys and genus Ocadia were included in genus Mauremys (Wu et al. 1998; McCord et al. 2000; Honda et al. 2002; Barth et al. 2004; Spinks et al. 2004; Feldman and Parham 2004). In contrast, Parham et al. (2001) asserted that C. reevesii and C. nigricans were distant from the genus Mauremys, which was based on molecular data. In addition, Spinks et al. (2004) suggested that C. reevesii and other species that had been classified to genus Chinemys and genus Ocadia for a long time be subordinated in genus Mauremys. Thus, based on the study by Spink et al. (2004), the turtle in the Korean peninsula was classified as M. reevesii.

Table. 1. The state of freshwater turtles observing site

 Soft-shell turtles in Korea were first reported by Slevin (1925) as Amyda maackii. He collected 16 turtles in Gongju, Chungcheongnam-do. The black line on the interocular and temporal of the Korean turtle was found to be thicker than the line on the Chinese turtle and it contained many more yellow spots on its back. In addition, Slevin (1925) reported that the only difference between the Korean turtle and Chinese turtle was the external color. Dakashima (1935) classified the turtle in Korea as A. maackii and recorded that it moved into Japan. He also reported that A. sinensis was imported from Taiwan to Okinawa, Japan. However, Pope (1935) classified the three species, schlegelii, sinensis and maackii in genus Amyda, as one species, A. sinensis, and reclassified the soft-shell turtles in the Korean peninsula as A. sinensis. Until the late of 1980s, there were no additional studies on soft-shell turtles and A. sinensis was thought to be the only species in Korea. On the other side, Cho (1949) did not accept Pope (1935)’s view and classified the turtle as A. maackii. Shannon (1956) reported that turtles collected in Hantan River and Gongju in South Korea and Pyongyang in North Korea were A. sinensis. He initially wanted to report that the turtle was A. maackii and stated that it was distributed in Korea and a branch of Southern Amur River; however he followed Pope (1935)’s opinion and recorded it as A. sinensis. Amyda maackii and A. sinensis have been named the soft-shell turtles found in South Korea. After changing the genus from Amyda to Trionyx, each of Kang and Yoon (1975) and Paik (1989, 1990) reported it as A. sinensis and Trionyx maackii. In the late 1990s, most documents used P. sinensis. Moreover, in the case of North Korea, Won (1971) and Kim and Han (2009) concluded that A. maackii was a synonym of Trionyx sinensis and accepted the scientific name, T. sinensis. However, Chkhikvadze (1987) reclassified the turtle that lives in Northeast China and adjacent region between Korea and Russia to T. maaki(=maackii). Also, the genus name of the Korean soft shelled turtle was changed from Trionyx to Pelodiscus once more by several taxonomic studies. Despite the fact that Jung et al. (2006) classified it as P. sinensis based on mitochondrial analysis using a male turtle from soft-shell turtle farm in Deagu, Fritz et al. (2010) reanalyzed both Jung’s result and the group of turtles in East Asia and clarified the turtle in Jung’s study as P. maackii. Stuckas and Fritz (2011) reported that each P. maackii and P. sinensis were independent species, because the genes of the two species were different. Based on biological distributions, P. maackii inhabits the Amur River, Far East Russia, Northeast China and Korea peninsula, and the Type locality of P. sinensis is Macao located adjacent to Southern China. Therefore, P. maackii is a Korean native turtle and P. sinensis is not.

 Pelodiscus sinensis has been traded in Asia region since B.C., and was exported to the world from China in the late 1900s. Japan imported this species in 1970s, so we estimated that the turtle actually entered Korea between the 1970s and 1980s. P. maackii and P. sinensis are now frequently found in the wild in Korea. According to Slevin (1925) and Pope (1935), there are no skeletal differences between these two turtle species and they only diverge in color. The table for distinguishing the two turtles was prepared with previous data (Chkhikvadze 1987; Yang et al. 2011) and individuals observed in the wild (Table 2). In conclusion, we suggest that M. reevesii is the appropriate scientific name for Reeve’s turtle and P. maackii is the correct scientific name for Korean soft-shell turtle.

Table 2. Comparison table between Korean soft-shell turtle and Chinese soft-shell turtle

ACKNOWLEDGEMNET

 We thank Dr. Han Sang-Hoon and his contribution. This study was supported by NIBR (National institute of Biological Resources).