Geographic Variation and Interspecific Hybridization between Two Species of the Genus Agkistrodon (Crotalidae) in Korea

한국산 살모사속(뱀과) 2종의 지리적 변이 및 종간 잡종

Genetic and morphometric comparison between two species of the genus Agkistrodon were performed to estimate the degree of genic variation and to clarify the taxonomic status of Cheju population, a suspected hybrid form between A. blomhoffii brevicaudus and A u ussuriensis. A sum of 147 specimens representing six populations of A.b. brevicaudus and two populations of A ussuriensis was used in this study. Out of the 21 loci examined, 5 loci (Adh, Ldh-2, Mdh-2, Mpi, Pgi) were monomorphic with identical mobility in both species. O Other Sioci (Aco, Gp, Fum, [po and Xdh in A b. brevicaudus; Est, Got-l, Gp, Mdh-l and 6Pgd in A ussuriensis) were highly poplymorphic. The degree of genic variation of Ab. b brevicaudus and A ussuriensis was A=1.SS, P=42.1%, HD=0.096, HG=O.l1S, and A= 1.4S, P = 31.6%, HD=0.117, HG =0.121, repectively. These values are twofold higher t than those of other reptilian species reported (Selander, 1976) including Korean species of Rhabdophis tigrina and Elaphe dione (Paik and Yang, 1986, 1987). The average values of t the genetic similarities among six populations of A b. brevicaudus and two populations of A ussuriensis were S=0.919 and S=0.962, respectively, whereas the value between species was S = 0.662. Presumed divergent time estimate (Nei, 1975) of these two species was about 1 1.8 million years ago. The analysis of the geographic variations of various morphological c characters was based on Gloyd’s criteria (Gloyd, 1972). Coloration of tongue and tail tip, t the number of ventral scales, and the number of subcaudal scales are good diagnostic c characters to identify these two species. The pattern of cross band is, however, highly variable within and between populations of both species. No hybrid was detected and the s suspected hybrid form of Cheju population falls within the range of A. ussuriensis in the g genetic and morphometric analyses.

한국산 살모사속 (Agkistrodom) 2종의 유전적, 형태적 및 종간잡종 형성 유.무를 구명하기 위하여 남한의 7개 지역에서 147개체를 채집하여 전기영동 및 형태형질 분석을 실시한 결과는 다음과 같다. 1. 15개의 성소 및 단백질에서 19개의 유전자를 검출하여 유전적 변이를 조사한 바 5개 유전자(26.3%)는 종간 및 집단간에 전혀 차이가 없었고 나머지 14개의 유전자중 4개 유전자는 매우 높은 률의 유전적 변이를 나타내었다. 2. 각 집단의 유전적 변이정도를 산출한 결과 A. b. brevicaudus는 평균 A= 1.55, P=42.1%, HD=0.096 및 HG=0.1l5였고 A .ussuriensis는 A= 1.45, P=31.6%, HD=0.1l7 및 HG=0.122로서 타 파충류에 비하여 높은 유전적 변이를 나타냈으며 이는 이들 종의 집단이 크고 안정된 상태에 있다고 사료된다. 3. 형태적으로 2종의 중간형으로 여겨졌던 제주집단은 강릉집단의 A .ussuriensis와 동일종으로 확인되었으며 종간 잡종은 전혀 찾아볼 수 없었다. 4. 2종간의 유전적 근록치는 S=0.662로서 이들은 약 180만년전에 분화되었으리라 추산된다.