A Chromosomal Study on the Genus Cobitis (Pisces : Cobitidae) in the Southern Part of Korea

한국 남부지방에 서식하는 기름종개속(Cobitis) 어류의 핵형 비교

The Chromosomes of five cobitid fishes, Cobitis taenia taenia, C. taenia lutheri, C. taenia striata, C. longicorpus and C. koreensis were studied. The karyotypic studies were based on the observations from the flame-drying preparations. The results obtained such as the number of somatic chromosomes, the type of chromosomes according to the centromeric loci and the number of chromosomal arm(AN) were as follows: C. longicorpus, 2n=50, 12m-8sm-30a, AN=70; C. koreensis, 2n=50, 10m-12sm-28a, AN=72; C. taenia taenia, 2n=48, 14m-4sm-30a, AN=66: C. taenia lutheri, 2n=50, 10m-6sm-34a, AN=66; and C. taenia striata, 2n=50, 10m-6sm-34a, AN=66. Peculiarly, in the case of C. taenia lutheri the chromosome number of somatic diploid was found to be 48-51, however, the number of chromosomal arm was 66, irrespective of the difference in the numbers of each somatic genome. It was confirmed there exists the Robertsonian event, one of the chromosomal polymorphism in C.t. lutheri. It was remarked taxonomically that the karyotype of C. taenia taenia of Korea having 48 diploid chromosomes was not identical with that of Europe and Japan with 50 chromosomes. Based on the karyotype analysis the Korean cobitid fishes can be classified roughly into three species groups according to arm numbers and diploid numbers; 1) C. taenia taenia, C. taenia lutheri, C. taenia striata 2) C. koreensis, C. longicor pus, C. rotundicaudata and 3) C. granoei.

우리나라 남부지방에 서식하는 기름종개속 어류의 5종 및 아종, Cobitis taenia taenia, C.taenia lutheri, C.taenia striata, C.koreensis, C.longicorpus의 핵형 분석 결과, 2n의 수, karyotype form (metacentric-submeta centric-acrocentric chromosome), AN(arm number)은 다음과 같다. C. longicorpus, 2n=50, 12m-8sm-30a, AN=70; C. koreensis, 2n=50, 10m-l2sm-28a, AN=72; C. taenia taenia, 2n=48,14m-4sm-30a, AN=66; C. taenia striata, 2n=50,10m-6sm-34a, AN=66; C. taenia lutheri, 2n=50,10m-6sm-34a, AN=66. 이 가운데 C.t.lutheri는 2n=48, 49 및 51도 높은 빈도로 나타나고, 각각의 AN이 66인 점으로 미루어 Robertsonian 염색체 다형현상을 나타내었다. 그리고 본 조사에서 특히 주목되는 것은 C.taenia taenia의 핵형은 2n=48로서 종전의 결과와는 아주 다르고, 또 본 조사집단의 반문등 형태적 특징에 있어서도 유럽산 C.t.taenia와 구분되기때문에 이 개체군은 분류학적으로 별종이 된다고 사료된다. 그리고 본 조사결과 각 종의 집단이나 개체내에서는 현저한 변이는 없었으나, diploid number와 arm number를 이용하여 유연관계를 본 바 다음 3가지의species group으로 나눌 수 있었다. 1) C. taenia taenia, C. taenia lutheri 및 C. taenia striata 2) C. koreensis, C. longicorpus 및 C. rotundicaudata 3) C. granoei