한국산 기름종개 Cobitis taenia Linne의 연구 3. 횡반B${\cdot}$C형의 형태와 분포

A STUDY OF KOREAN SPINOUS LOACHES(Cobitis taenia Linne) 3. On the Morphology and Distribution of the Crossband B-type and C-type

여러가지 반문형을 가진 기름종개는 우리나라의 어디에나 널리 분포하지만 횡반B형과횡반 C형은 영산강과 섬진강에서만 서식하고 있어 주목된다. 이 2형은 반문과 지리적 분포상 차이를 보이면서도 이들의 체장분포, 아가미뚜껑뒤의 친한 흑갈색의 반점, 골질반의 구조, 비늘의 형태는 동일하다. 그러나 반문, 2차성징, 체장분포 및 비늘의 형태상 특징은 본속 기지종과는 분명희 구별된다. 이것은 지리적 격리에 의하여 생긴 고유한 형태로서 원래 동일종 이었던 것이 오랜 세월이 지남에 따라 한때 연결되었으리라고 추측되는 영산강과 섬진강이 각각 독립되므로 양개체군간에 교배가 불가능하기 때문에 반문의 분화가 생긴 것으로 본다.

Spinous loaches widely distributed in Korea, are of many color pattern types, but interestingly the crossband B and C-types of these coaches are collected only in the two rivers, the Yeongsan River and the Seomjin River, flowing through the south-western part of Korea. These two types have not only different color pattern, but also different geographical distribution: the B-type is found in the Yeongsan River and the C-typs, in the Seomjin River. But the both types have four common distinctive features, which easily distinguish them from other already known species of this genus: the B and C-types have the similar total length distribution, the same structure of lamina circularis and scales, and the black spots at the back of their opercula. These peculiarities may be explained by studing the history of these two rivers. The author considers that they are once rivers of the same origin located around the Noryeong and the Sobaeg Mountains, and then were eventually separated from each other as the water level or the crust of Korea peninsula changed. Thus, these two types, B and C, of spinous loaches should have been the same species living in the same river, but in the course of time, these two types have taken different color patterns since the separation of two rivers thus making them impossible to cross between these two populations.