In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species’ ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M. yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density.

서 론
재료 및 방 법
    1. 조사대상지 및 유기물·어류 시료 채집
    2. 안정동위원소 분석
    3. 안정동위원소비 값의 활용
결 과
    1. 먹이망 구조 및 분류군별 탄소·질소 안정동위원소비
    2. 먹이원 기여율 및 영양단계
    3. 생태지위면적
고 찰
적 요
REFERENCES

• 이대희(경희대학교 환경응용과학과) | Dae-Hee Lee (Department of Environmental Science and Engineering, Kyung Hee University, Yongin 17104, Republic of Korea)
• 오혜지(경희대학교 환경응용과학과) | Hye-Ji Oh (Department of Environmental Science and Engineering, Kyung Hee University, Yongin 17104, Republic of Korea)
• 최예림(경희대학교 환경응용과학과) | Yerim Choi (Department of Environmental Science and Engineering, Kyung Hee University, Yongin 17104, Republic of Korea)
• 홍근혁(경희대학교 환경응용과학과) | Geun-Hyeok Hong (Department of Environmental Science and Engineering, Kyung Hee University, Yongin 17104, Republic of Korea)
• 백인혁(국립생태원 멸종위기종복원센터) | InHyuck Baek (Research Center for Endangered Species, National Institute of Ecology, Yeongyang 36531, Republic of Korea)
• 김근식(국립생태원 멸종위기종복원센터) | Keun-Sik Kim (Research Center for Endangered Species, National Institute of Ecology, Yeongyang 36531, Republic of Korea)
• 장광현(경희대학교 환경응용과학과) | Kwang-Hyeon Chang (Department of Environmental Science and Engineering, Kyung Hee University, Yongin 17104, Republic of Korea) Corresponding author
• 윤주덕(국립생태원 멸종위기종복원센터) | Ju-Duk Yoon (Research Center for Endangered Species, National Institute of Ecology, Yeongyang 36531, Republic of Korea) Corresponding author