Keanekaragaman adalah jumlah total spesies dalam suatu area sebagai jumlah spesies antar jumlah total individu dari spesies yang ada di dalam suatu komunitas. Tujuan penelitian adalah untuk mengidentifikasi dan mengetahui keanekaragaman serta kelimpahan ikan asli Desa Atap, Kecamatan Sembakung, Kabupaten Nunukan. Pengumpulan sampel dilakukan di Sembakung Desa Atap, Kabupaten Nunukan, Kalimantan Utara pada bulan Desember – Februari 2022. Metode yang digunakan dalam penelitian ini yaitu metode deskriptif kuantitatif. Sampel ikan dikumpulkan dengan menggunakan alat tangkap tugu, jala, Gill net dan bubu. Ikan yang tertangkap diidentifikasi secara morfologi dan dilihat keanekaragamanya. Keanekaragaman ikan yang didapatkan sebanyak 3595 ekor dan didistribusikan kedalam 2 filum, 2 kelas, 7 ordo, 15 famili dan 21 genus. Kelimpahan hasil tangkapan yang tertinggi terdapat 3 genus dengan persentase yaitu, Cryptopterus 64.09%, Barbodes 11.32%, Labiobarbus 10.74%. Sebaliknya untuk jenis dengan kelimpahan yang terendah terdapat 3 genus dengan persentase yaitu, Nematabramis, Trichogaster, Macrognathus yaitu masing-masing 0.03%.
Kata Kunci: Ikan Asli, Keanekaragaman, Kelimpahan Relatif

Diversity is the total number of species in an area as the number of species among the total number of individuals of the species in a community. The objective of the present study was to identify and determine the diversity and abundance of native fish in Atap Village, Sembakung District, Nunukan Regency. The samples were collected in Atap Village, Sembakung District, Nunukan Regency,North Kalimantan from December 2021 to February 2022. This study was quantitative descriptive research. The fish samples were collected using various fishing gears, namely: tugu, nets, gill nets, and bubu traps. The fish caught were then identified morphologically and observed for their diversity. In terms of the fish diversity, it was obtained 3,595 individuals and distributed into 2 phyla, 2 classes, 7 orders, 15 families, and 21 genera. In terms of fish abundance, it was found the highest abundance of catches was in 3 genera with a percentage of Cryptopterus at 64.09%, Barbodes at 11.32%, and Labiobarbus at 10.74%. The species with the lowest abundance were in 3 genera with a percentage of Nematabramis, Trichogaster, and Macrognathus at 0.03% respectively. Keywords: Native Fish, Diversity, Relative Abundance