Bubu dasar (bottom fish pots) merupakan alat tangkap yang dominan terdapat di pulau Bunyu Kabupaten Bulungan Kalimantan Utara, termasuk kelompok “trap fishing gear” atau alat tangkap perangkap. Ikan kerapu dan ikan kakap merah adalah hasil tangkapan utama bubu dasar, merupakan ikan demersal yang hidup di area atas dasar perairan. Penelitian dilakukan untuk mengetahui karakter morfologi (panjang dan berat) dan aspek bio-reproduksi (Tingkat Kematangan Gonad / TKG, Indeks Kematangan Gonad / IKG, dan fekunditas) ikan hasil tangkapan utama bubu dasar. Metode riset menggunakan pendekatan observasi, selama 3 bulan dengan pengambilan sampel 12 kali trip. Hasil riset periode Mei - Juli menunjukkan kisaran ukuran panjang 27.0 – 56.0 cm (kakap jantan); 24.9 – 55.0 (kakap betina); 33.0 – 55.5 cm (kerapu jantan); 29.0 – 57.5 cm (kerapu betina). Kisaran berat sampel 340.5 – 2392.0 gram (kakap jantan); 416.8 – 3121.1 gram (kakap betina); 497.8 – 2580.1 gram (kerapu jantan; 300.0 – 3494.0 gram (kerapu betina). Jumlah individu terbanyak sampel kakap dan kerapu pada TKG I. Kematangan gonad tertinggi pada TKG III (kakap dan kerapu jantan) dan TKG IV (kakap dan kerapu betina). Nilai fekunditas pada sampel menunjukkan jumlah terkecil 650 butir (kakap) dan 600 butir (kerapu). Nilai fekunditas terbesar 6.903 butir (kakap) dan 13.813 butir (kerapu).
Kata Kunci: Bio-Reproduksi; Bubu; Morfologi Ikan Kerapu; Ikan Kakap Merah

Bottom fish (Bottom Fish Pots) are the dominant fishing gear fond on the Bunyu Island, Bulungan regrency, North Kalimantan, including the fishing trap group gear or trap fishing gear. Grouper and Rad Snapper are the result the main catch of bottom trap is demersal fish that live in the bottom area water. The study was conducted to determain the morphological characteristics (length and weigth) and bio – reproductive ( Gonadal Maturity Level / TKG, Index Gonad Maturity / IKG, and Fecubdity) the main catch of bottom traps. The set method uses and observational approach, for 3 months by taking sample 12 trip. The research results for the May – July period show a long range of size 27.0 – 56.0 cm (male snapper), 24.9 – 55.0 cm (female snapper), 33.0 – 55.5 cm (male grouper), 29.0 – 57.5 cm (female grouper). Sample weight range 340.5 – 2392.0 grams (male snapper), 416.8 – 3121.1 grams (female snapper), 497.8 – 2580.1 grams (male grouper), 300.0 – 3494.0 grams (female grouper). The langest number of individuals in snapper sample and grouper in TKG I, the highest gonad in TKG III (snapper and grouper male) and TKG IV (snapper and grouper female). Fekundity value in the sample showed the smallest number of 650 eggs (snapper) and 600 eggs (grouper). Fecundity value the biggest was 6.903 eggs (snapper) and 13.813 eggs (grouper). Keywords: Bio–Reproductive; pots; Grouper Morphology, Red snapper