Polyculture of male nile tilapia and giant prawn (Macrobrachium rosenbergii) reared intensively in concrete tanks

anglais. Assuming that the optimal stocking densities of male nile tilapia (50 g) and giant prawn (1,5 g) in 2 x 5 m concrete tanks were 12 fish/square m and 20 prawn/square m or 600 g/square m and 30 g/square m respectively combinations in number of individuals of 100 percent, 75 percent, 50 percent and 25 percent were evaluated. Artificial feed for the nile tilapia were given at 2 percent of body weight per day during daytime while the prawn were fed at 5 percent at night. After 20 weeks the results were not significant. The growth rates of nile tilapia was 1.4 percent/fish/day or 1.36 g/fish/day; giant prawn 1.5 percent/prawn/day or 0.6 g/prawn/day. The mortality rates of male tilapia was 5 percent and that of the prawn was 34 percent. The food conversion ratio by nile tilapia in 20 weeks was 1.69 and that of the prawn was 3.84. Male nile tilapia in 20 weeks was 1.69 and that of the prawn was 3.84. Male nile tilapia in 20 weeks grew from 50 g to 241 g and the giant prawn from 1.5 g to 6.5 g

indonésien. Dengan asumsi padat penebaran optimal bagi ikan nila jantan (50 g) dan udang galah (1,5 g) dalam bak beton 2x5 m masing-masing 12 ekor/m2 dan 20 ekor/m2 atau 600 g/m2 dan 30 g/m2 disusun komposisi jumlah individu penebaran 100 persen, 75 persen, 50 persen dan 25 persen. Pakan untuk nila sejumlah 2 persen perhari diberikan siang hari untuk udang galah 5 persen perhari diberikan malam hari. Pertumbuhan berat diamati setiap 2 minggu secara total bagi nila dan contoh 5 persen bagi udang galah. Setelah masa pemeliharaan 20 minggu ternyata perbedaan antar perlakuan tidak nyata secara statistik. Kecepatan tumbuh ikan nila rata-rata 1,4 persen/ekor/hari atau 1.36 g/ekor/hari; udang galah 1,5 persen/ekor/hari. Kematian udang galah selama 20 minggu rata-rata 34 persen sedang kematian ikan nila rata-rata 5 persen yang sebagian besar sebagai akibat penanganan waktu pengamatan. Konversi pakan bagi ikan nila dan udang galah selama 20 minggu masing-masing rata-rata 1,69 dan 3,84. Berat individu ikan nila (50g) dan udang galah (1,5g) sesudah 20 minggu masing-masing mencapai rata-rata 241 g dan 6,5 g