PEMIJAHAN ALAMI ARWANA SILVER (Osteoglossum bicirrhosum) DALAM BAK TERKONTROL

Abstract

Ikan arwana silver (Osteoglossum bicirrhosum) adalah ikan hias introduksi berasal dari Brazil yang sudah menjadi ikan hias potensial. Tujuan penelitian ini ialah untuk mengetahui teknik pemijahan secara alami ikan arwana silver dalam bak terkontrol. Induk arwana jantan dan betina yang sudah diberi penanda (tagging) sebanyak 12 ekor diadaptasikan dalam bak beton (3 m x 2 m x 1 m) yang diletakkan di dalam ruangan yang dilengkapi dengan instalasi aerasi. Pakan diberikan berupa percil (50 g) dan ikan selar (360 g) dua hari sekali. Setelah 10 bulan ikan arwana mencapai panjang berkisar 59-64 cm dan bobot berkisar 1.208,5-1.849,5 g. Semua ikan arwana (11 ekor) dipindah ke luar ruangan, dipelihara dalam bak beton (5 m x 2 m x 1.2 m) dengan media air yang diputar menggunakan pompa dan bak pemeliharaan ditutup dengan jala. Pakan diberikan sama seperti saat adaptasi. Pengamatan keberhasilan pemijahan ikan dilakukan setiap saat dengan mengetahui ada tidaknya telur yang dierami dalam mulut arwana jantan. Pengeluaran larva dari dalam mulut induk jantan dilakukan setelah telur dierami selama 1-1,5 bulan. Hasil penelitian menunjukkan bahwa setelah 8 bulan pemeliharaan di luar ruangan, arwana silver jantan terlihat mengerami telur dalam mulutnya pertama kali dan menghasilkan larva sebanyak 17 ekor, kemudian berturut-turut menghasilkan larva setiap bulan pada bulan ke-22, 23, dan 24 berkisar 25-107 ekor/induk/bulan. 

Silver arowana (Osteoglossum bicirrhosum) is an ornamental fish introduced from Brazil and has been popular among fish collectors. The objective of this research was to determine the optimal spawning technique of silver arowana in controlled tank. Tagged male and female of arowana broodstock were adapted in 3 m x 2 m x 1 m indoor concrete tank with stocking density of 12 individual/tank. Lift frogs (50 g) and raw fish (360 g) were given as feed once per two days. After ten months of rearing, the total length of silver arowana broodstock varied from 59 to 64 cm and body weight ranged from 1,208.5 to 1,849.5 g. Eleven individuals of silver arowana broodstocks were stocked in 5 m x 2 m x 1.2 m out door concrete tank in which the water media was recirculated using water pump and rearing tank were covered with net. The feeds given were the same as during the adaptation process. Observation of breeding was done regularly by observing whether the eggs were already in the male broodstock mouth or not. The process to collect the larvae out of the male broodstock mouth was done after the eggs were incubated in its mouth for about 1.0-1.5 month. Result showed that after 8 months of rearing in outdoor tank, male silver arowanas were seen carrying eggs in their mouth for the first time and produce 17 larvae. On average, as many as 25-107 larvae were obtained per broodstock starting from 22nd, 23nd, and 24nd of rearing period.