PERKEMBANGAN EMBRIO DAN LARVA PADA DOMESTIKASI IKAN CUPANG (Betta rubra Perugia, 1893)

Abstract

Salah satu jenis ikan cupang alam yang menarik perhatian adalah cupang Betta rubra Perugia, 1893; yang merupakan jenis endemik dari perairan Banda Aceh. Status B. rubra di habitat aslinya sudah mulai sulit diperoleh sedangkan budidayanya belum berkembang. Oleh karena itu, informasi tentang embriogenesis dan perkembangan stadia awal ikan B. rubra sangat diperlukan untuk mendukung keberhasilan pengembangbiakannya. Penelitian ini bertujuan untuk mengetahui embriogenesis dan perkembangan larva ikan B. rubra. Telur dan larva yang digunakan berupa hasil pemijahan alami B. rubra di Balai Riset Budidaya Ikan Hias, Depok. Parameter yang diamati yaitu fase embriogenesis, perkembangan larva, dan benih ikan B. rubra. Pengamatan embriologi di mulai setelah ikan memijah sampai telur menetas, sedangkan perkembangan larva di mulai dari larva menetas sampai menjadi benih atau perkembangan telah sempurna. Pengamatan dilakukan setiap hari di bawah mikroskop binokuler Olympus SZX9 perbesaran 8-25 kali. Hasil penelitian menunjukkan bahwa perkembangan embrio telur B. rubra terjadi selama enam hari atau 144 jam hingga menetas menjadi larva pada suhu 27°C-28°C. Perkembangan embriogenesisnya yaitu hari pertama setelah memijah di mulai dengan pembelahan awal; hari kedua: blastula; hari ketiga: gastrula; hari keempat: pembentukan bakal kepala dan ekor; hari kelima: pembentukan ovtic vesicle dan notochorda; hari keenam: menetas. Perkembangan larva H-3—H-4 setelah menetas mata dan mulut mulai membuka; H-5—H-6: terbentuk anus dan kuning telur habis; H-7: peralihan pakan (indogeneous ke exsogeneous) dan metamorfosis terjadi 39 hari atau 936 jam setelah menetas.

Betta rubra Perugia, 1983 is an endemic ornamental fish found in the swamp areas of Banda Aceh. Due to its appealing physical appearance, B. rubra wild population has been heavily exploited. Current aquaculture technology of the species is not yet available which implies an imminent threat to the conservation of this species. Therefore, the domestication the fish species is the first important step toward developing the aquaculture technology of the species which requires specific information on embryogenesis and the development of the early stadia B. rubra. This study aimed to determine embryogenesis and larval development of B. rubra. The eggs and larvae used from the natural spawning of B. rubra wild parents reared in the facility of the Ornamental Fish Cultivation Research Center, Depok, Indonesia. The parameters observed were the embryogenesis and early stages development of the fish from larvae to juvenile. Observation of embryogenesis started from eggs fertilization until hatching. The development of larvae was observed from post hatching until fully developed as fish juvenile. Embryonic and larval development were monitored daily using an Olympus SZX9 binocular microscope with 8x-25x magnification. The results showed that the embryogenesis of B. rubra lasted for six days or 144 hours until it hatched. The development stages of the embryogenesis after fertilization are as follow: division phase on the first day; blastula on the second day; gastrula on the third day; formation of heads and tails on the fourth day; formation of ovtic vesicles and notochordas on the fifth day; hatch on the sixth day. Larval development consists of: eyes and mouth begin to open at three to four days after hatching; anus is formed and the yolk is gone between the fifth and sixth days; intermediate feed (indogeneous to exsogeneous) at seventh day and metamorphosis at 39 days or 936 hours after hatching.