PERTUMBUHAN DAN PERKEMBANGAN GONAD IKAN BAUNG (Hemibagrus nemurus) KETURUNAN G-1, G-2, DAN G-3

Abstract

Ikan baung (Hemibagrus nemurus) telah berhasil didomestikasi oleh Balai Riset Perikanan Budidaya Air Tawar dan Penyuluhan Perikanan, Bogor. Hasil penelitian domestikasi, populasi Cirata memiliki fekunditas dan pertumbuhan yang lebih bagus, populasi ini dikembangkan hingga tiga generasi (G1, G2 dan G3) namun, ada informasi terbatas mengenai perbandingan antara perkembangan gonad dari berbagai generasi ikan. Tujuan penelitian ini adalah untuk mengukur pertumbuhan dan mengamati perkembangan gonad generasi pertama (G-1), kedua (G-2), dan ketiga (G-3). Parameter yang diukur dan diamati meliputi pengukuran panjang, berat, laju pertumbuhan spesifik, morfologi dan berat gonad, diameter oosit, dan indeks gonad somatik (IGS). Pengambilan sampel dilakukan setiap dua bulan dengan mengumpulkan sepuluh sampel ikan dari setiap generasi. Jaringan gonad disiapkan secara histologis dan diwarnai larutan asetokarmin sebagai zat pewarna. Pengamatan menggunakan mikroskop dengan perbesaran 4 x 10. Hasil penelitian menunjukkan bahwa pada usia 222 hari, gonad jantan dan betina secara fisik masih dalam bentuk benang halus. Namun, karakteristik sekunder pada ikan jantan seperti papila sudah mulai tampak meski tidak terlalu jelas. Pada usia 283 hari, ukuran oosit berkisar antara 0.025-0.05 mm. Pada usia 345 hari, telur mulai terlihat dengan ukuran oosit G-1, G-2, dan G-3 masing-masing berkisar antara 0.59 ± 0.24, 0.39 ± 0.15, dan 0.48 ± 0.15 mm. Setelah usia 406 hari, perkembangan gonad mencapai TKG-III dengan diameter rata-rata oosit G-1, G-2, dan G-3 berkisar antara 1.13 ± 0.11, 0.92 ± 0.18, dan 1.11 ± 0.10 mm dengan IGS dari G-1, G-2, dan G-3 dari 8.20%, 0.98 %, dan 4.8%, masing-masing. Tidak ada perbedaan yang signifikan antara diameter oosit G-1, G-2, dan G-3 (P£0,05). Keturunan kedua (G-2) merupakan generasi terbaik untuk dijadikan kandidat budidaya. Asian redtail catfish (Hemibagrus nemurus) has been successfully domesticated by the Research Institute for Freshwater Aquaculture and Fisheries Extension, Bogor. The results of the domestication of Cirata population have better fecundity and growth, this population has been developed for up to three generations (G1, G2 and G3) however, there is limited information regarding the comparison between the ovarian development of different generations of the fish]. This study’s aim was to measure the growth and observe the ovarian development of the first (G-1), second (G-2), and third generations (G-3). The parameters measured and observed included the measurements of length, weight, specific growth rate, morphology and gonad weight, oocyte diameter, and somatic gonad index (IGS). The sampling was carried out every two months by collecting ten fish samples of each generation. Gonad tissues were histologically prepared and stained asetocarmine solution as the coloring agent. The observations used a microscope with a magnification of 4 x 10. The results of the study showed that at the age of 222 days, the male and female gonads were physically still in the form of fine threads. However, secondary characteristics in male fish such as papillae have begun to appear though not very clear. At the age of 283 days, oocytes’ sizes ranged between 0.025-0.05 mm. At the age of 345 days, the eggs were starting to be visible with the oocyte sizes of G-1, G-2, and G-3 ranged between 0.59 ± 0.24, 0.39 ± 0.15, and 0.48 ± 0.15 mm, respectively. After the age of 406 days, the development of gonads reached gonad maturating level III with the average diameter of the oocytes of G-1, G-2, and G-3 ranged between 1.13 ± 0.11, 0.92 ± 0.18, and 1.11 ± 0.10 mm with the IGS of G-1, G-2, and G-3 of 8.20%, 0.98%, and 4.8%, respectively. There was no significant difference among the oocyte diameters of G-1, G-2, and G-3 (P£0.05). The 2nd generation (G2) is the best generation to be a candidate aquaculture.