| Popis: |
This study aimed to determine the optimal live feed regime (i.e., initial feeding moment, density, and frequency) for maximum growth and survival of pangasius catfish (Pangasianodon hypophthalmus) early life history stages. The first experiment assessed the optimal initial feeding moment (30, 36, 42, and 48 h post hatching, hph). The second experiment assessed feeding density (3, 5, 8 and 11 individuals per mL, ind/mL) at the optimal initial feeding moment (30 hph) which was the best result from the first experiment. The third experiment assessed optimal feeding frequency (1, 2, 4, and 6 times per day) at the optimal initial feeding moment (30 hph) and density (8 ind/mL) which was drawn upon from the second experiment. All experiments were conducted in 20 L containers containing 20 hph P. hypophthalmus larvae at a density of 10 ind/L and fed rotifers (Brachionus angularis) for 3 days and then water fleas (Moina macrocopa) for 7 days. The first experiment demonstrated that larvae initially fed at 30 hph exhibited a significantly higher survival rate (24%) than larvae initially fed at 36, 42, and 48 hph (19%, 16%, and 16%), respectively. The second experiment demonstrated that larvae fed at 8 and 11 ind/mL densities exhibited significantly higher survival rates (32% and 32%) than larvae fed at 3 and 5 ind/mL densities (13% and 23%), respectively. The third experiment demonstrated that the highest survival rate (66%) was obtained when larvae were fed 6 times per day. These results provide valuable insights regarding the optimal live feed regime for better growth and survival of P. hypophthalmus larvae, which are commercially important and numerously cultured throughout the Mekong Delta region. |
