Effects of Artificial Substrate on Growth Performance, Survival and Production of Freshwater Prawn, Macrobrachium rosenbergii (de Man 1879) in Cages in Laguna de Bay, Philippines

The effects of the number of artificial substrates on growth performance, survival and production of freshwater prawn, Macrobrachium rosenbergii (de Man 1879) were evaluated in cages in Laguna de Bay, Philippines. Juvenile prawns (1.97+0.27 g; 5.52+0.19 cm) were stocked in cages (L x W x D: 2 x 3 x 2 m or 12 m³) at 20 pieces m^-3. Three treatments with three replicates each were used: T1= without substrate; T2 = with 6 pieces artificial substrates and T3 = with 12 pieces artificial substrates. After 160 days, mean weights were 46.10 g, 45.57 g and 52.20 g in T1, T2 and T3, respectively. The water quality parameters were favourable throughout the experimental period. Production was highly significant among treatments (P 0.01). Highest total production was recorded in T3 (17.90 kg) and T2 (16.40 kg) while T1 has the lowest production (12 kg). Survival was significantly different among treatments (P 0.05). Highest survival was recorded in T3 (85.83%) and T2 (83.05%) and the lowest was observed in T1 (63.19%). Survival and production were greatly influenced by the increased number of substrates. The higher the number of artificial substrates installed, the greater the survival and production of prawns.