Growth performance of black tiger shrimp (Penaeus monodon) in substrate based zerowater exchange system

Abstract

To evaluate the effect of periphyton based system, an on–station grow-out trial of black tiger shrimp, Penaeus monodon was carried out for 130 days using with (Ts) and without (Tc) submerged substrates. P. monodon was stocked at 8 nos. m-2, and bamboo substrates (1.8 × 0.06 m) were fixed in treatment ponds @ 2000 numbers ha-1 for development of periphyton. Provision of substrate increased the transparency (p<0.01) and reduced the turbidity (p<0.05) in treatment ponds compared to control. Similarly, comparatively lower level of total ammonia –N and nitrate–N were recorded in substrate based ponds compared to control. Periphyton biomass in terms of dry matter and ash free dry matter over substrates were 5.9±0.7 and 3.0±0.4 mg cm–2 respectively. Chlorophyll a level in water column was 15.22±6.97 and 19.06±8.68 μg L-1 in Ts and Tc ponds respectively. At the end of the grow out trial, a higher average production of 1640 kg ha-1 with an average body weight (ABW) 25.85±2.62 g was obtained in Ts compared with control, Tc (1390 kg ha-1 production and 22.00 ±2.83 g ABW). About, 29% improvement in feed conversion ratio (1.15±0.42) noticed in substrate based ponds compared to control ponds (1.48±0.02). Regression trend for length–weight analysis indicated that growth exhibited an isometric pattern with better Fulton condition factor (0.83) in tiger shrimp reared in substrate based system than in control ponds (0.82). Better growth performance of tiger shrimp in substrate based system indicates utilisation of available natural food and natural productivity as periphyton by cultured shrimps.