Substrate based black tiger shrimp, Penaeus monodon culture: Stocking density, aeration and their effect on growth performance, water quality and periphyton development

Abstract

Growth performance of black tiger shrimp Penaeus monodon juveniles were evaluated in two outdoor experimental trials as a function of two stocking densities and aeration system in substrate based shrimp culture. The experiment 1 had 2×2 factorial design with two levels of stocking density and two management systems (with and without substrate addition) resulting in four treatment, each with three replicates. The 12 FRP tanks (1000 L) were stocked with P. monodon juveniles (1.08 ± 0.12 g) at 10 and 20m2 as first factor, and with substrate (10+S and 20+S) and without substrate (10-S and 20-S) as second factor. In experiment 2, effect of aeration in substrate system was evaluated in 1000 L FRP tanks with P. monodon (3.89 ± 0.12 g) in four treatments: provision of aeration (A) with substrates (S+A), without substrate (C+A), and absence of aeration with (S-A) or without substrate (C-A). In both experiments, bamboo substrates (5×2×1 cm) were installed in substrate based groups which generated an additional 540 cm 2 surface area for periphyton development. Formulated feed containing 38% crude protein was provided in both the experiments. In trial 1, stocking density did not significantly affect water quality parameters, whereas provision of bamboo substrate significantly reduced nitrate-N level (P < .05). Both stocking density and substrate addition played significant role in shrimp survival by 14–30% improvement due to substrate addition while 18–34% changes in survival due to stocking density. The substrate addition improved FCR significantly (P < .05) by 21–33% compared to without substrate based treatments. In experiment 2, lack of aeration significantly affected the dissolved oxygen level (P < .05) in the water column, while it does not significantly affected the growth parameters, and substrate addition alone improved 21% of survival rate of shrimp. Estimation of periphyton biomass revealed that stocking density and aeration effects resulted 60 and 40% significant (P < .05) difference in ash free dry matter in periphyton biomass. From the present trials, it can be concluded that stocking density of shrimp plays an important role in optimum utilization of periphyton developed over submerged substrates. Also, insignificant growth performance of shrimps reared in low density substrate based systems without aeration indicated that the system has the potential to adopt by small scale shrimp farmers for sustainable ecofriendly farming.