Dynamics of plankton in substrate based fish & prawn culture

Abstract

A study was conducted to evaluate the effect of periphyton substrate on plankton dynamics. Sugarcane bagasse is used as a substrate for periphyton growth. Three experimental treatments were included; T0 (Control), T1 (Substrate + feed) and T2 (substrate only). Indigenous fishes like Labeo fimbriatus (Bloch,1795), Barbodes carnaticus (Jerdon,1849) and freshwater prawn, Macrobrachium rosenbergii were stocked in tanks in 3:3:4 ratio at 10000/ha, for a period of 180 days. Bagasse substrate influenced the water quality parameters viz., pH (6.73 – 8.17), dissolved oxygen (6.70 – 8.50). Low concentration of Ammonia (0.068 – 0.140 mg/l) and Nitrite (0.046 – 0.082) was observed in substrate based ponds. A decreasing trend was observed in periphyton DM, AFDM and ash content value in both the treatment near the termination of experiment, which indicates effective grazing on periphyton by cultured fish species. Also, pigment concentration was also found high in substrate ponds. The result demonstrate that sugarcane bagasse can effectively use as a substrate for enhancing the population of plankton.