Evaluation of Periphyton Quantity on Different Natural Substrates in Freshwater

The present study was conducted to evaluate the periphyton quantity in different natural substrates for natural feed production in fibreglass reinforced plastics (FRP) tanks under freshwater. Experiments were conducted in outdoor FRP tanks (1500 litres) to observe periphyton quantity on three types of natural substrates such as split bamboo pole, coconut coir and coconut shell, which were placed inside the FRP tanks filled with freshwater for duration of 45 days. Observations were made in every 15^th day for growth of periphyton both qualitatively and quantitatively on the three natural substrates. The mean value of periphyton quantity recorded for different substrates reared in freshwater showed highly significant positive correlation (p < 0.001) with days of culture. Student's ‘t’ test analysis confirmed that mean values of periphyton quantity recorded in freshwater with duration showed significant differences (p < 0.05) between different substrates. From this study, it was observed that among the different substrates used for natural periphyton growth, split bamboo pole exhibited higher periphyton quantity than coconut coir and coconut shell.