Utilization of Ipomoea carnea as substratum for the production of periphyton and its impact on the fish production in irrigation tanks

The term ‘periphyton’ is the assemblage of sessile or attached micro organisms on any substrate. The varieties of organisms found in periphyton are algae, fungi, bacteria, protozoa, zooplankton and other invertebrates. The main objective of the present study was to find the suitability of periphyton-based aquaculture under field conditions by utilizing locally available aquatic weed as a substratum for development of periphyton in small rural tanks to enhance the fish production for livelihood of resource-poor fishermen. The tanks selected for experiment were stocked with fish seed (26–30 mm total length) of two species of Indian major carps, namely catla (Catla catla) and rohu (Labeo rohita). The results of physicochemical parameters indicated that water is alkaline in nature. The communities of Cyanophyceae, Chlorophyceae, Bacillariophyceae and Euglenophyceae constitute the phytoplankton bulk and the Cyanophyceae was found to be rich and dominated in the control and experimental tanks. Zooplankton was represented by Rotifera, Cladocera, Copepoda and Ostracoda. Eleven species of fishes were found in experimental and control tanks. In periphyton populations, 5 genera of Chlorophyceae, 8 genera of Cyanophyceae, 8 genera of Bacillariophyceae and 3 genera of macro invertebrates were found in the experimental tanks. This research work demonstrated two fold enhancement of fish production in weed infested small irrigation tanks by adopting periphyton concept for the first time under field conditions, utilizing locally available weed as substratum. Such increased fish production has resulted in additional income to local resource-poor fishermen assisting in their livelihood.