Resumen
A simple and noble respirometer in acrylic material has been designed and developed by ICAR-AICRP on Plasticulture Engineering and Technology Centre at ICAR-Central Institute of Freshwater Aquaculture to study the oxygen consumption by fry, fingerling and advanced fingerling stages of fishes. The instrument is transparent, can be completely sealed air tight, and can store water and fish for experimentation. Water can be filled or drained manually at desired intervals, and the inlet and outlet hubs are fixed with screens to protect the fish seed to escape out of the respirometer during experimentation or water flow. Two models of respirometer were fabricated having dimensions of 10?x 10?x 10? and 11?x 11?x 11? with 18 L and 22 L water storage capacities respectively. The components of the respirometer are the transparent water tank with outlet hub containing drainage valve, transparent covering lid with inlet hub containing inlet valve and airway cap. The airway cap is provided in the lid to make a way for air to pass into the tank while draining water or out of the tank during filling of the water. The operation of the respirometer involves filling the tank with water, stocking the fishes, covering it with the lid, taking water samples for oxygen estimation in the start and end of the experiment.