At the beginning and end of the experiment, fish were measured from the tip of the snout to the end of the caudal fin with an acrylic measuring board and a measuring tape, and weighed on a Labtronic Scientific digital scale (model 21-2544-09). The survival (taking into account the initial number and the final number of fish) and biomass gain (g of harvested tilapia – g stocked tilapia) were calculated in each pond.