Authors : S.A. Osofero , S.O. Otubusin and J.A. Daramola
Abstract: A study was carried out to evaluate the effect of varying stocking densities on the growth, survival and yield of Tilapia (Oreochromis niloticus Linnaeus 1757) at the freshwater reservoir (average depth, 1.7 m) of the University of Agriculture Abeokuta, Nigeria for a period of 3 months. Tilapia juvenile with a mean weight of 29�4.81 g were randomly (Complete Randomized Design) stocked at 50, 100, 150 and 200 specimen per cage (1 m3) were fed with commercial feed (34.55% Crude Protein). Twenty percent of stocked fish was sampled for growth forth nightly. P rofit index of the fish harvested under each treatment was evaluated. Relevant physico-chemical parameters like pH, conductivity, temperature, water depth and dissolved oxygen were also monitored forth nightly. The experimental fish and fish carcass (before the experiment and at harvest) from each treatment were analysed in replicates for their proximate composition. The growth response of the fish under the varying stocking densities was assessed, there were no significant differences (p>0.05) in Daily weight gain, Specific growth rate, Final weight, Relative growth rate, Feed Conversion Ratio (FCR), Survival, protein efficiency ratio for all the treatments, however there were significant differences (p< 0.05) in fish production (harvest), profit index, crude protein, crude fat and ash composition of the fish carcass (at harvest). As stocking density increased, the crude protein content of the fish carcass decreased indicating an inverse relationship. The stocking density of 150 juvenile/cage with a final weight of 82.74 g per fish; FCR, 2.15; Survival, 99.35% and Fish production of 24.79 kg cage 1 was considered best on the basis of the profit Index of 2.01 compared with the range of 1.45 to 1.82 for the other three treatments.
S.A. Osofero , S.O. Otubusin and J.A. Daramola , 2007. Effect of Stocking Density on Tilapia (Oreochromis niloticus Linnaeus 1757)Growth and Survival in Bamboo-Net Cages Trial . Journal of Fisheries International, 2: 182-185.