A Comparative Study Between the Growth Rates and Performance Efficiency of the Nile Tilapia Farmed in Lake Nasser and the Northern Delta: An Attempt to Improve its Aquaculture

This study was conducted to investigate the growth rates and performance of the Nile tilapia from two distinct geographical regions while being cultivated under the same aquaculture conditions. Lake Nasser fish (LNF) were transported from Aswan south of Egypt to the Serw Fish Research Station (SFRS), located in the northern Delta, where acclimation process and rearing experiment was conducted. The average initial weight of fingerlings from both the LNF and Serw fish (SF) strains was 100 ± 15g. The fish were manually sexed and were stocked at a density of 5 fish per cubic meter in 15m³ triplicate groups of concrete tanks, with separate tanks for each sex, all under the same conditions of SFRS. Fish were fed 35% crude protein diet for 60 days. LNF was significantly better than SF in most growth performance parameters (P≤ 0.05). The average daily gain was significantly doubled in LNF than SF (3.21, 1.77, respectively), which leads to average weight of LNF almost 292.25g (P≤ 0.05). SGR and Fulton’s condition factor were significantly higher in LNF than in SF, recording 2.06, 2.09 and 1.18, 1.77, respectively (P≤ 0.05). On the other hand, the survival rate of SF was higher than that of LNF. The reproductive efficiency parameters namely, absolute fecundity, relative fecundity to length, gonado-somatic index exhibited highly significant increase in LNF than in SF (P≤ 0.05). In conclusion, the present study revealed that the Nile tilapia inhabiting Lake Nasser has good characteristics that should attract the farmers and stakeholders. Partial exchange of the broodstock is recommended in the northern tilapia farms and hatcheries with the Lake Nasser tilapia to improve the aquaculture sector.