Physiological Responses of Angolan Tilapia (Oreochromis Angolensis) in Different Salinity Gradients
Abstract:
Several species of tilapia are considered ideal for aquaculture in different production systems due to their rusticity. Oreocrhomis Angolensis, originally found in fresh and brackish waters, is a little-known species and little explored by aquaculture. It can be a candidate for generating strong hybrids that can be used for industrial production. This study aimed to evaluate the performance of Oreochromis angolensis in different salinities. For this purpose, 108 juveniles of 1.37 ± 0.23g and 3.57 ± 0.25cm, acclimated for 8 days and cultured for 30 days in the following sa linities: 5; 10; 15; and 20g, three replicates each, in 9-liter tanks with aeration and thermostated bath. Biometrics and analysis of water quality parameters were performed. Weight gain was lowest in the 5g treatment and highest in the 20g treatment, with an average of 0.60g. TCE was not limited by salinity. Feed conversion was not good in any of the treatments. Survival was 90% in the 20g treatment and 100% in the others, during the 30 days of culture. Therefore, Angolan tilapia is a species with a wide euryhaline capacity and these results will help future studies regarding the appropriate salt concentrations for the growth of this species in different salinities.
