Effect of different combinations of initial weights and stocking densities on growth parameters and culture economics of earthen ponds raised Nile tilapia

Abstract

This study aimed to evaluate the effect of both different initial weights and stocking densities on growth performance, productivity and the total economic revenue of Nile tilapia reared in earthen ponds under Egyptian conditions. Twelve earthen ponds with an area of 2 feddans were divided into two groups according to the initial fish weight, fingerlings (10 g) and fry (0.3 g.), Each group had three carrying capacities of 30, 40, and 50 thousand fish / pond. The water quality measurements were sustained at recommended limits, temperature ranged from 23 to 29oc and the pH from 7.5 to 8.8, while the dissolved oxygen was kept at range from 5.4 to 7.9 mg/l. The growth measurements revealed that the Fing 50 treatment had superior total production, though the percentage of larger fish were accomplished by both group Fing 40 and Fing 30. This was reflected by economics of production, where the highest return was generated by treatments Fing 40, followed by Fing 50, and the best return on costs was in favor of the Fing 30 treatment. In reference to this study findings, a stocking density of 30 and 40 thousand monosex tilapia fingerlings are recommended for culture in earthen ponds under the similar conditions in Egypt.