Evaluation of nile tilapia (oreochromis niloticus, linnaeus 1758) fingerling production at the aquaculture demonstration centre - ashaiman, ghana.

ABSTRACT

The Nile tilapia, Oreochromis niloticus (Linnaeus, 1758) fingerling production is important for the continual expansion of the global tilapia aquaculture. This study evaluated the Akosombo Strain Nile tilapia fingerling production at the Aquaculture Demonstration CentreAshaiman, Ghana. A total of 1350 female brooders of mean weight 150.7±41.8 g and 450 males of mean weight 218.6±63.1 g were stocked into nine outdoor concrete tanks of size 50 m2 each in a sex ratio of 3:1 respectively for 14 days. From the estimated 675,000 eggs produced by the females, a total of 138,631 fry were harvested resulting in 20.5% hatching success. The survival rate of the fry after hormonal treatment was 79.5% with estimated FCR of 1.46 and SGR of 6.05±0.35%day-1 . For growth to the fingerling stage, the fry were stocked into an earthen pond of size 1200 m2 for 24 days at an initial weight of 0.23±0.04 g. The final mean weight of fingerlings harvested was 2.47±0.55 g with FCR of 1.09, SGR (3.26±0.18%day-1 ) and a survival rate of 75.3%. The estimated final standing crop was 1708.4 kg ha-1 . Results from statistical analysis indicated that there were no significant differences among fry produced in the breeding tanks (p=0.73). Water quality measurements in the breeding tanks, fry tanks and fingerlings pond were respectively 29.03±0.51oC, 28.07±1.79oC and 27.07±1.68oC for temperature; 3.56±0.04 mgL-1 , 3.62±0.18 mgL-1 and 3.74±0.21 mgL-1 for DO; 7.38±0.19, 7.35±0.18 and 7.56±0.25 for pH; salinity were 0.23±0.01‰, 0.24±0.02‰ and 0.29±0.02‰, and ammonia levels of 0.12±0.06 mgL-1 , 0.01±0.002 mgL-1 and 0.04 ± 0.01 mgL-1 respectively. The study concludes that the Centre can increase production of fingerlings if the current management practice at the breeding stage of production is improved.