Abstract:
Tilapia referred to as the ‘aquatic chicken’ is a popular freshwater species.
Tilapia quickly gained popularity among fish farmers due to its rapid growth
rate and tolerance to a wide range of environmental conditions. The major
problems linked with Nile tilapia (Oreochromis niloticus) in aquaculture are
early reproduction and slow-growing females in the progeny. To solve this
problem, production of all male tilapia in Sri Lanka was carried out by oral
administration of 17-methyltestosterone (MT) mixed with feed. However,
this strategy is very harmful to the environment. Therefore, this study sought
to determine the efficiency of egg immersion in an androgen solution, find
out the most effective MT concentration for producing sex-reversed tilapia
as an alternative to oral administration, and determine the cost-effectiveness
of the egg immersion method. Stage III eggs were immersed at
concentrations of 1.2 mg/L and 1.5 mg/L of MT for 72 hours and 96 hours.
The hatchability and survival rate, growth parameters, the proportion of
males and females and cost factors were determined as components of the
research. Immersing eggs in 1.5 mg/L for 96 hours resulted in the
significantly highest percentage of male Nile tilapia, with 95.00% of fish
being male (p<0.05, ANOVA) and at a comparatively cost-effective.
Literature suggests that oral administration results in greater environmental
impacts due to the accumulation of hormones in water bodies. This study
demonstrates the feasibility of this method and highlights its potential to be
more cost-effective compared to traditional oral delivery techniques while
reducing environmental impact.
