Male tilapia fish grow faster and much bigger than the females. The males normally weigh frorn 600-800 gms in four months and can even grow bigger, but the females reach only as much as 150 gms within the same period. Because the female tilapia reproduces fast, the over population in the
pond retards their growth and causes the death of many.
If the males and females would be put together, it is not easy for harvest time because their growth or sizes would be varied.
Materials:
1. Seven (7) inverted (mosquito) nets,
2. Formula SRT-95 (hormone).
Method:
1. Place in the inverted nets (in the pond) the newly hatched fingerlings from the mouth of the mother tilapia.
2. Feed them with the formula.
3. Do this in 21 days. A kilo of hormone can feed 6,000 fingerlings.

The percentage of reversal when fed with this hormone is 95-99%. When 10 days are past, the fish will not change sex even when they are fed with the hormones. This was discovered by Dr. Rafael Guerrero of the Central Luzon State University in 1977, based on his doctoral thesis at the Auburn University. He did not keep the information selfishly but shared it with the people that now benefit from it. For this, he was awarded the TOYM award and the S&T IBM Award in 1987.
PCARRD Farmnews Vol X11I Sept 1987