The most successful sex reversal and breeding program with the greater economic impact in tilapia farming has been the production of all males XY populations of Nile tilapia from YY males In 2001, biologist Dr. Graham Mair concluded that YY males technology provides a robust and reliable solution to the serious and widespread problems of early sexual maturation, unwanted reproduction and overpopulation in tilapia culture.

1. SEMINAR ON
“PRODUCTION OF SUPER
MALE”
PRESENTED BY-
AKSHAY MANDAL
2nd SEMESTER , M.Sc MARINE BIOTECHNOLOGY
ANDHRA UNIVERSITY
Registration no- 722211224002

2. INTRODUCTION
 The most successful sex reversal and breeding program with the greater
economic impact in tilapia farming has been the production of all males
XY populations of Nile tilapia from YY males
 In 2001, biologist Dr. Graham Mair concluded that YY males technology
provides a robust and reliable solution to the serious and widespread
problems of early sexual maturation, unwanted reproduction and
overpopulation in tilapia culture.

3. METHOD OF PRODUCTION OF YY SUPER MALE
1ST STEP-
• For production of all male population or YY super male, the first step is to feed the sexually
undifferentiated fry a ration, containing estrogen in order to produce sex reversed females. When
the hormone treated fish can be sexed, they will fall into three categories-
1. Normal XX female
2. Normal XY male
3. Sex reversed XY females
• The normal XY males should be culled, because they are of no use in this breeding program.
Normal XX female should also be culled. But it is difficult to separated normal XX females from
the XY females by examining external sexual characteristics

4. METHOD OF PRODUCTION OF YY SUPER MALE
2nd STEP-
• Second step involves the progeny test of the females in order to identify and save
the XY females; and to identify and cull the XX females. This is accomplish by
crossing the female with a normal male and then each family is maintained in an
individual hapa or pool with the offspring can be sexed.
• Females that produced offspring with a 50:50 sex ratio are XX (female) and
should be culled. These that produce 75% offspring are XY males and should be
saved. Among 75% offspring, two thirds are normal XY males and one-third is YY
super males. Super males are capable of true breeding and producing only male
offspring.

5. METHOD OF PRODUCTION OF YY SUPER MALE

6. METHOD OF PRODUCTION OF YY SUPER MALE
3rd STEP-
It is impossible to separate males from supermales by examining of
external sexual characteristics . So, a second round progeny testing is
necessary to identify and keep the super males and to identify; and to
cull the normal males. This accomplished as the same previous way.
The males that produce offspring with 50:50 sex ratio are culled while
those that produce 100% males are kept and pampered because they
are super males fish that are capable of producing 100% male
offspring without the use of hormones.

7. METHOD OF PRODUCTION OF YY SUPER MALE

8. ADVANTAGES OF PRODUCTION OF SUPER MALE
 In certain fish species, males have faster growth rates and reach larger sizes
compared to females. By producing all males population, it can result higher
production efficiency and improved market value.
 Preventing unwanted reproduction is crucial to maintain control over the
population and prevent overcrowding. By producing all male populations,
unwanted reproduction is significantly reduced, as there are no females
present to produce offspring.
 In some cases specially in ornamental fishes, males are more colorful &
valuable, this is also an another advantages of production of super male
population.

9. THANKS