In this presentation i am going to present the procedures included in the manipulation of sex in fish by applying hormone

1. PRESENTATION ON ELP SEED
PRODUCTION
TOPIC – HORMONAL SEX MANIPULATION

2. INTRODUCTION
• Hormonal therapy is a treatment that adds, blocks or
removes hormones to slow or stop the growth of cells that
need hormones to grow.
• Simply, Hormonal sex manipulation is the method by which
sex hormones are applied to manipulate or change the sex
to get some extra advantages.

3. HORMONES
• Two types of masculinizing hormones are used –
17 alpha methyl testosterone and
17 alpha ethyl testosterone
• Two feminizing hormones are used –
17 beta estradiol and diethylstilbestrol
• The above hormones can’t change the sex of 100%
population.

4. TYPES OF FISHES BASED ON HORMONAL
ACTION TIME
• There are two major types of teleost according to labile period –
the first group includes species in which differentiation occurs just
following hatching and lasts for a short period of 10–40 days (e.g.
ornamental fishes like poecilids, anabantids and others like
cichlids).
The second group comprises food fishes such as salmonids and
cyprinids, in which differentiation occurs during late juvenile stage
and lasts for a period of 150–500 days.
Poecilid species are amenable to hormonal sex reversal during
embryogenesis and post-maturity stages. So amenability for sex

5. HOW THE HORMONE WORKS
Masculinizing hormone
• When MT or ET is applied Spermatogenic
cysts with cells in early stages of
development were predominating and were
distributed throughout the entire gonad.
The oocytes were reduced in number and
only the small, developmentally younger
ones were seen in areas between the
spermatogenic cysts.
Feminizing hormone
• In the case of E (estradiol) and
DES(diethylstilbestrol) -treated fishes,
testicular tissues were not observed in
the developed ovaries.

6. HORMONE PREPARATION
• Stock solution of 17α-methyltestosterone was formulated by
dissolving the 17 α-MT in ethanol at a concentration of
1mg/ml for egg immersion purpose which was safely
maintained at dark cool place because it is photosensitive.
Various hormone concentrations were prepared by adding
1.5, 3, 4.5 and 6ml to 10 liters of water to obtain 17 α-MT
concentrations of 150, 300, 450 and 600 ug/L

7. METHODS OF HORMONE ADMINISTRATION
• Immersion method – The eggs that are collected are
immersed in the stock solution of hormone ( contains
hormone and DMSO ) having concentration of 1mgml in
general which can be modify according to the requirement.
• Feed method - hormones are given by mixing them with the
feed
• Inject method - hormones are injected directly into fish
body by syringe.

8. ADVANTAGES OF HORMONAL SEX
MANIPULATION
• Production of single sex populations offers several
advantages in fish culture, including enhanced growth and
preventing unwanted reproduction.
• Hormones have been used to control the sex of the fish, a
means of enhancing growth by preventing the drain of
energy by reproductive activities.

9. CONCLUSION
• The goal of sex control differs from species to species.
• Before making any effort for the developemental of sex
control technology , it is essential to consider the biological
characteristics of the species.
• For successful sex manipulation, the timing, dosages and
the method of hormone treatment should be standardized.
• While applying the sex reversal technology for commercial
scale culture, effect population size should be taken into
consideration.e

10. FLOW CHART