2. INTRODUCTION
Hybridization IS THE ACT OF BREEDING between two species
/genera ,which ordinarily are not interbreeding.
It is well known that hybridization refers to cross-breeding between
either members of different races or strains of the species (intra-
specific);or between two species of the same genus (tnter-specific)
and between species belonging to different genera (intergeneric ).
Hybridization is usually aimed to combine positive traits of parent
species in their hybrid offspring . The positive traits may include
better growth , resistance to disease / changed environment , meat
quality early or late maturity , better fecundity and so on.

3. INTERSPECIFIC HYBRIDIZATION
Interspecific reciprocal hybrids where produced
among indian major carp by crossing labeo rohita
with labeo calbasu these hybrid have been son
some traits of interest for aquaculture i.e hybrid
exhibited faster growth the hybrid the slow
growing parents the calbasu.
For :- example
Male female results
Labeo rohita laboe calbasu rohu calbasu
Labeo calbasu labeo rohita calbasu rohita
Labeo bata labeo rohita bata calbasu
Labeo bata labeo calbasu bata calbasu
Labeo calbasu labeo genius calbasu genius

4. INTER-GENERIC HYBRIDIZATION
Extensive work has been carried out on tnter-generic hybridization
among the species or three genera i.e catla labeo and cirrihinus as
many as 30 / . inter generic have been produced and evaluated for
their positive traits how ever only few of then .these found to posses
some positive characteristics which are useful for aquaculture.
For:-example
Male Female Results
Catla catla Labeo rohita Catla rohita
Catla catla catla mrigala Catla mrigala
Laboe rohita catla mrigala Rohu mrigala
Laboe mrigala Laboe calbasu Mrigala calbasu
Cirrihinus rewa Labeo rohita Rewa rohu

5. NATURAL HYBRIDIZATION IN FISHES
It confined to only inter-specific( It takes place in between the
individual of the same species)
.Quite a number of inter-specific hybrids have been found to be
viable and fertile.
It is more common In freshwater fishes than in marine ones.it is
believed that since the freshwater habitat provoides suitable
conditions for that as compare to ocean.
The reproductive isolation mechanism in fishes inhabiting freshwater
have not yet been developed perfectely leading to higher frequency
of hybridization in themthe frequency of natural hybridization in the
fresh water fishes has increased due to various conditions

6. FACTORS PROMOTING NATURAL
HYBRIDIZATION IN FISHES
01.BIOLOGICAL
• External fertilization habit.
• Behavioural isolation mechanism that prevent inter-specific breeding not
perfected in several group of fishes.
02.PHYSICAL
- Over-laping of spawning grounds of relatedspecies due to habitat changes by
the construction of dams and canals.
03.ANTHROPOGENIC
- Purposeful or accidental introduction of non – native species.
- unequal abundance of the males and females of a species due to fishing
pressure or other reasons.

7. ARTIFICIAL HYBRIDIZATION IN FISHES
•IT is not restricted to inter-specific like the
natural hybridization ,Thus attempting artificial
hybridization , it is important to gather
knowledge on the taxonomy ,biology,karyology
and the economic traits of the concerned
species.
•The two species chosen for the purpose of
hybridization should be taxonomically close
.e.g breeding season should be
overlaping, chromosome number should be

8. WAYS BY WHICH ARTIFICIAL
HYBRIDIZATION CAN BE CARRIED OUT
•By Simple Cohabitation. (E.G Tilapia)
•By Hormone Treatment And Co-habitation.(E.G
Catla,rohu And Mrigal)
•By Hand Stripping.(E.G Cat Fishes
Heteropneustes,claris Etc )

9. OBJECTIVE
-TO BRING GENITIC MODIFICATION
-TO GET DISEASE FREE HYBRID
-TO ACHIVE GENOMIC CHARACTERSTICS,SURVIVAL,GROWTH,REPRODUCTIVE ABILITY
AND SEX DISTRIBUTION IN THE F1 GENERATION.

10. CONCLUSION
• Here We Conclude That The Hybridization In Fishes
Is More Benificient In Respect To Economic Traits
And It Is Only The Way To Produce Desirable Traits
In The Form Of Hybrids .
• Moreover Hybridization Is A Detrimental Process
Since Two Incompletely Diverged Genomes Are
Combined In The Hybrid,

11. •THANK
S