WHY INDUCED BREEDING??
Induced breeding is a technique where
organism is stimulated by particular hormone
or other synthetic hormone or by providing
condition, introduced to breed in captive
The stimulation promotes timely release of
sperms and eggs from ripe gonads.
NEED OF INDUCED
Because of environmental condition like
photoperiod, rain, Temperature, currents of
Insufficient release of hormones in captive
Insufficient of natural foods.
POINTS TO BE KEPT IN MIND
The brooders should be healthy, fully ripe and medium
Large sized breeders are avoided for difficulty in
Dose of the hormone should be calculated, according to
The Artificial Process By Means Of Which
The Extract Of The Pituitary Is Introduced
Inside The Body Of Both The Matured Male
And Female Fishes, Then After Being
Excited, They Lay Eggs In The Pond Water
And Subsequently Fertilization Takes Place
And The Process Is Called Induced
Breeding Of Fishes.
This Process Of Breeding Is Also Known
HISTORY OF INDUCED BREEDING
The technique of induced breeding was first evolved in
Argentina after producing pituitary extract by B. A. Hussay in
Brazilian was the first country to develop a technique for
hypophysation in 1934.
In India, first attempt to induce breeding was made by
Hamid khan in 1937 on Cirrhinus mrigala.
Dr. Hiralal Choudhary applied this technique in minor carps
like Esomus danricus in 1955.
Ramaswamy and Sundarraj(1955-56) first induced to breed
Clarias batrachus and Heteropneustes fossilis.
Choudhary and Alkunhi(1957) – l. rohita, L. bata, C. reba.
Parmeshwaran and Alkunhi (1962) – successfully breed to
exotic Chinese carps like grass and silver carps.
WHY DOES FISH NOT BREED
Many cultural farm fishes like IMC do not breed in captivity. The
reason may be
Environmental and consequently hormonal.
Certain environmental parameters like photoperiods, rain, temperature,
current of water influence the hormonal activity from pituitary and gonads.
Disturbances arise in environment may cause the insufficient release of
hormones in captive conditions and thus, the fish does not breed in
captivity. Other factors like poor foods or insufficient natural foods, exposure
to biocides and other pollutants badly affect the maturation of ovary.
WHY INDUCED BREEDING IS
NECESSARY FOR FISH CULTURE:
IT GIVES PURE SPAWN OF CERTAIN SPECIES OF FISHES UNDER CULTIVATION.
SPAWN COLLECTED FROM NATURAL WATER IS NOT PURE AS BECAUSE SOME
UNDESIRABLE WILD SPECIES MAY COME WITH THEM
IN CULTURE POND. SORTING OF PURE SEED IS QUITE IMPOSSIBLE IN THOSE
STAGES. IN LATER STAGES IT IS POSSIBLE, BUT TIME CONSUMING.
IT ASSURES TIMELY AVAILABLE OF PURE SEED, WHERE AS IN NATURE THE
AVAILABILITY OF SEED IS QUITE UNCERTAIN.
IT CAN FULFIL ANY QUANTITY OF DEMAND IN ANY TIME.
IT ALSO CUTS SHORT THE HOLDING POTENTIAL SPAWNERS OVER LONG
PERIODS IN UNCERTAIN HOPE OF THEIR BREEDING IN TIME. MANY CARPS TAKE
THEIR FULL MATURITY IN CONFINED WATER BUT DO NOT BREED.
THE TECHNIQUE IS VERY SIMPLE AND DOES NOT NEED TOO MUCH TECHNICAL
ASSISTANCE OR KNOWLEDGE. IT CAN BE EASILY LEARNT BY A LAYMAN WITHOUT
THE COST OF EXPENDITURE IS VERY LOW THAN THE NATURAL COLLECTIONS OF
(A). LOCATION OF
Pituitary gland is also known as
This gland in fishes is located at
Sella turcica of sphenoid bone
It is situated on the ventral side of
the brain just behind the optic
chiasma and below the
(B). REMOVAL OF GLAND
REMOVAL THROUGH FORAMEN MAGNUM – The foramen magnum was first exposed
by removing vertebral parts adhering to skull. Fat is removed first by means of forceps and
then cotton piece. A pair of forceps then inserted into foramen magnum dorsally to the
brain and anterior part of the brain now detached and remaining is carefully lifted out
through the foramen magnum. The gland is then located and removed.
REMOVALOFGLANDBYDISSECTINGHEAD– This technique is not used commercially
as because the heads are damaged by this process. At first the head is dissected
using sharp butcher’s knife, a portion of scalp is chopped off in a clean cut with
one stroke. Fat surrounding the brain is removed with the help of cotton. Olfactory
and optic nerves are now severed, and then brain is lifted up and removed. Locate
the gland. The gland may come up along with the brain or may remain behind on
the floor of brain cavity often covered with a membrane. In any case the gland is
carefully removed after separating it from membrane or the brain proper. The gland
must not be damaged or torn.
The first method of removal is less time consuming and economical as the
heads are used for human consumptions later.
I. ALCOHOL PRESERVATION: After collection glands
immediately put in absolute alcohol for defatting and dehydration
After 24 hour’s glands washed with absolute alcohol and kept again
in fresh abs. Alcohol store in refrigerator up to 2-3 years or at room
temperature up to 1 year.
II. ACETONE PRESERVATION: Glands kept in fresh
acetone or in dry ice-chilled acetone inside a refrigerator at -20 0C
for 36-48 hours. 2-3 changes of acetone at about 8-12 hours
intervals glands are taken out of acetone, put on filter paper and
dried at room temperature for one hour and largely practiced in
USSR and USA.
(C). PRESERVATION OF GLAND :
(D). PREPARATION OF GLAND EXTRACT:
Extract of the gland prepared just before injection
Gland weighed and homogenized in distilled water or 0.3% saline
Final volume should be 0.2ml/kg BW of the fish
Centrifuged the suspension
Supernatant used for injection
(E). BROODER SELECTION:
The brooders must be healthy enough and ripe
2 – 4 years of age is generally selected
1 – 5 kg body weight is preferable
PRESERVATION OF GLAND EXTRACT
Preserved extract in glycerin and kept in refrigerator for 24 hours and preserved in
propylene glycol and kept in refrigerator for 30 days with Immersed in 1.5% TCA
for 12 hours and kept in refrigerator for 10 days.
(F).INJECTION TO THE BROODERS:
The pituitary extract is administered into the body of breeders by means of hypodermic
syringe either intra muscular or intra peritoneal.
Determination of correct dosage of pituitary extract to be given to the breeders is very
important and depends upon the size and state of maturity of the recipient (breeders) as well
as upon the state of maturity of the donor for the glands.
Intra-cranial injections preferred in USSR and intraperitoneal in USA and japan.
Intra-muscular injection is most common practice in india.
Intra-muscular injection given at the caudal peduncle or shoulder regions near the base of
the dorsal fin.
Intra-peritoneal injections given at the base of the pelvic fin or pectoral fin.
DOSAGE OF PITUITARY EXTRACT
-Female given 2 doses
1. Initial dose: 2-3mg/kg body weight.
2. Resolving dose / final dose: 6-8mg/ body
-Male given only 1 dose at the time of the
2nd dose given to female (2-3 mg/kg body
-For females of indian major carps one
initial and after 5-6 hours final dose given.
After injection to the brooders, a set of brooders are released into
breeding hapa. In hapa breeding, the hapa is the fine netting,
rectangular in shape and is held by four bamboo poles one at each
corner. Closed meshed mosquito netting is preferred for that purpose,
as its meshes will allow a good circulation of water and will also not let
the laid eggs and milt escape through the meshes. The hapa measures
the range of 3m × 1.5m × 1m for breeders weighing to 3 to 5kgs. The
height of the hapa should remain about 20cm above to the level of
water. The roof can be open or closed. The roof can be opened or
The spawning takes place with in 3-6hrs following the second dose. It
turns out the midnight if the second injection was given in the evening.
Successful induced breeding results in the spawn of fertilized eggs. The
fertilized eggs are transparent, pearl like where as unfertilized eggs
are opaque or whitish.
FACTORS INFLUENCING THE
SPAWNING OF FISH:
Climate - 24°C to 31°C with cloudy days and
rainy periods. Light drizzling following heavy rains is
ideal. In absence of rain artificial showers are used.
Water – flowing water is preferred.
Turbidity – 100ppm 1000ppm.
Light – it is known to bring that light may help in
early maturation and spawning of fish.
SUBSTITUTES OF FISH
HCG (organon): When injected to L. Rohita @ 460-2010 IU/kg body
weight did not precipitate spawning. However it has been reported that L.
Rohita could be bred by injecting HCG @ 600 IU/kg body weight in a few
cases. In the case of silver carp, successful spawning could be achieved by
injecting HCG (organon) alone @ 630-660 IU and also with HCG 240 IU + 12
mg carp pituitary per kg body weight.
Synahorin: Along with carp pituitary gland was successful in breeding
rohu and silver carp, but failed to induce spawning when tried alone in rohu.
Ovaprim: It is the new inducing hormone for fish and absolute substitute
of pituitary extract though it’s costly. Ovaprim is far superior to carp pituitary
in inducing spawning in several species of carps.
1. The rates of fertilization and hatching were
generally higher in ovaprim treatment when
compared to pituitary.
2. The size of eggs after water hardening was
always considerably bigger in ovaprim treated
fish as compared to that of pituitary treatment.
This probably indicates complete development
3. The spawning response time was almost equal
in both ovaprim and pituitary treatments.
4. The hatchlings obtained from ovaprim
treatment appeared to be healthier than those
produced with pituitary. However, this aspect is
5. Based on the observations of the present
study, the dosage of ovaprim required for female
brood fish of various species is as follows:
• Catla _0.40 to 0.50 ml/kg
• Rohu_ 0.30 to 0.40 ml/kg
• Mrigal _0.25 to 0.30 ml/kg
• Silver carp_ 0.50 to 0.70
• Grass carp _0.50 to 0.70
• Big head carp _0.50 ml/kg
• Bata _0.50 mI/kg
• Fringe-lipped carp _0.50
6. Although the dosage required for males of various species
could not be standardised, it appears that males of most
species will respond to 0.10 to 0.20 ml/kg. On several
occasions, males could be induced with dosages of 0.10 to
7. The post-spawning mortality of ovaprim treated fish was
negligible due to relatively less handling in comparison to
8. Ovaprim does not require refrigerated storage and hence
can be preserved at ambient temperature.
PROBLEMS OF HYPOPHYSATION TECHNIQUE
Farmer cannot measure the potency of the available gland
Serious difficulties in large scale collection and storage of
Large gap between the supply and demand of pituitary
Basic equipment’s like chemical balance, centrifuge and
refrigerator normally not available in several farms
Pituitary gland very costly in market.
FISH HATCHERY OPERATORS SHOULD BE TRAINED ON BETTER BROOD FISH
MANAGEMENT, HATCHERY MANAGEMENT AND NURSERY MANAGEMENT TO
PRODUCE QUALITY FISH SEED.
GOVERNMENT OR FINANCIAL INSTITUTIONS SHOULD SPONSOR SETTING UP
OF FIELD LABORATORIES FOR ASSESSING AND MONITORING FISH SEED QUALITY.
MORE EMPHASIS SHOULD BE LAID ON MULTIPLE SPAWNING OF CARPS SO AS
TO ENSURE THE AVAILABILITY OF SEED OVER A LONGER DURATION IN A YEAR
GREATER SUPPORT (TECHNICAL AS WELL AS FINANCIAL) FROM GOVERNMENT
AGENCIES NEEDED FOR SUSTAINABLE FISH SEED PRODUCTION
PRODUCTION OF SEED OF VALUABLE SPECIES LIKE CATFISH AND MURRELS,
WHICH COMMAND A GOOD PRICE IN SEVERAL PARTS OF THE COUNTRY
THE GOVERNMENT OF INDIA SHOULD EXPLORE THE POSSIBILITY OF HAVING A
UNIFORM FISH SEED GRADING SYSTEM AND PRICING FOR THE ENTIRE COUNTRY