INDUCED BREEDING TECHNIQUES

INFISHES

BYNEHA AGARWAL

BSC. HONS.

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 condition.

The stimulation promotes timely release of sperms and eggs from ripe gonads.

NEED OF INDUCED BREEDING

Because of environmental condition like photoperiod, rain, Temperature, currents of water.

Insufficient release of hormones in captive condition.

Insufficient of natural foods.

POINTS TO BE KEPT IN MIND

The brooders should be healthy, fully ripe and medium sized.

Large sized breeders are avoided for difficulty in handling.

Dose of the hormone should be calculated, according to given protocols

INDUCED BREEDING

INFISHES

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

As Hypophysation.

HISTORY OF INDUCED BREEDING

The technique of induced breeding was first evolved in Argentina after producing pituitary extract by B. A. Hussay in 1930.

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 IN CAPTIVITY??

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 MUCH TRAINING.

THE COST OF EXPENDITURE IS VERY LOW THAN THE NATURAL COLLECTIONS OF SPAWNS.

TECHNIQUESFOR

INDUCED BREEDINGInduced Breeding of Carps Monjit Paul, Mukti ChandaDepartment of Industrial Fish and Fisheries Asutosh College MAY 2014

(A). LOCATION OF PITUITARY GLAND:-

Pituitary gland is also known as Hypophysis.

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 Hypothalmus.

(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.

REMOVAL OF GLAND BY DISSECTING HEAD – 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.

INSTRUMENTS FOR GLAND EXTRACT PREPARATION- REMOVAL OF PITUITARY GLAND

I. ALCOHOL PRESERVATION: After collection glands immediately put in absolute alcohol for defatting and dehydrationAfter 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 doses1. Initial dose: 2-3mg/kg body weight.2. Resolving dose / final dose: 6-8mg/ body weight.-Male given only 1 dose at the time of the 2nd dose given to female (2-3 mg/kg body weight).-For females of indian major carps one

initial and after 5-6 hours final dose given.

INJECTION TO THE BROOD FISH

(G). SPAWNING

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

closed.

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

PITUITARY GLAND: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.

SYNTHETIC HORMONE OF FISH SPAWNING

OVAPRIM AND OVATIDE :-

OBSERVATIONS1. 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 of eggs.

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 being confirmed.

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 ml/kg • Grass carp _0.50 to 0.70 ml/kg • Big head carp _0.50 ml/kg • Bata _0.50 mI/kg • Fringe-lipped carp _0.50 ml/kg

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 0.15 ml/kg. 7. The post-spawning mortality of ovaprim treated fish was negligible due to relatively less handling in comparison to pituitary treatment. 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

pituitary

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.

CONCLUSIONFISH 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

Thank you!