This document summarizes the seminar on seed production technology for two species of catfish, Magur and Singhi. It discusses the reproductive biology of both species, covering topics such as breeding season, sexual dimorphism, and fecundity. It also provides details on hormone administration, spawning induction, egg and sperm collection, fertilization, hatchery protocols, larval and fry rearing practices, and feeding trials. The document aims to inform readers on the complete seed production process for these two economically important catfish species.

1. A SEMINAR ON SEED PRODUCTION
TECHNOLOGY OF CAT FISHES
(SINGHI AND MAGUR)
Instructors – Dr. A. P. Rao
Dr. S. Khan
Dr. S. P. Singh
Dr. N. P. Tewari
Dr. L. Prasad
Topic Related Instructor – Dr. L. Prasad
Name – NARENDRA KUMAR
B. F. Sc. IVth year
I.D.NO. F-4314/08
College of Fisheries
N. D. U. A. T. Kumarganj Faizabad

2. Index
Introduction
Reproductive biology of Magur and Singhi
Hormone administration and induced breeding.
Preparation of sperm suspension
Egg collection by stripping the female
Fertilization
Hatchery technology
Breeding technology
Larval rearing
Feeding
Advanced fry rearing

3. Introduction
The asian cat fish Clarias batrachus locally known as Magur.
There are three cultivable species Clarias batrachus, C. gariepinus
C. macrocepalus.
In natural waters the fish spawn during rainy season in Assam
June –August .
C. batrachus is widely distributed in India, Ceylon, Bangaladesh,
Pakistan and Thailand etc.
The Paddy fields which are main breeding grounds of this fish.

4. Clarias batrachus
(Magur)

5. Reproductive Biology
Age at first sexual maturity
Sexualy Mature at one year age.
Sexual dimorphism
Genital papilla in male is long and pointed.
It is round or oval, button shaped the vent in the mature
female is reddish but bulging in male it is slender and whitish.
Breeding season
It breeds only once in a year from June-August.
Peak period being July.
fecundity .
Very low in the range of 1500 to 20000.

6. Breeding technology
Maintenance of brood stock
They are to be stocked in stocking tanks cement cistern.
Female with soft bulging abdomen are selected and sample of
eggs can be collected using a catheter.
Usually selected breeders are kept starved at least for one day
to injecting hormone. This will help in keeping the
alimentary canal empty at the time of stripping.
Parental care-
The female lay eggs in pits made along the margin of water
body .
Soon after yolk sac absorption fry start moving around
feeding zooplankton .

7. Hormone Administration in
induced breeding
Crude pituitary gland extract.CPGE
 A single dose of carp pituitary 30 g./kg. body weight is found
effective in inducing clarias to spawn.
 Ovaprim.
 The synthetic hormone preparation from Syndel laboratories
Canada 0.4 ml/kg. has been found very effective in this body.

8. Preparation of sperm
suspension
Collection of milt is done by grinding the testes in 0.9 percent
saline after sacrificing the mature male.
Sacrifice a male fish by decapitation and remove the testis.
Cut the testis into pieces by a fine scissor and crush it with
pestle.

9. Egg collection by stripping the
female
Stripping the female is done about 14 to 15 hours after the injection of
CPGE/Ovaprim at 27C to 30C.
Fully mature eggs look dark brown or brownish green in colour.
The stripped fish is bathed for 2to3 minutes in potassium permangnate
solution after which it is released in to stocking tank.

10. Stripping of female

11. Fertilization
The sperms fertilize the eggs.
Remove pieces of testis or any tissue from among the eggs.
The fertilized eggs are now transferred to trays for incubation.

12. Hatchery technology
Incubation –
The fertilized eggs are Demersal, adhesive and spherical.
The eggs are also treated with malachite green as a prophylactic measure
before placing the same in flow through for incubation.
Development and hatching-
The fertilized eggs undergo development and young hatches out with 25-26
hours at 27C-30C.
The newly hatched larva measures 4-5 mm. and weight 2.8to 3.2mg.
The larva usually rests at the bottom and yolk sac gets absorbed it moves in
the water and starts feeding.
Larval rearing-
The spawn can be reared in a shallow container for 10to12 days.
The larvae should be stocked at a density of 2000to4000 per square meter.
The water quality maintain to DO. 4.0ppm. To saturation water
temperature 26-31C., PH 7-8.5.

13. Feeding
Feeding has to be started on the 4th day.
Artemia nauplii is to be fed adlibitum for one week to ten days.
In addition to the artemia nauplii zooplankters like cladocerans,
moina are also preferred by Clarias fry.

14. Advanced fry rearing
10-12 days old fry can be shifted to a larger containers and
stocked 1000 fry /sq. m.
If rearing is continued in the above containars their growth is
found slowing down .
Hence the fry at this stage (20-24 days) released into nursery
tank.

15. Rearing in nursery tanks
Rearing tanks shall be of small size 50 sq.m. having sides
cemented.
The fry can be stocked 100-200/sqm. and reared for another 15
days.
Feeding can done with finely minced trash fishes or molluscan
meat and rice bran 1:1 daily in the evening hours .

16. Hetropneustes fossilis (Singhi)
Introduction
Heteropneustes fossilis is commonly known as Singhi or stinging cat
fishes which was a great potential as a candidate species for
aquaculture.
The presence of accessory respiratory organ helps thrive well in
shallow and derelict water with poor oxygen .
It also compatible with the carps in mixed culture.

17. Hetropneustes fossilis (Singhi)

18. Reproductive Biology
Age and size at first maturity-
 It attains first sexual maturity when one year old reaching 8-12 cm. length.
Sexual dimorphism –
 The male and female distinguished from each other only during breeding season.
 The female genital papilla is more prominent round.
 But male genital papilla is pointed.
Breeding season –
 It is breeds confined water during monsoon months between June and august peak
being July.
Fecundity-
 It is fecundity has been estimated at 1500-2000 eggs per gram ovary.

19. Seed production
Brood stock maintenance-
Adult brood fishes weighting 50-100g. Can be procured
from natural waters and reared in cement cisterns.
 Stocking density can be about 10-12 fish per cubic meter
Feeding can be done with molluscan meat or formulated
feed containing rice bran and fish meal.
Injection of hormones –
A female is a administered either pituitary gland extract 15-
20 mg/kg. body weight or
Salmon gonadotropin releasing hormone analoge (SGnRH-A
)500mg/kg body weight.
Ovapirm 0.6 to 0.9 ml/kg. body weight .

20. Stripping the female
The female is stripped 14 to 18 hours after hormone injection
The female wiped with the wet clothes and the readiness of the
female is tested by gently pressing the belly.
The eggs are then counted either by gravimetric or volumetric
method.

21. Preparation of sperm
suspension
The male brood fish is cut upon and testis are dissected out into a
mortar and cut into pieces in 0.6 % saline and crusted using a
pestle .
Just prior to stripping the female.

22. Fertilization
Usually the fertilized eggs are greenish blue in color and settle to
the bottom .
The unfertilized eggs are somewhat white and found floating.
The fertilized eggs are moderately adhesive.

23. Incubation of fertilized eggs
The newly hatched larvae measures 2.72 mm. in length having a
round yolk sac which forms almost 42% of the total length .
It is transparent having a laterally compressed body.
They remain at the bottom resting on their sides.

24. Rearing of fry -
Fifth day after hatching yolk sac is fully absorbed.
Tenth day it measures 7.5 mm. in length.
Care is taken to rear the spawn in shallow containers at density
of 3000 to 5000 sq.mt.

25. Feeding
The larvae stared feeding they are given adequate quantity of
live feed .
The live rotifers and ciliates 3 to 10 days .
In addition custard and mollusc an meat for the fry .

26. Preparation of egg custard
Collect the egg content (white along with yellow )and mix equal
quantity of milk powder .
Add 0.5 g vitamin, mineral piece mix and make a homogenate.

27. Rearing of advanced fry -
The transferred of old fry 10-12 day to large cement cistern or
plastic pool containing 15cm deep water .
Stocking rate can be 3000-5000 fry per sq. m.
Before releasing the water is aerated.
The fingerling can be marketed for rearing in grow out pond .

28. Reference
1. Breeding and seed production of fin fish and shell fish. P.C.
Thomas,page no.106-122
2. Handbook of Fisheries and aquaculture page no.283- S.
Ayyappan
3. www.wikkipedia.com
4. www.google.com

29. Thank You