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 FisheriesN. D. U. A. T. Kumarganj Faizabad

A SEMINAR ON SEED PRODUCTION TECHNOLOGY OF

CAT FISHES (SINGHI AND MAGUR)

IndexIntroductionReproductive biology of Magur and SinghiHormone administration and induced

breeding.Preparation of sperm suspensionEgg collection by stripping the femaleFertilizationHatchery technologyBreeding technologyLarval rearingFeeding Advanced fry rearing

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.

Clarias batrachus (Magur)

Reproductive BiologyAge at first sexual maturity Sexualy Mature at one year age.Sexual dimorphismGenital 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.

Breeding technology

Maintenance of brood stockThey 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 .

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.

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.

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.

Stripping of female

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.

Hatchery technologyIncubation –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.

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.

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.

Rearing in nursery tanksRearing 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 .

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.

Hetropneustes fossilis (Singhi)

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.

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 orSalmon gonadotropin releasing hormone

analoge (SGnRH-A )500mg/kg body weight.Ovapirm 0.6 to 0.9 ml/kg. body weight .

Stripping the femaleThe 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.

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.

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.

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.

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.

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 .

Preparation of egg custardCollect 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.

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 .

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.com4. www.google.com

Thank You