836
V.G. Jhingran
INTRODUCTION
Polyculture of major Indian carps catla Catla catla, rohu Labeo rohita,
mrigal Cirrhinus mrigala, and calbasu Labeo calbasu has been traditionally
practiced in fresh water ponds and tanks of India, especially in the Indian
state
of West Bengal, from ancient times. A three pond system viz.nursery,
rearing and stock ponds still continues. The first two set of ponds rear fish
seed from larvae to fry, and fry to fingerling stages respectively and in the
last
(stock ponds), fingerlings are grown to table—sized fish. Until artifi—
cial fish breeding by hypophysation was developed in India in 1957, rivers in
the fluviatile environment of which, major Indian carps naturelly breed during
South—West monsoon
(June—September in North India) and North—East monsoon
(October—January in South India), formed the common source of the generally
mixed
seed—fish af all the four species. Despite the scope for monoculture of
fish of
specific purity having been enhanced with the advent of hypophysati0n,
polyculture of all the species of major Indian carpe continues to be practiced
in India for good reason, which is that the four species occupy some of the
major naturally occurring ecological niches of the waterbody viz° 200plankton
held by catla, periphyton by rohu, and detritus by mrigal and calbasu respec—
tively. Polyculture gives a higher per hectare per year quantum of yield than
what would perhaps otherwise be possible through monoculture especially in the
absence of artificial feeding. With the introduction of common carp, Cyprinus
carpio in India in 1939 and of grass carp Ctenopharyngodon idella and silver
carp,
Hypophthalmiehthys molitrix, both in 1959, the scope for filling
hitherto unutilized ecological niches viz. deeper lying detritus obtainable by
burrowing pond embankments and bottom, macro—vegetation and phyt0plankton by
the three species respectively, opened up. With these introductions a form of
polyculture of selected major indian carpe and selected chinese carpe, called
composite fishculture has begun and is increasingly being practiced in India.
Productivity of all the three ponds is sought to be enhanced by fertilization
and fish yields further raised by artificial feeding.
I.
PROCUREMENT OF STOCKING MATERIAL
The stocking material of the major Indian carps comprises the eggs, post—
larvae, fry and fingerlings. These are obtainable by: 1) collecting eggs from
natural riverine breeding grounds; 2) collecting postlarvae, fry and finger—
lings
from the streams and rivers; 3) breeding fish naturally in special
Bundh—type—tanks", and 4) inducing carps to breed by hormonal injections. For
breeding fish in "Bundh—type—tanks", in which no recourse to hypophysation is
traditionnaly done, riverine fluviatile conditions are stimulated in especial—
ly constructed enclosures situated in the slope of a generally vast catchment
area
providing an inlet and an outlet. In this system, brood fish aïe intro—
duced at an opportune moment from an extraneous source.
In recent
years,
however, a practice has been developed in which 10—20 % of brood stock intro—
duced for Spawning is injected intramuscularly with carp pituitary extract at
an appr0priate
time which results generally in synchronous spawnig of the en—
tire
introduced
brood stock. For induced breeding by hypophysation in which
the Indian major carps are bred individually, a system of two intramuscular
injections
of
carp pituitary extract has been evolved. The first, a stimulatiûê
or
primary dose, consists of & preliminary dose of 2—4 mg of carp pituitary
extract
per kg Of b0dÿ weight Of the recipient female followed six hours later,
by a second dose,
called the resolving dose, of 8—12 mg/kg body weight. FOI
.
of
……
..
generally take
lacÊnäeîtloîlto
female
Spawning and fertilizatiOû
pituitary extraît Theaturâ
Within SlX hours
of
the second injection of
India is about the
same
ec
nlque of breeding Silver carp and grass carp in
as
that adopted for the Indian major carpe having been
V.G. Jhingran
INTRODUCTION
Polyculture of major Indian carps catla Catla catla, rohu Labeo rohita,
mrigal Cirrhinus mrigala, and calbasu Labeo calbasu has been traditionally
practiced in fresh water ponds and tanks of India, especially in the Indian
state
of West Bengal, from ancient times. A three pond system viz.nursery,
rearing and stock ponds still continues. The first two set of ponds rear fish
seed from larvae to fry, and fry to fingerling stages respectively and in the
last
(stock ponds), fingerlings are grown to table—sized fish. Until artifi—
cial fish breeding by hypophysation was developed in India in 1957, rivers in
the fluviatile environment of which, major Indian carps naturelly breed during
South—West monsoon
(June—September in North India) and North—East monsoon
(October—January in South India), formed the common source of the generally
mixed
seed—fish af all the four species. Despite the scope for monoculture of
fish of
specific purity having been enhanced with the advent of hypophysati0n,
polyculture of all the species of major Indian carpe continues to be practiced
in India for good reason, which is that the four species occupy some of the
major naturally occurring ecological niches of the waterbody viz° 200plankton
held by catla, periphyton by rohu, and detritus by mrigal and calbasu respec—
tively. Polyculture gives a higher per hectare per year quantum of yield than
what would perhaps otherwise be possible through monoculture especially in the
absence of artificial feeding. With the introduction of common carp, Cyprinus
carpio in India in 1939 and of grass carp Ctenopharyngodon idella and silver
carp,
Hypophthalmiehthys molitrix, both in 1959, the scope for filling
hitherto unutilized ecological niches viz. deeper lying detritus obtainable by
burrowing pond embankments and bottom, macro—vegetation and phyt0plankton by
the three species respectively, opened up. With these introductions a form of
polyculture of selected major indian carpe and selected chinese carpe, called
composite fishculture has begun and is increasingly being practiced in India.
Productivity of all the three ponds is sought to be enhanced by fertilization
and fish yields further raised by artificial feeding.
I.
PROCUREMENT OF STOCKING MATERIAL
The stocking material of the major Indian carps comprises the eggs, post—
larvae, fry and fingerlings. These are obtainable by: 1) collecting eggs from
natural riverine breeding grounds; 2) collecting postlarvae, fry and finger—
lings
from the streams and rivers; 3) breeding fish naturally in special
Bundh—type—tanks", and 4) inducing carps to breed by hormonal injections. For
breeding fish in "Bundh—type—tanks", in which no recourse to hypophysation is
traditionnaly done, riverine fluviatile conditions are stimulated in especial—
ly constructed enclosures situated in the slope of a generally vast catchment
area
providing an inlet and an outlet. In this system, brood fish aïe intro—
duced at an opportune moment from an extraneous source.
In recent
years,
however, a practice has been developed in which 10—20 % of brood stock intro—
duced for Spawning is injected intramuscularly with carp pituitary extract at
an appr0priate
time which results generally in synchronous spawnig of the en—
tire
introduced
brood stock. For induced breeding by hypophysation in which
the Indian major carps are bred individually, a system of two intramuscular
injections
of
carp pituitary extract has been evolved. The first, a stimulatiûê
or
primary dose, consists of & preliminary dose of 2—4 mg of carp pituitary
extract
per kg Of b0dÿ weight Of the recipient female followed six hours later,
by a second dose,
called the resolving dose, of 8—12 mg/kg body weight. FOI
.
of
……
..
generally take
lacÊnäeîtloîlto
female
Spawning and fertilizatiOû
pituitary extraît Theaturâ
Within SlX hours
of
the second injection of
India is about the
same
ec
nlque of breeding Silver carp and grass carp in
as
that adopted for the Indian major carpe having been