Paiycuuæ En carp paæds
271
Tab£e
L FESH
SPECËES
WHECI—I ARE
USED
IN
POLYCUIÆURE
L Herbivorous
and
detrivorous;
Zoop1ankton and, benthos £eeders;
III..
Piscivorous…
-
‘
%
Species
Family
i.
Grass
carp
(Ctenopbaryngodon idella)
Cyprinîdae
Silver carp
(Hypophthalmiahtñys moiitrix)
“
.
Bighead carp (Aristâchîzhys nobis)
"
Mad carp
(Cirrhina molitorel1a)
"
—
Caüa
(Cade cada)
,.
Rohu
(Labeo rohita)
"
’
Mrigal (Cirrhinus mrigala)
"
Grey muilet (MugiI cephalus)
M‘ugî1idae
Ik-‘iuHét (Mugil capito)
"
_
Tilapia (Sarotherodon) aurea
Cichüdaè
Tilapia (Sarotherodon) gaüiaea
“
Tilapia €0reochromis)
mossambica
"
'
Tilapâa
Sarotherodon) nilotica
"
Tilapia‘ vulcani
_
'
"
Tilapia zilli
"
Il,
Common carp
(Cyprinus carpio
’
Cyprinidae
Black
carp
(Mylopharyngodon piceus)
"
Tench
(Tinca nes)
"
Crucian carp
(Carassius carassius)
"
Goidsh
(Carassius auratus)“
Golden ide
(Leuciscus idus)
"
Whitefish
(Coregonus Iavaretus)
Salmonidae
_
Peied
(Coregonus peled)
“
Sterlet
ruthenus)
Hester
?
Huso huso }:
3 A… ruthenus)
"
-
Paddlesh
(Polyodon spaüqula)
"
—
III.
Rainbow trout
(Saimo gairdneri)
Salmonîdae
Northern
pike (Essex lucius)
European c'atfish (Silurus glanis)
Siluridae
Pike »
(Lucioperca lucioperca)
Percidae
_
Largemouth bass (Micropterus salmoides)
_Centrarchïd_ae
Snakehead
(Ophiocephalus argus)
Ophiocephadae
For better understanding of the above question it seems neces—
sary to remind the rules which govern carp production in monoculture.
As
seen
in Figure 1, as stock density increases yield increases until
teaching the point of maximum possible yield M. After the l\__î3_Y_
is reached a further increase
of stock density causes yield to decre—
ase.
There£oré, from the ecological standpoint the true gain can
be
achieved under polycultural conditions when _1}_Ëj}_{_ of the carp in
polycuIture (CE) is equall or greater than that in
m0nocuIture
£MPY of Cgä—MPY of Cm).
‘
When
a
point of reference to the carp .MPY is not given,
it is
hard to say whether stocking of accompanyîng sn results
in
additional gain., Because if the c‘arp stocking density xs lower then
271
Tab£e
L FESH
SPECËES
WHECI—I ARE
USED
IN
POLYCUIÆURE
L Herbivorous
and
detrivorous;
Zoop1ankton and, benthos £eeders;
III..
Piscivorous…
-
‘
%
Species
Family
i.
Grass
carp
(Ctenopbaryngodon idella)
Cyprinîdae
Silver carp
(Hypophthalmiahtñys moiitrix)
“
.
Bighead carp (Aristâchîzhys nobis)
"
Mad carp
(Cirrhina molitorel1a)
"
—
Caüa
(Cade cada)
,.
Rohu
(Labeo rohita)
"
’
Mrigal (Cirrhinus mrigala)
"
Grey muilet (MugiI cephalus)
M‘ugî1idae
Ik-‘iuHét (Mugil capito)
"
_
Tilapia (Sarotherodon) aurea
Cichüdaè
Tilapia (Sarotherodon) gaüiaea
“
Tilapia €0reochromis)
mossambica
"
'
Tilapâa
Sarotherodon) nilotica
"
Tilapia‘ vulcani
_
'
"
Tilapia zilli
"
Il,
Common carp
(Cyprinus carpio
’
Cyprinidae
Black
carp
(Mylopharyngodon piceus)
"
Tench
(Tinca nes)
"
Crucian carp
(Carassius carassius)
"
Goidsh
(Carassius auratus)“
Golden ide
(Leuciscus idus)
"
Whitefish
(Coregonus Iavaretus)
Salmonidae
_
Peied
(Coregonus peled)
“
Sterlet
ruthenus)
Hester
?
Huso huso }:
3 A… ruthenus)
"
-
Paddlesh
(Polyodon spaüqula)
"
—
III.
Rainbow trout
(Saimo gairdneri)
Salmonîdae
Northern
pike (Essex lucius)
European c'atfish (Silurus glanis)
Siluridae
Pike »
(Lucioperca lucioperca)
Percidae
_
Largemouth bass (Micropterus salmoides)
_Centrarchïd_ae
Snakehead
(Ophiocephalus argus)
Ophiocephadae
For better understanding of the above question it seems neces—
sary to remind the rules which govern carp production in monoculture.
As
seen
in Figure 1, as stock density increases yield increases until
teaching the point of maximum possible yield M. After the l\__î3_Y_
is reached a further increase
of stock density causes yield to decre—
ase.
There£oré, from the ecological standpoint the true gain can
be
achieved under polycultural conditions when _1}_Ëj}_{_ of the carp in
polycuIture (CE) is equall or greater than that in
m0nocuIture
£MPY of Cgä—MPY of Cm).
‘
When
a
point of reference to the carp .MPY is not given,
it is
hard to say whether stocking of accompanyîng sn results
in
additional gain., Because if the c‘arp stocking density xs lower then