7. Control of Predatory and
Weed Fishes
The fishes which feed upon cultivable species of
hatchlings are called predatory fishes. Weed
carp
fishes
are
those
which
consumne
the aquatic
vegetations and thus, compete with the fishes
under cultivation. Important predatory and weed
fishes are listed in Table 5 and Figure 4. Certain
predatory fishes breed prior to the breeding of
19.
19.
P. conchonius
Mastocembelus amatus
20.
P. sophore
Nandus nandus
21.
Rasbora daniconius
22.
Notopterus chitala
23.
N. notopterus
22.
23.
Setipina phasa
Xenentodon cancila
19.
20.
Macrognathus
21.
24.
25.
26.
aculeatus
Pangassius pangassius
Pama pama
Pseudociana coitor
27.
Rita rita
28.
Silonia silondia
29.
Wallago attu
major carps in pond waters and go on feeding the
available planktons with fast increase in their
growth and size. When carp spawns are
introduced, the predators are large enough to feed
on
them. Weed fishes have relatively good
good
fecundity and attain sexual maturity in summer
and breed even without rain prior to the monsoon.
So their young ones are abundant in number
during monsoon.
Role of
predatory and weed fishes
ponds. Predatory piscivorous fishes feed on
in
the
culturable species as well as on the minnows.
Minnows being prolific breeders and
profuse
feeders on planktonic masses, consume almost all
natural fish food organisms and
occupy quite good
space in the pond
pond ecosystem.
these
Therefore,
(Z-56)
minnows
not
only
compete
for
food but also
compete for space with the culturable varieties of
fishes. This reason necessitates complete removal
in
or the control of
predatory and weed fishes
d
carp culture farm. Besides this, the stronger
canibalistic
larger sized predatory fishes show
and
behaviour and may feed on the weeker
smaller fishes. Hence, it is desirable to mpletely
eradicate the predatory and non predatory mla
from culturable
Secondly,
pond through management.
on
consumer's
the
than the
low
low
minnows and predatory fishes is very
ery
always
culture is
carp varieties. Therefore, carp culturc
preferable
over
the
predatory
preference
weed fish culture
and weed
i
am
Table 5.
Important predatory and weed flshe
Predatory flshes
Wecd flshes
Amphipnous cuchia
1.
Ambassis ranga
2.
Anabas testudineus
2.
Aplocheilus lineatum
3.
Ailia coila
3.
A. panchax
4.
A. berg
4.
Barilius bendelisis
Bagarius bagarius
B. bola
B. vagra
1.
6.
Clupisoma garua
5.
6.
7.
Clarias batrachus
7.
Chela cochins
8.
Channas striatus
8.
C. laubuca
9.
C. marulius
9.
Colisa fasicatus
10.
C. stewarti
10.
Changasius changasius
11.
C. punctatus
11.
Esomus danricus
12.
C. gachua
12.
Gudusia chapra
Eutripychthys vacha
13.
Gonialosa mannina
14.
Neomacheilus zonatus
Mystus seenghala
15.
16.
Osteobrama cotio
Oxygaster bacaila
17.
M. aor
17.
O. phulo
18.
M. cavasius
18.
Puntius ticto
19.
P. conchonius
20.
21.
P. sophore
Rasbora daniconius
22.
Setipina phasa
23.
Xenentodon cancila
13.
14. Glossogobius giuris
15. Heteropneustes fossilis
16.
19.
20.
Macrognathus aculeatus
Mastocembelus amatus
21.
Nandus nandus
22.
Notopterus chitala
23.
N. notopterus
24.
Pangassius pangassius
25. Pama pama
26.
Pseudociana coitor
27.
Rita rita
28.
Silonia silondia
29.
Wallago attu
Maintenance
Cpnstrucnon a n d M l a i
and
of Fish
[ 307
Farm
2
Anabas testudineus
Glossogobius giuris
AL
Esomus danricuss
Gadusia chapra
Ompok bimaculatus
Channa marulius
Laubuca laubuca
Oxygaster bacalia
RKESDEUC
LA
Mastacembalus armatus
Puntius spp.
Osteobrama cotio
Amblypharyngodon mola
T
,
Pangassius pangossius
Ambasis Spp.
Fig.
4. Predatory and weed fishes.
of
eradication of
to eradicate
methods may be applied
culturable fish
and weed fishes from the
ponds,
after
Netting operations.
small
water
method.
fish
origin.
Organophosphates.
Derris root
powder.
cane
(Saccharum
officina
jaggery
however,
the
biota.
phytoplanktons are no
Zooplanktons are killed a
cuchia etc. are killed by a dose of 6-10 mgl o
Derris powder. The requisite dose of 6-10 mgl
Derris powder mixed with water in a buckes
ines are used with live baits to catch such fishes.
Earthworms are used as baits in some cases.
Sprayed over the pond surface. This poison 15
Therefore,
more
care
toxicity
and
rearing ponds. The fish poisons are of three types :
precaution is essential in the selection of poison
and its application in culturable nurseries and
planktons also
are
mowrin
or
CSparin
or
even
e
"uhis
ingradiens
saponi
plant is used as fish poison. Its actuve
active
stocking of fingerlings ponds.
Bassica latifolia or Madhuca indica
commonly known as Mohua. Oil caxc
mona
Poisoning It is a sure method ofmuch effective in shallow water. The poisu
dys
effect of Derris root powder lasts for 41
eradicating the predatory and weed fishes from
when applied in a range of 4-20 mg/l. In or
any sized water body but its use has been kept
one
restricted because of highly toxic effect to various
avoid risk factor, it should be applied
useful aquatic biota. It produces
in
before
in
3. Hook and lines. Hooks and long lines are
beyond
applied to catech mostly the predatory fishes like
Wallago attu and murrels. Sometimes rods and
and
6 to 10 metres, it is more or
less insignificant. Majority of the weed fishes a
killed at 4 mg/l of Derris powder. Air breathing
fishes like murrels, climbing perches, mud et
to a large extent.
gradually
minnows
Dragnet may be
operated for effective removal of more numbers of
predatory and weed fishes.
successful removal of the predatory fishes and
on hot sunny days when the temperature is more
affected. It is effective upto a depth of 15 mere
once,
other aquatic
ultimately causes their death. It is also lethal to
the respiratory system of the unwanted fishes and
fish poison. It acts as a contact poison. It damages
rotinon (5%) is perhaps the m0st commonly used
Derris root powder containing ingradients
(6) Tamarindus indica.
(5) Sugar
(4 Bassica latifolia (Mahua oil cake).
(3)
(1) Crotton tiglium.
(2) Barring-tonia acutangula.
common plants are
of
such a
poisoning. Some uSed
barks, seeds, leaves, roots, etc. can
as the materials for fish
stem,
de
good
quite
for fish poisoning. Various parts of plants used
1. Fish poisons of plant origln. Thar
There
quite good number of plants
which mav
number of plants which
(3)
(2) Chlorinated hydrocarbons.
of plant
poisons
(1) Fish poisons
Types of
Fish Fam
than 25'C. In deeper water, its effect reduc
area with the help of a fine mesh dragnet ensures
a
sure
This method is rather
primitive one and not a very
However, by repeated netting in
2.
ponds
seasonal or short perennial nursery and rearing
minimum. This method is very
goes down to the
convenient and economically applied in the
suggested
remain alive
mud eel (Amphipnous cucbia) etc.
assists in
even deep in mud. Hence, desilting
is
removal of these fishes. Normally dewatering
water
in summer, when the depth of
ike murrels, catfishes,
desilting
species of fishes
climbing perch like Anabas,
silted
advisable. Certain
heavily
dewateringg is
n
pond
Complete
1.Dewatering and desilting.
soil
followed by drying of
dewatering of the pond
successful method in
bottom is suggested as a
This method is
eradication of unwanted fishes.
culturable ponds.
economical only in small
predatory
Following
flshes
predatory and weed
Methods
3081
Construction and Maintenance at
oll
effect
remains
ponds
at 1%
concentration may
for eradication of unwanted
Jaggary
in nursery ponds.
unwanted
of
and
acts
as
organo
of the
are
killed completely at concentration
aquatic
predatory and
as
endrin
formulated
detoxified by
s
devio
detoxification. Raw
algal
the
ponds having
rich
cow
dung @
18,000
rather quicker
blooms have
believed that
organic soil and
It
4-5 days.
@
acid
mg/l, sulphuric
formulated
ents
the endrin
applied in
detoxified within
pond will be
20-25
certain detoxifying
treated ponds, the
TCoalpowder
100 ppm, when
or
Demicals.
The endrin formulated chemical gives
taffdrin-20
gterm toxicity. For example, when
its toxicity
applied in low dose (0.008 mg/l),
wnen
But,
alon remains upto 15-20 days. deleterious
YDed in high dose (0.02 mg/l) its But the
40-45 days.
d ay prolong upto can be biotransformed
formulated chemicals
such as
of
8
and subaquatic fauna within
Biotransformation
nours.
lthe aquatic
ndrin
its effective poison. Taffdrin-20 at a low
dose of 0.008 mgl can kill minnows, weed fishes,
eC. The higher dose of taffdrin@ 0.02 mg/ may
the poison effect is over. Taffdrin contains 20%
days in 0.01 mg/l and for 2 days at 0.001 mg/l
oncentrati on. Planktons are also affected, specially
oplanktons but they may come up again after
0.2
0.01
mg/l, dialdrin
seedfishes. Aldrin
ngl and endrin
0.01 mg/l have been found
0
eiective in eradication of many unwanted species
Bo fishes. Their toxic effects remain for 12-15
pplied
for the eradication of
Dytiscus
(diving
beetles),
Gyrinus
Coleoptera includes Cybister (water
Thor
both larval and adult life
complete
due
to
their strong
cutting mandibles.
throughout in pond water. The death of the fry is
etc.
(whirling beetles), Hydrophilus (scavanger beetles),
beetles),
Order
Hemiptera.
more dangerous. They bear strong piercing type
mandibles and most fierce in praying upon fry.
Belostoma, Lithocerus (Giant water bug), Nepa,
(water scorpion), Ranatra (water stick insect),
Notonecta (Back swimmers), Geris (water spider)
etc., are other harmful insects belonging to order
Waterbugs of order Hemiptera are relatively
Fig. 5).
not compulsory.
Out of eleven orders of class insecta, three
orders namely Hemiptera, Coleoptera and Odonata
are relatively more common in freshwater ponds
in sizes, can not make any harm to rather bigger
sized fishes including fingerlings and yearlings.
Thus, eradication of insects in the stocking tank is
death of culturable tiny fishes. However, common
insects found in the culturable ponds being smaller
piercing, cutting and sucking type of mouth parts
of harmful aquatic insects cause direct or indirect
important role in increasing fry survival rate. The
aquatic insects is an essential requirement.
Eradication of harmful aquatic insects play an
8. Control of Aquatic Insects
insects.
ranging from 3-30 mg/. The dose of 0.032 to
0.5 mg/l is effective for the eradication of
fishes
dichloro-vnyl phosphate).
Laboratory experiment with above 3
organophosphates shows that most of the unwanted
CpHClO), endrin (C12HgCKO), and Taffdrin-20
aldrin (C12HgClg),
Following
detoxification
used in India to kill
of fishes and insects as
well.
(ii) Thiomatin, and (üi) DDVP
chiefly
unwanted species
) Phosphamidon
(0-0-dimethyl, 2-2,
are
Organophosphates.
phosphates
3.
in
water.
effective
For maintenance of fish farm, the eradication of
ike
is also
taffdrin treated pond
kg/ha
[309
dialdrin
bdrocarbons
2 Chlorinated hydrocarbons. Chlorinated
fishes
1750-2000 kg/ha for
used
be
kerilizer afterwards.
n also
adication
species
effective ingradient is saponin.
cies. The
eed meal of
of tamarind, Tamarindus indica
fish
arcane
Poisoning
a
of application. Hence, its
done atleast a month prior to
lost.
fect is
from the day
cake)
s
acts as
haemolysis
to fish
death. MOC
manure when its
to
causes
leads
it
mg/l
of Fish Fam
200-250
water
onsequently
should be
days
ASOnng
i
Juble in
application
s o l u b l e
B C
a n d
Being
Rended appliication is
is
Maintenance
the carp spawn
gadinga
Fos
and
n c h o na n d
.
8
4. Water boatman,
swimmer, 8. Damsel fly nymph.
3. Water scorpion,
6. Diving beetle, 7. Back
Spraying oil to kill the insects, wnc
5. Water tiger,
Fig. 5. Harmful aquatic insects of fish farm. 1. Cybister larva, 2. Water stick insect,
2
3
6
4
1 to 11
aquatic
hours. Pure gamaisomer of
benzene
hexachloride soluble in ethanol can kill
within
aquatic insects is obtained by
using insecticides. Gamaxene when
applied@
0.6-1 mg/l, can safely eradicate
aquatic insects
Effective control of
preda:ory aquatic insects
Eradication (control) of
been reported from
pon
controk
known
CIFRI
Teepo
insects. Chaterjee (1970)
Teepol B-300 in
substitution of soap by
has
recommended t
Cuttuck
to
principle and a routine practice in
a n d cheap
Emulsion of mustard or coconut ol
washing soap in the ratio of 56 18 kg/hec
malaria
up to the surface water to respire, is we
Dragon fly and dumsel fly are common 'insects within 6 hours at 0.01 mg/l concentralit
aquatic insects belonging to order Odonata. The The insecticides,
also affect advence
however,spawn.
Therefore, e
larval forms are aquatic while adult forms are
zooplankton and fish spawn. Therero may
terrestrial. Their nymphs are provided with sucking
insecticide should be of such type whi
ns.
type of mouth parts and cause death of culturable affect
only insects but not the zooplanko cOmE
fish fry.
T0.
Construction and
aintenance of Fish Farm
The recommended dose of
Teepol
560 ml. emulsified with 56 kg of mustrd oil.
mulsion.
emulsion.
is
of Govt. of Maharastra
has
dose of light speed diesel
oil
Fisheries Deptt.
recommended
a
(1 litre), hyoxid (0.75 ml) and water (40 ml) for
every 200 m2
m
of water surface for control of
of
aquatic 1nsects.
The use of diesel oil at 50 litre/hect. with 1/3
to 1/4 of washing soap can be applied to control
insects.
Kerosenne oil is also practiced among
pisciculturists for effective eradication of aquatic
insects. To kill water centipedes, quick lime can
be applied before fry stocking. A drug namely
dipterex crystal (concentration 90%) can be
Scattered into the entire pond in order to kill
aquatic centipedes in nursery ponds.