Nursery Pond management of Fish or shrimp

1. NURSERY POND MANAGEMENT
By
Dr. K. Narasimha Murty

2. Introduction
 Different types of ponds are required for the culture
 They are nursery, rearing and production or stocking ponds
 According to Alikunhi, under Indian conditions, 4 hec., fish farm
should have the following ratio
Nursery pond : 0.2 hec.
Rearing pond : 0.8 hac.
Stocking pond : 3.0 hac

3. Nursery Ponds (NP)
 These are smallest of the fish ponds measures about 0.02-0.06 hact.,
and 1 met in depth.
 These are meant for nursing the hatchlings/spawn (5-6 mm) for a
period of 15 to 30 days until they become fry (2.5-3.0 cm).
 In practice about 10 million spawn per hect., are stocked in NP.
 The NPs may be earthern or constructed with brick and cement.

4. Rearing Ponds (RP)
 These are slightly larger than the NPs.
 Usually measure about 0.08-0.1 hact.,
 Depth of the RPs 1.0-1.5 m.
 In RPs, the fry are grown for about 2 to 3 months until they
become (fingerlings 8-12 cm).

5. Stocking Ponds (SP)
 SPs are also called Production ponds or Grow-out ponds.
 These are the largest among other ponds in a farm.
 Size of SPs 0.4-40 hact., or more but the ideal size for efficient
management is 2 to 4 hact.,
 Depth of water in these ponds 1.5-3 m.
 In these ponds, the fingerlings and advanced fingerlings or juveniles
are reared upto marketable size for about 6 months to one year.
 The economic size of the ponds depends on the ecological conditions
of the area and the type of fish culture.

6. Stocking Ponds (SP)

7. Nursery Pond Management
The nursery pond management includes pre-stocking, stocking and
post stocking management.
A. PRE-STOCKING MANAGEMENT
i) Dewatering and drying
ii) Desilting
iii) Control of predatory and weed fishes
iv) Control of Aquatic weeds
v) Liming
vi) Watering
vii) Fertilization or Manuring
viii)Control of Algal blooms
ix) Control of Aquatic insects
x) Water quality

8. i) Dewatering and drying
 First water is removed from the ponds and exposed for sun
drying.
 Drying of ponds in summer helps in the mineralization of soil,
removal of organic detritus, and automic destruction of
pathogens, aquatic weeds, predatory and unwanted fishes.
ii) Desilting
 The silt with rich humus or excess organic matter at the
bottom is removed and this can be used to fill the sides and for
strengthening the bunds.

9. iii) Control of predatory and weed Fishes
 The common predatory fishes are Channa spp., Wallago attu,
Clarias batrachus etc.,
 These cause heavy mortality of spawn as they feed on spawn.
 The common weed fishes are Puntius, Barilius etc.,
 The weed fishes are not predatory but they complete for food
and space with the culture fish.
 They must be eradicated from the nursery pond either by
netting or by poisoning.

10. Clarias batrachus
Puntius

11. Treatment of Predatory and Weed fishes
 Chlorinated hydrocarbons and organophosphates
 Derris root powder : 5 ppm
Mahua oil cake : 200 ppm
Tea seed cake :75-100 ppm
Chlorinated hydrocarbons (Aldrin) : 0.2ppm
Dieldrin : 0.01 ppm
Endrin : 0.001 ppm
Organophosphates, nuvan (DDVP) : 2-20 ppm

12. iv) Control of Aquatic Weeds
Aquatic weeds affect the fish culture by
 Limiting the space for movement
 Competing with phytoplankton by absorbing nutrients
 Causing imbalance in the DO concentration
 Causing siltation
 Hampering netting operations and harboring unwanted
fishes, insects and molluscs

13. Aquatic weeds
Algal weeds : Spirogyra, Chara
Floating weeds : Eichhornia, Lemna and Pistia
Emergent : Nymphaea, Typha
Submerged : Vallisneria, Hydrilla and Utricularia
Marginal : Marsilia, Ipomoea

14. Algal weeds
Spirogyra

15. Ipomoea
VallisneriaNymphaeaPistia

17. Control of Aquatic Weeds
 Use mechanical, chemical and biological methods
 Mechanical method includes collection and disposal of the
weeds by cutting, dragging, ploughing etc.,
 Chemical method involves spraying of chemicals such as
Simazine : 5 kg/ha
Ammonia : 15 ppm
80% 2-4D : 5-7 kg/ha
(2-4 dichlorophenoxy acetic acid) for floating weeds
Emergent weeds: Dichlorophenyl : 10 kg/ha or
fenate (2,3,6 trichlorophenyl acetic acid)

19.  Submerged weeds
Ammonia : 15 ppm
Simazine : 3-5 ppm
Fenate : 10 kg/ha
 Marginal weeds
Dichloropheynl : 10 kg/ha
Diquats : 1 kg/hac

20. Biological methods
 Introducing the Grass carp and common carp that feed on
most of the weeds except Salyina and Eichhornia.
v) Liming
 This is the first step in the fertilization of a nursery pond.
 Liming is most essential to maintain the pH of water.
 Range of 7.5-8.5
 It helps to eradicate the harmful bacteria and fish parasites.
Common carp, Cyprinus carpio

22. pH of soil Soil condition Dose of lime;
Kg/ha
4.0-4.5 Highly acidic 1000
4.5-5.5 Medium 700
5.5-6.5 Slightly 500
6.5-7.5 Near neutral 200

23. vi) Watering
 To avoid the entry of exogenous fish into the pond,
Eg. Unwanted eggs, young or adult stages
vii) Fertilization
 Fertilization has to be done after filling the pond with water.
 The main aim of fertilization of water is the production of
adequate of quantities of plankton, natural food of carp
spawn.

24.  Fertilizers used in ponds are of two types
1. Organic manures
2. Inorganic manures
Super phosphate : 250 kg/ha
DAP : 80-100 kg/ha
GOC : 250 kg/ha

25. viii) Control of algal blooms
 Algal blooms are invariably caused by unicellular and
filamentous algae which impact green, reddish-brown and
bluish-green colouration to the water.
 Eg. Euglena, Volvax, Prdidinium, BGA
 Controlled by the 1 ppm copper sulphate, 05 ppm simazine

26. ix) Control of aquatic insects
 After watering and fertilization, predatory aquatic insects
may sometimes develop enormously.
 Hemiptera and Coleoptera
 Water strider, back swimmers, water scorpions
 Diving b beetles (Cybister); whirligig beetle (Dineutes)
 The oil emulsion with 60 kg of oil and 20 kg soap are
suffecient to treat 1 hac of water.
 Dieldrin 0.5 ppm, benzene hexachloride 0.1 ppm

27. Orders you may encounter Ephemeroptera (mayflies)
Eggs – larva – subimage - adult
Larva – elongate, 3 filaments (tail), can have 2
Lamellate gills along abdomen
Well developed legs
Perpendicular wings on adults

28. Plecoptera (stoneflies)
•Same life cycle as mayflies
•Have 2 filaments
•No lamellate gills along abdomen
•Some have filamentous gills
•Adult wings are flat
•Mostly shredders and grazers

29. Odonata (dragonflies, damselflies)
•Eggs –larva –teneral adult - adult
•Predacious
•No external gills
•Longer body on damselflies (wings up)
•Dragonflies (wings down)

30. Diptera (midges, mosquitoes, gnats, flies)
•Elongate body
•Segmented body
•Most species rich order (includes Chironomidae)
•Adults have one pair of wings
•Very diverse morphology

31. Hemiptera (true bugs)
•Egg – nymph larva –adult
•Predacious “beak”
•Wing pads
•If wings develop they fold over each
other

32. Coleoptera (beetles)
•Egg – larva –pupa – adult
•Larva very different from adult
•Adults – have hard case on body that does not
overlap
•Adults have chewing mouthparts
•Larva –undeveloped eyes, sometimes have tusks

33. Megaloptera (alder flies, dobsonflies)
• Mouth has large, chewing pinchers (predacious)
• Abdomen has strand-like appendages extending from each side
• Three pairs of segmented legs on middle section of body
with tiny pinchers at the end of each
• Each segment contains filaments for respiration
• Abdomen ends with two elongated appendages or prolegs

34. x) Water quality
 Brown colour of water indicates rich zooplankton.
 Green or blue colour indicates dominace of algae in the
plankton.
Range of some of the chemical parameters
DO : 5 – 8 ppm
pH : 7.5 – 8.5
CO2 : <15 ppm
NH3 : <0.5 ppm
PO4 : 1.0- 20 ppm
NO3 : 1 ppm

35. B. Stocking
 Nursery ponds generally stocked at the rate of 5-6 million
spawn/ha.
C. Post-stocking Management
Feeding:
 After stocking, the spawn start feeding voraciously on the
plankton.
 Survival and growth of spawn are influenced mostly by
the quantity and quality of food available in the pond.
Artificial food is necessary.
The feeding schedule is as follows
2-5 days - double the initial body weight of the spawn stocked
6-10 days - thrice the initial body weight of spawn stocked
11-15 days - four times the initial body weight of the spawn stocked

36. D) Harvesting of fry
 In 15 days of nursery rearing, the spawn grows to a
size of 20-25 mm fry.
 At this stage, the fry could b e harvested and
transferred to rearing ponds.
 Supplementary feeding should be stopped a day before
harvesting.
 Using 1/16” mesh drag net.
 Survival rate would be 60-80%

37. Thank you