Fish Farming - An Introduction to Polyculture in Carp Varieties of Fishes

In our Agriculture for Everybody blog series,  we will be the seeing the basics of Fish Farming related to the Carp Varieties.

The entire blog will be presented in a Question & Answer format.  While it will be beneficial for the first time user to read the entire blog, the frequent users of this blog can just focus on their specific needs.

The following assumptions have been made and hence those will not be discussed here:-

• The soil has been tested for water holding capability
• The pH has been stabilised between 7.5 and 8.5 range
• The pond have been excavated
• The water is available throughout the year or at least for 6 months period

1. What is the minimum area required for fish farming?
• Even a Cent (435.6 Sq Ft) can be utilized for fish farming.  But, the more the better, as fishes tend grow well in large areas
2. What should be the shape of the pond?
• Even though any shape is okay, a rectangular shape is preferred for easy harvesting
3. What should be the direction of the pond?
• Other than Square or Round ponds, all the ponds should be in the East-to-West direction
• The basic requirement is that there should not be any shadow falling in the pond, as the shadow will minimize or reduce the growth of the natural feed in the pond
• Reason 1: For the growth of natural feed in the pond, the sun rays are required to fall in the pond and hence the pond should be excavated as explained above
4. What is the optimal depth of the water in the pond?
• Min : 3 ft of water depth
• Max : 5 ft of water depth
• Reason 1 : The sun rays will fall into the water up to a certain depth only and the sun rays are required for producing natural feed
• Reason 2 : During harvest, it will be easy for people to get into the pond and catch the fishes
5. How many ponds need to be created for fish farming?
   

   • It is always suggested to have multiple ponds
   • Reason 1 : You can grow different varieties of fishes in different ponds
   • Reason 2 : You can grow fishes of the same variety in multiple ponds but with varying ages for marketing purposes
6. How many fishes can be grown in 1 Acre?
• 3000 fishes can be grown in 1 Acre
7. What is the optimal size of fingerlings?
   • 3 to 5 inches or 10-15 cms size is suggested for fingerlings
   • Reason 1: For reducing the mortality of the fishes, it is suggested to buy reasonable size of fingerlings
   • Reason 2: Choosing a bigger size fingerling will help us to get multiple season harvest (Two Crops in One Year)
   
   
   
8. What are the varieties of Carps that can be grown in the same pond?

Catla	Zooplankton feeder	Surface feeder
Rohu	Omnivorous	Column feeder
Mrigal	Detritivorous	Bottom feeder
Silver Carp	Phytoplankton feeder	Surface feeder
Grass Carp	Herbivorous	Surface, column & marginal areas
Common Carp	Detritivorous/Omnivorous	Bottom feeder



9. What is the suggested % of Carp varieties in the same pond?
• The following % of carp varieties should be kept as a guideline and can be changed based on the local requirements and needs

Species	3-species	4-species	6-species
Catla	4.0	3.0	1.5
Rohu	3.0	3.0	2.0
Mrigal	3.0	2.0	1.5
Silver Carp	-	-	1.5
Grass Carp	-	-	1.5
Common Carp	-	2.0	2.0








10. What is the need for growing polyculture fish instead of monoculture fish in the same pond? 
    • Instead of growing monoculture fish in a pond, it is suggested to grow polyculture fish for the reasons given below.
    • Reason 1: If we grow a single variety of fish, it will feed only on a specific variety of organism and also utilize only a portion of the pond.
    • Reason 2: If we grow multiple varieties of fishes, the different varieties of the carps feed on the different organisms which grow in different depth of the pond and hence utilization of the available infrastructure is maximized
11. What is the period of availability of fingerlings?
• The fingerlings are available during Jul-Jan period
12. What is the optimal time to stock the fingerlings?
• Nov or Oct is the best time to stock the fingerlings in the pond
13. What is the right time to release the fingerlings in the pond?
    

    • Should be done After sunrise or Before sunset
    • Early mornings or Late evenings is a better option
    • Reason 1: The temperature of the water should be (made) equivalent to the temperate in the plastic bag which contains the fingerlings
14. What is the initial manures that need to be put before introducing the fingerlings?
    

    • Initially, 1000 Kgs of Fresh Cow Dung or equivalent should be put in to enable natural feed to grow for 1 Acre.
15. What is the optimal time to introduce the fingerlings in the ponds?
• Before introducing the fingerlings in the pond, the pond should have enough feed for the fingerlings.  The best indication is a thin layer of light green floating in the surface of the water.  It takes 15 days (for the first time) to grow.
16. What are the different types of feed that can be given to the Carps?
• The following are some of the feeds that can be provided to the Carp fishes:-
• Fresh Cow Dung (3-5 Cows Required per Acre)
• Fresh Goat Manure
• Fresh Chicken Manure (70-100 Country Chickens Required per Acre)
• Fresh Pig Manure (12 Pigs Required per Acre)
• Fresh Duck Manure (100 Ducks Required per Acre)
• Compost
• Daily Cleaning Water of Shed (Dairy)
• Groundnut Cake
• Coconut Cake
• Rice Bran
• Wheat Husk
• Tender Banana Leaves
• Indian Coral Tree (Kalyana Murungai)
• Sesbania grandiflora (Agathi)
• Subabul
• Andrographis paniculata (Siriya Nangai)
• Holy Basil (Tulsi)
• Azolla
• Glyricidia
• Thespesia Populnea
• Leafy Vegetables (Grass Carp Only)
• CO4 (Grass Carp Only)
• Guinea Grass (Grass Carp Only)
• Velam Paasi (Grass Carp Only)
• Napier Grass (Grass Carp Only)
• Alfalfa (Kuthirai Masal) (Grass Carp Only)
17. When to feed?
• The feed should be provided to the fishes at the same time everyday
18. Where to feed?
• The feed should be provided to the fishes at the same place everyday
  
19. How much to feed?
• Usually, the following can be used as a general rule
• Number of Fishes X Weight of Fish in Gms/100 = Quantity of Feed in Gms
20. How many times to feed?
• It is preferred to feed daily once or at the most twice in a day
21. What time to feed?
• It is suggested to feed in the early mornings
22. What is the Avg weight of fishes in 1 Yr period?
     

    Catla	1-1.5 Kgs
    Rohu	1 Kg
    Mrigal	1 Kg
    Silver Carp	1 Kg
    Grass Carp	1 Kg
    Common Carp	1 Kg


23. What is the harvest period?
• Starting from the 6th month onwards, the harvest can begin and the harvest needs to be completed by 1 year 
• Reason 1: The growth rate is very fast during the first 6 months and will reach its maximum (fast) growth by 1 year 
• Reason 2: The growth rate from the 2nd year will be very slow
24. What is the expected harvest in Kgs?
• 1500 Kgs to 1750 Kgs is the expected harvest per year for 1 Acre
25. What is the right time to release the fingerlings in the pond?
• Late evenings is a better option
• Reason 1: The temperature of the water should be (made) equivalent to the temperate in the plastic bag which contains the fingerlings
26. What are the materials that are required for fish farming?
• Drag Net 
• Fish Net for capturing few fishes for weighing purposes 
• Weighing Machine
27. What are the diseases that may occur in fish farming?
• Generally, the diseases wont occur if we maintain the stock density properly and the water quality in the right way

References : TNAU & Others



For gaining more information on Fish Farming, the following can be of great use to the readers.

1. http://www.fao.org/docrep/t0581e/T0581E00.htm#Contents
2. http://journeytoforever.org/farm_library/agrodok.html (Small-scale freshwater fish farming & On-farm fish culture)