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Hapa Nets for Fingerling

Hapa Nets for Mass Fingerling Hatchery Production

The "Hapa Nets for Mass Fingerling Hatchery Production" technology i a cage-like enclosures (referred to as "hapa" nets) placed within ponds to safeguard and manage brooders, hatchlings, and juvenile fish. The hapa nets come in various shapes and sizes, using materials like wooden poles and mesh nets, offering an affordable solution for hatcheries of all sizes. The nets require periodic maintenance to ensure effective functionality, but they significantly improve the management and production of fingerlings for the aquaculture industry. These nets are designed to shield fish from predators, ensuring better control over breeding, feeding, and aeration. They provide a conducive environment for fish growth, resulting in enhanced fertilization rates, reduced mortality, and increased production of fry and fingerlings. This technology is well-suited for various aquaculture species and adaptable to different water bodies such as earthen ponds, riverbeds, or concrete tanks.


This technology is TAAT1 validated.


Scaling readiness: idea maturity 8/9; level of use 8/9

Cost: $$$ 1 USD

Per square meter

150—900 fingerlings per square meter

Production in hapa

8—20 fish farmers

Number of fish farmers in a single hatchery


Open source / open access


  • Inadequate supply of high-grade fingerlings from improved fish breeds
  • Poor and uneven growth rates
  • High fingerling mortality in open ponds
  • Predation by birds, reptiles, amphibians, and aquatic insects
  • Need for rapid and uniform production of fish stock
  • Difficulty in monitoring and managing brooders, hatchlings, and juveniles
  • Aggressiveness among fish during spawning leading to injury and mortality
  • Degradation of net materials in sunlight requiring periodic replacement
  • Damage from storms, winds, or heavy rainfall
  • Clogging of hapa mesh limiting water circulation and aeration
  • Poor water quality within the net without adequate circulation
  • Need for complete feeding regimes within the enclosure and adjustment during different growth stages
  • Scrubbing of hapa nets to prevent clogging and maintain water circulation
  • Accumulation of uneaten feed and fish waste resulting in poor water quality
  • Cleaning of dirty hapa nets with urea and scrubbing with a brush
  • Monitoring and recording of fry and fingerlings harvested from individual hapa for rearing efficiency optimization.


  • Provides a convenient means of safeguarding brooders, hatchlings, and juveniles from predators and other fish.
  • Eases the management of brooder, fry, and fingerlings, allowing for closer monitoring and adjustment of breeding, feeding, or aeration regimes.
  • Enables higher fertilization rates, even growth of fish seed, and reduced mortality, resulting in increased production of fry and fingerlings per unit area.
  • Allows for easy collection of fry from tilapia brooders and rearing of fingerlings inside a pond.
  • Offers large benefits for all-male fingerling production through manual sexing, hormonal reversal, or YY male technology.
  • Suitable for various aquaculture species such as tilapia, catfish, carp, prawn, and crayfish.
  • Can be installed in different water bodies such as earthen ponds, riverbeds, or large concrete tanks.
  • Can be adjusted in shape and size according to the dimension and depth of the water body.
  • Affordable and simple to build with materials like fine mesh screen netting, wooden poles, or floating barrels.
  • Can be used in ponds stocked with other fish without risk of competition.
  • Suitable for shallow water with low flow rate and level of fluctuation.
  • Allows for periodic scrubbing to prevent clogging and maintain water circulation and quality.
  • Can be cleaned easily with a brush and pond water, ensuring high levels of rearing efficiency through regular inspection and maintenance.

Key points to design your business plan

Utilizing Hapa Nets for Mass Fingerling Hatchery Production streamlines fingerling production, offering fish farmers a cost-effective method. This technology enhances breeding conditions, elevates fingerling survival rates, and promotes sustainable aquaculture methods.

In terms of cost, constructing a hapa using bamboo poles and fine mesh netting typically amounts to approximately US $1 per square meter, with finer meshes incurring additional expenses.

The potential profit from fingerling production in hapa nets varies, ranging from 150 to over 900 fingerlings per square meter monthly. A single hatchery equipped with hapa nets can supply between 8 and 20 fish farmers, delivering significant benefits to the local aquaculture sector.

As this technology is accessible in numerous countries, including Zambia, Uganda, Togo, Tanzania, Sudan, South Sudan, Sierra Leone, Senegal, Rwanda, Nigeria, Niger, Mozambique, Mali, Malawi, Madagascar, Kenya, Ivory Coast, Guinea, Ghana, Ethiopia, Eritrea, Equatorial Guinea, Djibouti, Democratic Republic of the Congo, Central African Republic, Cameroon, Burundi, Burkina Faso, Botswana, Benin, and Angola, ensure to incorporate delivery costs to the business site and account for any import clearance and duties that may apply.

Consider collaborating with agricultural development institutions and agro-dealers for effective implementation.

Additionally, explore the integration of complementary technologies such as All Male Tilapia Fingerlings and Hybrid African Catfish to enhance operational efficiency.


Positive or neutral impact

Adults 18 and over
Positive high
The poor
Positive medium
Under 18
Positive low
Positive high

Positive or neutral impact

Climate adaptability
It adapts really well
Adaptability for farmers
It helps a lot
It helps them grow and thrive
Carbon footprint
It reduces emissions a little
It makes a big difference
Soil quality
It makes the soil healthier and more fertile
Water usage
It uses the same amount of water

Countries with a green colour
Tested & adopted
Countries with a bright green colour
Countries with a yellow colour
Egypt Equatorial Guinea Ethiopia Algeria Angola Benin Botswana Burundi Burkina Faso Democratic Republic of the Congo Djibouti Côte d’Ivoire Eritrea Gabon Gambia Ghana Guinea Guinea-Bissau Cameroon Kenya Libya Liberia Madagascar Mali Malawi Morocco Mauritania Mozambique Namibia Niger Nigeria Republic of the Congo Rwanda Zambia Senegal Sierra Leone Zimbabwe Somalia South Sudan Sudan South Africa Eswatini Tanzania Togo Tunisia Chad Uganda Western Sahara Central African Republic Lesotho
Countries where the technology has been tested and adopted
Country Tested Adopted
Angola Tested Adopted
Benin Tested Adopted
Botswana Tested Adopted
Burkina Faso Tested Adopted
Burundi Tested Adopted
Cameroon Tested Adopted
Central African Republic Tested Adopted
Côte d’Ivoire Tested Adopted
Democratic Republic of the Congo Tested Adopted
Djibouti Tested Adopted
Equatorial Guinea Tested Adopted
Eritrea Tested Adopted
Ethiopia Tested Adopted
Ghana Tested Adopted
Guinea Tested Adopted
Kenya Tested Adopted
Madagascar Tested Adopted
Malawi Tested Adopted
Mali Tested Adopted
Mozambique Tested Adopted
Niger Tested Adopted
Nigeria Tested Adopted
Rwanda Tested Adopted
Senegal Tested Adopted
Sierra Leone Tested Adopted
South Sudan Tested Adopted
Sudan Tested Adopted
Tanzania Tested Adopted
Togo Tested Adopted
Uganda Tested Adopted
Zambia Tested Adopted

This technology can be used in the colored agro-ecological zones. Any zones shown in white are not suitable for this technology.

Agro-ecological zones where this technology can be used
AEZ Subtropic - warm Subtropic - cool Tropic - warm Tropic - cool

Source: HarvestChoice/IFPRI 2009

The United Nations Sustainable Development Goals that are applicable to this technology.

Sustainable Development Goal 8: decent work and economic growth
Goal 8: decent work and economic growth
Sustainable Development Goal 12: responsible production and consumption
Goal 12: responsible production and consumption
Sustainable Development Goal 1: no poverty
Goal 1: no poverty
Sustainable Development Goal 2: zero hunger
Goal 2: zero hunger
Sustainable Development Goal 5: gender equality
Goal 5: gender equality
Sustainable Development Goal 13: climate action
Goal 13: climate action

  1. Deep Cleaning of Dirty Hapa Nets: Remove dirty hapa nets from the pond and soak them with urea for 72 hours. Wash the nets with a suitable cleaner and rinse thoroughly to ensure cleanliness.
  2. Fry Production in Hapa: Utilize brooders weighing approximately 300 grams with a male to female ratio of 1:2 or 1:3. Maintain a stocking density of 4-5 brooders per square meter in the hapa nets. 
  3. Daily Monitoring and Transfer: Inspect the hapa nets daily to identify fry. Transfer the identified fry to other hapa tanks or rearing ponds for further growth and development.
  4. Record-Keeping and Monitoring: Maintain detailed records of the number of fry and fingerlings harvested from each hapa net, along with feed input. This monitoring ensures and helps achieve high rearing efficiency.

Last updated on 22 May 2024