Introduction to African Catfish Hatcheries
African catfish hatcheries can be highly profitable if they have a well-designed culture system and a dedicated team of hatchery staff. However, the results achieved by farmers can vary greatly due to a lack of knowledge, inadequate management practices, or poorly constructed hatcheries. Some farmers may require as many as 200 eggs to produce a single juvenile, while others can achieve the same outcome with just five eggs. In this context, an African catfish juvenile refers to a two-month-old fish weighing around eight grams.
In Europe, African catfish hatcheries are equipped exclusively with recirculation systems, as the climate conditions do not permit other alternatives. In tropical regions, hatcheries use either recirculation systems alone or a combination of recirculation systems, flow-through systems, hapas, and small ponds.
Many African countries struggle to meet the demand for juveniles, leading to high prices and often subpar quality of African catfish fingerlings/juveniles in the market. While numerous African entrepreneurs are attracted to the idea of starting a hatchery, only a select few achieve success. In the long term, I personally believe that medium-sized operations utilizing well-distributed recirculation technology throughout the country are more viable than relying solely on small-scale backyard farmers who produce limited quantities of fingerlings. Such medium-sized hatcheries can provide people with high-quality fingerlings/juveniles and support them in growing these fish to marketable sizes.
Layout of an African catfish hatchery using recirculation systems
To ensure optimal conditions for each life stage of African catfish, our hatchery design incorporates various sections, each dedicated to a specific developmental phase.
- Broodstock section: Houses mature broodstock in spacious tanks with controlled water conditions, temperature, and lighting.
- Incubation section: Specialized incubators provide optimal conditions for egg hatching, including controlled water parameters, temperature, and pH levels.
- Fingerling section: Small tanks provide optimal conditions for growing of fry to fingerlings, including controlled water parameters, and temperature.
- Juvenile section: Medium sized tanks provide optimal conditions for growing of fingerlings to juveniles, including controlled water parameters, and temperature
Each section operates with specific procedures for feeding, water monitoring, tank maintenance, and disease prevention, dedicated to the catfish’s developmental stages.
System required for catfish broodstock
We recommend utilizing either a recirculation system (preferably) or a flow-through system to house your broodstock fish. However, please note that a flow-through system is only viable if the local climate permits it. The fish tanks can be constructed from materials such as glass fiber, polyethylene, or concrete. The fish tanks should be situated in a quiet environment to minimize the risk of stress for the fish. Furthermore, it is preferable to maintain a dark setting, such as a windowless building illuminated solely by a small work light.
Stocking of catfish broodstock
The required number of broodstock depends on the success rate of spawning. For instance, in theory, one female can be utilized for eight spawnings per year, yielding 3.2 kg of eggs. This amounts to around 1.6 million eggs, and with a minimum survival rate of 10% until the juvenile stage, the annual production would reach 160,000 African catfish juveniles.
Feed for catfish broodstock
Adequate quality fish feed should be provided to the African catfish broodstock. Typically, we recommend a specialized feed specifically formulated for broodstock. This feed contains higher concentrations of proteins, fats, vitamins, and specific amino acids compared to regular grower feeds. The main difference between broodstock feed and standard grow-out feed lies in the composition of the diet. Broodstock feed for African catfish incorporates premium-quality fish meal, with fat sourced exclusively from fish oil (no vegetable oils are used). Micro-nutrients are also added to the feed. Extensive testing has been conducted primarily on salmonids, demonstrating that this feed improves the fecundity of both sexes, enhances hatching rates, and reduces the occurrence of deformities in the fry. The inclusion of astaxanthin and Vitamin E in the feed prevents oxidative damage to young tissues caused by free radicals. Furthermore, the immune system of the broodstock is bolstered by the addition of beta-glucans, which serve as immune stimulants within the feed. Researchers speculate that these benefits may also be transmitted to the eggs. At our former farm, we used automatic feeders to provide feed to the broodstock.
Even in tropical regions, we prioritize importing premium compound feed from a reputable (European) producer instead of utilizing locally produced and often unreliable feeds. We firmly believe that a solid foundation is vital for the successful development of the offspring.
System required for incubating catfish eggs
The incubation system should be located in a temperature-controlled room, maintained at a constant temperature of 30°C. Even in tropical regions, nighttime water temperatures can drop to 24°C, which negatively impacts fry growth and health. To address bacterial blooms and fungal growth occurring after hatching, the implementation of a UV-C unit is crucial. When eggs hatch, a significant amount of egg fluids and unhatched eggs enter the water, creating a fertile environment for bacteria and fungi. By continuously introducing fresh water and utilizing the UV-C device, the proliferation of these unfavorable organisms can be prevented. The system should be designed for easy accessibility to facilitate proper cleaning and inspection.
Aquaculture ID from the Netherlands offers top-of-the-line plug and play hatching systems, widely regarded as some of the best available on the market. With over 30 years of experience in breeding African catfish and utilizing their system in their own farm, Aquaculture ID has developed a highly reputable and reliable solution.
Stocking African Catfish Incubation System
Fertilized eggs are distributed over a sieve, immersed in oxygen-rich water to minimize egg mortality. At a water temperature of 29-30°C, the eggs hatch within approximately 24 hours. The larvae pass through the mesh of the mosquito net, while dead eggs and egg shells can be easily removed. During the first two days, the larvae absorb the yolk sac and develop their intestines. Afterward, they begin swimming freely in search of food, gradually transitioning in color from transparent green to brown.
Maintenance of the Incubation System
Each hatching cycle spans 13 days, comprising 2 days of system preparation, 3 days for hatching and yolk sac absorption, 7 days for fry growth, and 1 day for harvesting and cleaning. Thorough cleaning and disinfection of the system between each cycle are crucial. Our recommendation for system disinfection is to utilize hydrogen peroxide. Hydrogen peroxide undergoes decomposition into oxygen and water, ensuring the absence of toxic residues, unlike chlorine, which can potentially leave behind harmful substances.
Feeding African catfish fry
Initially, the primary feed for African catfish fry should be live Artemia nauplii hatched on-site. Experience has shown that starting with live Artemia yields higher survival rates and better growth compared to dry larval feeds or encapsulated Artemia. If dry feed is utilized, begin with dry feed before introducing Artemia nauplii. Observing the feeding behavior and stomach filling helps prevent overfeeding or underfeeding. Well-fed African catfish larvae display full bellies and settle at the bottom of the tank.
System required for growing fingerlings
To establish optimal growing conditions, we suggest employing recirculation systems. It is important to ensure that the fish tanks are not excessively deep, allowing the fry to easily access the water surface for air intake. Depending on local conditions, you have the option of either utilizing multiple tanks connected to a shared filter system or having individual tanks, each with its own filter system. Each choice comes with its own advantages and disadvantages, necessitating careful consideration before initiating the design phase.
During this phase the fry can grow from 0,1 gram to approximately 0,5-1,0 gram fingerlings.
Feeding African catfish fingerlings and juveniles
For the growth of fingerlings into juveniles, it is recommended to feed them multiple times a day at regular intervals using dry feed of a well respected feed factory. It is important to note that African catfish remain active even in the dark.
Once the fingerlings reach a weight range of 0,5 to 1,0 grams, they can either be sold to customers or transferred to the juvenile section of the hatchery.
This section is designed for the growth of fingerlings weighing approximately 1.0 gram to juveniles weighing around 5-10 gram. Farmers prefer this size range as the juveniles are more robust compared to fingerlings, resulting in lower mortality rates, particularly attributed to cannibalism. It is recommended to house these systems indoors, maintaining a constant temperature of 28°C. To minimize expenses, the flow-through technique can be implemented during this phase. However, this method is dependent on the suitability of the local climate and the ideal water parameters, such as temperature, of the incoming water.
Cannibalism is the primary cause of fish loss during this stage. However, implementing proper grading techniques, even during the growth period, can help minimize this issue. As the juveniles continue to grow towards the consumption size, the loss rate becomes less than 10%.