TAAT Online Learning Materials
Aquaculture accounts for more than 43% of global fish supply but only 2% in Africa, mainly from Egypt and Nigeria. Aquaculture Compact has been implemented in 12 targeted African countries: Burundi, Cameroon, Cote d’Ivoire, DRC, Ghana, Kenya, Malawi, Nigeria, Republic of Benin, Tanzania, Togo, and Zambia. The main objectives of TAAT Aquaculture Compact are: creating an enabling environment for technology adoption; facilitating effective delivery of technologies to aquaculture value chain actors; and raising aquaculture production and productivity through identification and deployment of appropriate technologies. The technologies that have been developed and delivered under the compact are:
- fast-growing fish seeds and improved fish rearing system
- Quality low-cost fish feed using locally available raw materials like formulation of low-cost and feed feeding and management techniques and,
- Improved postharvest technologies and product development including, solar tent drying techniques, smoking kiln technology, and 12 value-added fish products. These proven technologies play a great role to have access to quality fish seed, low-cost fish feed, and value-added fish products to foster the needed change through farm-level productivity, value chain development, and improved nutritional diet in Africa.
Resource for dissemination notes: https://library.faraafrica.org/2021/03/01/fdn-42_2021-the-case-of-mono-sex-tilapia-fish-technology-fara-taat/
Origin Of Tilapia
- Tilapia is one of the world’s most important farmed fish after carp
- “Tilapia,” the common name, is broadly applied to a group of cichlid fish species that originated in Africa, the Middle East, and the Mediterranean. They are some of the oldest fish to be cultured.
- Tilapia can be produced in either an extensive (in earthen ponds) or intensive (in cages and tanks) system and in either freshwater or saltwater in tropical and subtropical climates.
- The most commonly cultured tilapia species, and the most dominant worldwide, is the Nile Tilapia (Oreochromis niloticus).
- Tilapia tolerates a wide range of environmental conditions and is a suitable polyculture candidate with carps and catfish.
- Tilapia’s white flesh has a mild flavor to it. It is usually called aquatic chicken because it breeds easily and can be mass-produced.
- Tilapia eats pellets made from plant sources (largely corn and soy) and this results in rapid weight gain.
- In 1994, ICLARM, now known as WorldFish, introduced the genetically improved farmed
tilapia (GIFT) strain to improve tilapia productivity and marketing.
- GIFT (Oreochromis niloticus) grows bigger, making it more acceptable to consumers. Its international market size ranges from 450 to 550 g.
- Culturing GIFT is widely gaining popularity in developing countries and is now popular among farmers in Africa.
The Rationale for Mono-Sex Tilapia Production
- Tilapia is a very prolific fish species
- Female tilapia has a low conversion ratio of feed to flesh which prevents optimal growth because metabolic energy is directed toward reproduction.
- Male tilapia are bigger, more economically attractive because metabolic energy is channelled toward growth, which makes them grow faster.
- It is better to adopt mono sex culture.
- Mono sex tilapia (all-male production) can be obtained using manual sexing, hormones, genetically improved farmed tilapia, YY male technology, or hybrids.
- Producing mixed sex is technically easy but the yield is always poor.
- At harvest, weights are low and the sizes are mixed.
- Mono sex culture is more technical, but it is easier to produce all male tilapia fingerlings in any production cycle—as high as 98%.
- The use of hapas for producing mass production of tilapia allows for a higher survival rate.
- Superior with respect to growth and yield per unit area with uniform sizes at harvest.
- They possess the ability to feed on natural foods in the pond and thrive equally well on supplementary feeds
- Highly resistant to disease and tolerant of adverse weather, wide temperature fluctuations (12oC–40oC) and saline water (12–15 ppt).
- Reduction of sexual/territorial behavior
- Reduction of variation in harvest size
- Higher economic value and profitability
- The high adoption rate for commercialization
- The growth rate of individual fish is slower due to high stocking densities.
- It is challenging and difficult to maintain good water quality.
- Densely stocked systems are prone to ill health.
- Tilapia is less stress-tolerant compared with some indigenous cultured species, like catfish.
- The use of hormones on human health has a perceived negative effect.
Advantages and disadvantages of the hapa method
- Brooders and fry are easily handled.
- Production on a per unit area is high.
- Minimized lose of fry.
- Very sheep compared with concreate or tanks.
- Hapas can be set up in ponds stock with fish.
- Hapa mesh will get clogged limiting water circulation and needing periodic scrubbing.
- Poor water quality is likely due to uneaten feed and fish waste.
- Management is more demanding compared to the other methods.
Success Stories from Beneficiaries
1. Djam Wilfred Chiatoh, Nirex Farms Ltd, Yaoundé- Cameroon
Nirex Farm established in 2016 is owned and managed by an experienced young entrepreneur. The farm is newly introduced to apply the mono sex male tilapia technology. Djam Wilfred adopted and produced 230,000 mono sex tilapia in 2019 after receiving technical skills training by professionals on production of mono-sex tilapia fingerlings (Figure 5). Consequently, as a spillover effect, more than 70 fish farmers were trained by Nirex farms, adopted and scaled up mono sex male tilapia thereby earning additional income of USD 27,000. As reported by the manager, sourcing for quality tilapia parent stock is one of the main challenges confronted during the project time.
Reproduction in Tilapia - Sexual Dimorphism
- Sexual dimorphism is a condition where two sexes of the same species exhibit different characteristics apart from the differences in their sexual organs. Such differences may be in color, shape and size, which makes males distinct from females.
- Generally, female tilapia can be distinguished by looking at the genital papillae behind the anus. It has a rounded shape with a triangular indentation in the centre
- Males genital papilla is tapered in shape, while females have a separate opening for eggs and urine (urinary opening and oviduct).
- Females have three apertures: anus, urinary and genital
- Males have the same opening for sperm and urine
- Mature female tilapia fish spawn 6–12 times a year.
- The number of eggs in one batch ranges from 100 to 2000 depending on the size of the female.
Successful farming requires fish breeders to select broodstock for increased production in quality and quantity of fish seeds. Broodstock is a good predictor of fecundity and can be used to select fish of higher seed production.
When selecting broodstock, farmers should look for the following:
- Brooders must be secured from a trusted source and advisable to procure brooders from a Multiplication Centre for genetically improved strains
- Younger brooders of one year should be selected.
- It is preferable for brooders to weigh 150-300 g on average
- Highly vigorous, well-fed brooders must be selected
- Avoid feeble or diseased brooders
- The brooder should have no wounds or parasites
- The body should possess the required shape, conformations, and proportions.
- The sex ratio of males to females for all types of breeding facilities ranges from 1:2-3 (male: female) per m2
- Replace brooders with new ones of the same species every three years
- Keep records for each batch of broodstock
- Remove the premaxilla of the male fish by clipping it with scissors to prevent injury or the death of females during courtship
- Spawning is so stressful to the female brooders. Therefore, the need for balanced feeds to improve reproductive capacity and to produce highly vigorous fry, free from malformations
- Floating feeds are currently used to reduce feed loss and maintain water quality.
- Loss of appetite is considered indicative of the number of brooders carrying eggs in each unit
- Feed broodstock daily with formulated dry pellets that contain 30%–35% dietary crude protein
- Feed them twice daily at a feeding rate of 1%–2% of their weight
- Remove the eggs to prevent the females from incubating their eggs orally. This allows better control of hatching and lets the female produce another batch of eggs.
Seed collection and egg incubation
- Tilapia show a high degree of parental care for their eggs and fry
- Nile tilapia (Oreochromis niloticus) and three-spotted tilapia (Oreochromis andersonii) are mouthbrooders
- They incubate the eggs in their mouth until they are fully hatched
- Collecting fry collection from ponds usually occurs every 7–21 days
- Female broodstock must be checked regularly for eggs. If they carry eggs in their mouths, they must be collected and transferred into the hatchery.
- Transfer harvested eggs and yolk-sac larvae to the hatchery section
- Clean and washed with clean water first then disinfected with potassium permanganate (2 ppm which is 2 mg in 1 liter of clean water) for 30 minutes and then washed in clean water again.
- Gently transfer the eggs into incubating Jar or tray which can be a more effective method for creating optimal health conditions of fry and for better control. However, it is very labor-intensive and not the most cost-effective technique
- Hapa technology is a convenient means of collecting and rearing tilapia fry and cost-effective