Nile Tilapia Farming: A Production Guide
How Nile tilapia (Oreochromis niloticus) is farmed: biology and tolerance, culture systems, monosex culture, temperature and feeding, seed supply, growth to market and main diseases.
Overview
Nile tilapia (Oreochromis niloticus) is a warm-water cichlid native to Africa and now the most widely farmed tilapia and one of the most important farmed food fish in the world. FAO and WorldFish report global Nile tilapia production in the multi-million-tonne range, having grown from about 3.5 million tonnes in 2010 to roughly 6 million tonnes by 2018. It is farmed widely because it grows fast, feeds low on the food chain, and is hardy and easy to breed.
Biology and tolerance
Nile tilapia is an omnivore that tolerates a wide range of conditions, including poor water quality, low dissolved oxygen and a range of salinities. It is, however, a tropical species sensitive to cold: sources give a lower lethal temperature of roughly 7 to 12 °C, so culture is limited to warm climates or heated systems. Optimal growth occurs at warm temperatures, broadly reported around 27 to 32 °C.
Culture systems
- Earthen ponds: the most common and lowest-input system, from extensive to semi-intensive.
- Cages and net pens: in lakes and reservoirs, allowing intensive feeding in open water.
- Tanks and recirculating systems (RAS): for intensive, controlled production.
- Biofloc systems: high-density culture suited to tilapia's particle-feeding habit.
Monosex culture
Tilapia breed prolifically and at a small size, so mixed-sex ponds fill with unwanted fry that stunt growth. To avoid this, farmers raise all-male (monosex) stock, since males grow faster. Monosex populations are produced by manual sexing, by hybridization, or most commonly by sex reversal, in which first-feeding fry are fed a hormone (such as 17α-methyltestosterone) during the sex-differentiation window. Temperature during early development can also influence sex ratio.
Feeding and growth
As an omnivore, Nile tilapia uses natural pond food, supplemental feed, or complete formulated diets depending on intensity, and it converts feed efficiently relative to carnivorous species. Selective breeding has improved performance: the Genetically Improved Farmed Tilapia (GIFT) strain, developed from 1988 by WorldFish with partners in the Philippines and Norway, is a faster-growing line now used widely in tilapia farming. Fish are typically grown to a market size of several hundred grams.
Seed supply and reproduction
Tilapia are mouthbrooders that spawn readily in captivity, which makes seed production straightforward. Broodstock are held in ponds, tanks or hapas, and fry are collected and then sex-reversed or sorted to produce monosex fingerlings for stocking. Reliable, year-round seed supply in warm climates is one reason tilapia farming has expanded so rapidly.
Main diseases
Intensively farmed tilapia are affected by several diseases, notably bacterial streptococcosis (Streptococcus species) and francisellosis (Francisella), and by the viral disease tilapia lake virus (TiLV), an emerging threat to tilapia aquaculture. Good water quality, controlled stocking density and biosecurity reduce disease risk, and breeding programs are working toward more disease-resistant strains.