Tilapia
Tilapia is the common name for nearly a hundred species of cichlid fish from the coelotilapine, coptodonine, heterotilapine, oreochromine, pelmatolapiine, and tilapiine tribes, with the economically most important species placed in the Coptodonini and Oreochromini. Tilapia are mainly freshwater fish native to Africa and the Middle East, inhabiting shallow streams, ponds, rivers, and lakes, and less commonly found living in brackish water. Historically, they have been of major importance in artisanal fishing in Africa, and they are of increasing importance in aquaculture and aquaponics. Tilapia can become a problematic invasive species in new warm-water habitats such as Australia, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cold water.
Traditionally a popular and affordable food in the Philippines with a mild taste, tilapia has been the fourth-most consumed fish in the United States since 2002, favored for its low cost and easy preparation. It is commonly fried or broiled as part of a dish.
Etymology
The common name "tilapia" is based on the name of the cichlid genus Tilapia, which is itself a latinization of either tlhapi, the Tswana word for 'fish', or the Greek word tilon, referring to a fish mentioned by Aristotle, combined with apios, meaning 'distant'. Scottish zoologist Andrew Smith named the genus in 1840.History
The aquaculture of Nile tilapia dates from Ancient Egypt, where it was represented by the hieroglyph K1, of the Gardiner list: ?.The fish symbolized rebirth in Egyptian art, and was associated in Egyptian belief-systems with Hathor, goddess of fertility and abundance.
The tilapia was also said to accompany and protect the sun god on his daily journey across the sky.
Tilapia were one of the three main types of fish caught in Talmudic times from the Sea of Galilee, specifically the Galilean comb. It is sometimes known by the name "St. Peter's fish", which comes from the narrative in the Gospel of Matthew about the apostle Peter catching a fish that carried a coin in its mouth. Though the passage does not name the fish, several tilapia species are found in the Sea of Galilee, where the narrative recounts the event that took place. These species have been the target of small-scale artisanal fisheries in the area for thousands of years.
Characteristics
Tilapia typically have laterally compressed, deep bodies. Like other cichlids, their lower pharyngeal bones are fused into a single tooth-bearing structure. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labor between the "true jaws" and the "pharyngeal jaws". This means they are efficient feeders that can capture and process a wide variety of food items. Their mouths are protrusible, usually bordered with wide and often swollen lips. The jaws have conical teeth. Typically, tilapia have a long dorsal fin, and a lateral line that often breaks towards the end of the dorsal fin, and starts again two or three rows of scales below. Some Nile tilapia can grow as long as.Other than their temperature sensitivity, tilapia exist in or can adapt to a very wide range of conditions. An extreme example is the Salton Sea, where tilapia introduced when the water was merely brackish now live in salt concentrations so high that other marine fish cannot survive.
Tilapia are also known to be mouth-brooding species, which means they carry the fertilized eggs and young fish in their mouths for several days after the yolk sac is absorbed.
Species
Historically, all tilapia have been included in their namesake genus Tilapia. In recent decades, some were moved into a few other genera, notably Oreochromis, and Sarotherodon. Even with this modification, apparently Tilapia was strongly poly– or paraphyletic. In 2013, a major taxonomic review resolved this by moving most former Tilapia spp. to several other genera. As a consequence, none of the species that are of major economic importance remain in Tilapia, but are instead placed in Coptodon, Oreochormis, and Sarotherodon.Exotic and invasive species
Tilapia have been used as biological controls for certain aquatic plant problems. They have a preference for a floating aquatic plant, duckweed, but also consume some filamentous algae. In Kenya, tilapia were introduced to control mosquitoes, which were causing malaria, because they consume mosquito larvae, consequently reducing the numbers of adult female mosquitoes, the vector of the disease. These benefits are, however, frequently outweighed by the negative aspects of tilapia as an invasive species.Tilapia are unable to survive in temperate climates because they require warm water. The pure strain of the blue tilapia, Oreochromis aureus, has the greatest cold tolerance and dies at, while all other species of tilapia die at a range of . As a result, they cannot invade temperate habitats and disrupt native ecologies in temperate zones; however, they have spread widely beyond their points of introduction in many fresh and brackish tropical and subtropical habitats, often disrupting native species significantly. Because of this, tilapia are on the IUCN's 100 of the World's Worst Alien Invasive Species list. In the United States, tilapia are found in much of the south, especially Florida and Texas, and as far north as Idaho, where they survive in power-plant discharge zones. Tilapia are also currently stocked in the Phoenix, Arizona, canal system as an algal growth-control measure. In a Washington, D.C. fishing report from 21 June 2024, it was reported that an angler caught a tilapia on a crankbait at the Jones Point Park under the Woodrow Wilson Bridge, which is on the Potomac River. Many state fish and wildlife agencies in the United States, Australia, South Africa, and elsewhere consider them to be invasive species.
Aquarium species
Larger tilapia species are generally poor community aquarium fish because they eat plants, dig up the bottom, and fight with other fish. The larger species are often raised as a food source, though, because they grow rapidly and tolerate high stocking densities and poor water quality.Smaller West African species, such as Coelotilapia joka and species from the crater lakes of Cameroon, are more popular as aquarium fish. In specialised cichlid aquaria, tilapia can be mixed successfully with nonterritorial cichlids, armored catfish, tinfoil barbs, garpike, and other robust fish. Some species, including Heterotilapia buttikoferi, Coptodon rendalli, Pelmatolapia mariae, C. joka, and the brackish-water Sarotherodon melanotheron, have attractive patterns and are quite decorative.
Commercial species
Tilapia were originally farmed in their native Africa and Levant. Fast-growing, tolerant of stocking density, and adaptable, tilapia have been introduced to and are farmed extensively in many parts of Asia and are increasingly common aquaculture targets elsewhere.Aquaculture
Farmed tilapia production in 2002 worldwide was about annually, with an estimated value of US$1.8 billion, about equal to those of salmon and trout.Unlike carnivorous fish, tilapia can feed on algae or any plant-based food. This reduces the cost of tilapia farming, reduces fishing pressure on prey species, avoids concentrating toxins that accumulate at higher levels of the food chain, and makes tilapia the preferred "aquatic chickens" of the trade.
Because of their large size, rapid growth, and palatability, tilapia cichlids are the focus of major farming efforts, specifically various species of Oreochromis, Sarotherodon, and Coptodon. Like other large fish, they are a good source of protein and popular among artisanal and commercial fisheries. Most such fisheries were originally found in Africa, but outdoor fish farms in tropical countries, such as Papua New Guinea, the Philippines, and Indonesia, are underway in freshwater lakes. In temperate zone localities, tilapiine farming operations require energy to warm the water to tropical temperatures. One method uses waste heat from factories and power stations.
At 1.3 million tonnes per annum, China is the largest tilapia producer in the world, followed by Egypt with 0.5 million. The US, by comparison, produces 10 thousand tonnes against a consumption of 2.5 million.
In modern aquaculture, wild-type Nile tilapia are not too often seen, as the dark color of their flesh is not much desired by many customers, and because it has a bit of a reputation of being a rough fish associated with poverty. However, they are fast-growing and give good fillets; leucistic breeds which have lighter meat have been developed and are very popular.
Hybrid stock is also used in aquaculture; Nile × blue tilapia hybrids are usually rather dark, but a light-colored hybrid breed known as "Rocky Mountain White" tilapia is often grown due to its very light flesh and tolerance of low temperatures.
Commercially grown tilapia are almost exclusively male, typically done by adding male sex hormone in the food to the tilapia fry, causing any potential female tilapia to change sex to male. It can also be achieved through hybridization of certain tilapia species or the use of so-called "supermales" that have homozygous male sex chromosomes. Males are preferred because they grow much faster than females. Additionally, because tilapia are prolific breeders, the presence of female tilapia results in rapidly increasing populations of small fish, rather than a stable population of harvest-size animals.
Tilapia, as a "traditional" dish, was first introduced in the Philippines in 1950 with Mozambique tilapia followed by Nile tilapia in 1972 from Thailand. Strains such as terapon and white goby were abundant in Laguna de Bay. In 1988, WorldFish, Filipino and Norwegian researchers started aquaculture of the Genetically Improved Farmed Tilapia.
Other methods of tilapia population control are polyculture, with predators farmed alongside tilapia or hybridization with other species.