Tilapia (pronounced /tɨˈlɑːpiə/) is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia inhabit a variety of fresh water habitats including shallow streams, ponds, rivers and lakes. Historically they have been of major importance in artisan fishing in Africa and the Levant and are of increasing importance in aquaculture (see tilapia in aquaculture). Tilapia can become problematic invasive species in new warm-water habitats, whether deliberately or accidentally introduced but generally not in temperate climates due to their inability to survive in cool waters, generally below 60 °F (16 °C). (See tilapia as exotic species).
Tilapia is the third most important fish in aquaculture after carps and salmonids, with production reaching 1,505,804 metric tons in 2002[6]. Because of their large size, rapid growth, and palatability, tilapiine cichlids are the focus of major aquaculture efforts, specifically various species of Oreochromis, Sarotherodon, and Tilapia, collectively known colloquially as tilapias. Like other large fish, they are a good source of protein and a popular target for artisanal and commercial fisheries. Most such fisheries were originally found in Africa, but outdoor aquaculture projects in tropical countries such as Papua New Guinea, the Philippines, and Indonesia are underway in freshwater lakes.[6] 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.[7]
Commercially grown tilapia are almost exclusively male. Cultivators use hormones such as testosterone to reverse the sex of newly spawned females. 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.[8]
Whole Tilapia fish can be processed into skinless, boneless (PBO) fillets: the yield is from 30 percent to 37 percent, depending on fillet size and final trim.[9] The use of tilapia in the commercial food industry has led to the virtual extinction of genetically pure bloodlines. Most wild tilapia today are hybrids of several species.
Tilapia have very low levels of mercury[10] as they are a fast-growing and short-lived fish that mostly eats a vegetarian diet and therefore do not accumulate mercury found in prey.[7]
Tilapia is a low total fat, low saturated fat, low calorie, low carbohydrate and low sodium protein source. It is also an excellent source of Phosphorus, Niacin, Selenium, Vitamin B12 and Potassium. [8]
Tilapia are unable to survive in low temperate climates because they require warm water. The pure strain of the Blue Tilapia, Oreochromis aureus, has the greatest cold tolerance and dies at 45 °F (7 °C) while all other species of tilapia will die at a range of 52°-62°F. 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.[11] Because of this, tilapia are on the IUCN's 100 of the World's Worst Alien Invasive Species list.[12] In the United States, tilapia can live only in extreme southern Florida and a few other isolated areas such as power plant discharge zones. Many state fish and wildlife agencies in the United States, Australia, South Africa and elsewhere consider them an invasive species
Tilapia serve as a natural, biological control for most aquatic plant problems. Tilapia consume floating aquatic plants, such as duckweed watermeal (Lemna sp.), most "undesirable" submerged plants and most forms of algae.[14] In the United States and countries such as Thailand, Tilapia are becoming the plant control method of choice, reducing/eliminating the use of toxic chemicals and heavy metal-based algaecides.
Tilapia rarely compete with other "pond" fish for food. Instead, because tilapia consume plants and nutrients unused by other fish species and substantially reduce oxygen depleting detritus, adding tilapia often increases the population, size and health of other fish.
Arizona stocks tilapia in the canals that serve as the drinking water sources for the cities of Phoenix, Mesa and others. The fish help purify the water by consuming vegetation and detritus, greatly reducing purification costs.
Arkansas stocks many public ponds and lakes to help with vegetation control, as a robust forage species and for anglers.
In Kenya tilapia help control mosquitoes which cause malaria. They consume mosquito larvae, which reduces the numbers of adult females, the disease’s vector[15]
Tilapia also provide an abundant food source for aquatic predators.
Larger tilapia species are generally viewed as poor community aquarium fish because they eat plants, dig up the bottom and fight with other fish. However, tilapia are often raised in aquariums as a food source due to their rapid growth and tolerance for high stocking densities and poor water quality. The smaller West African species, such as Tilapia joka and those species from the crater lakes of Cameroon are more popular. In specialized cichlid aquaria tilapias can be mixed successfully with non-territorial cichlids, armoured catfish, tinfoil barbs, garpike and other robust but peaceful fish. Some species, including Tilapia buttikoferi, Tilapia rendalli,Tilapia mariae ,Tilapia joka and the brackish-water Sarotherodon melanotheron melanotheron, which have attractive patterns and are quite decorative
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