Hybrid tilapias are crosses between different species of ''

Oreochromis ''Oreochromis'' is a large genus of oreochromine cichlids, fishes endemic to Africa and the Middle East. A few species from this genus have been introduced far outside their native range and are important in aquaculture. Many others have very ...

'' tilapias developed for aquaculture, either through natural hybridization, or more often artificially, in an effort to improve yields through improving various qualities of the fish, such as growth and hardiness. Hybrids are often divided into two varieties: gray tilapia and red tilapia, which are assigned variable binomial names based on the author, though the red hybrid is more often distinguished due to its distinct coloration. Tilapia is an extremely important aquacultured resource; in 2022, worldwide production of tilapia (reported as ''Oreochromis niloticus'') reached produced from aquaculture and captured, ranking 5th among all aquacultured species produced behind

whiteleg shrimp Whiteleg shrimp (''Litopenaeus vannamei'', synonym ''Penaeus vannamei''), also known as Pacific white shrimp or King prawn, is a species of prawn of the eastern Pacific Ocean commonly caught or farmed for food. Description ''Litopenaeus vannam ...

, cupped oysters,

grass carp The grass carp (''Ctenopharyngodon idella'') is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russian ...

, and

silver carp The silver carp or silverfin (''Hypophthalmichthys molitrix'') is a species of freshwater cyprinid fish, a variety of Asian carp native to China and eastern Siberia, from the Amur River drainage in the north to the Xi Jiang River drainage in ...

Genetics

Hybrid tilapia are most often created through crossing Nile tilapia (''

Oreochromis niloticus ''Oreochromis'' is a large genus of oreochromine cichlids, fishes endemic to Africa and the Middle East. A few species from this genus have been introduced far outside their native range and are important in aquaculture. Many others have ver ...

''), Mozambique tilapia ('' O. mossambicus''), blue tilapia ('' O. aureus''), and/or the Wami tilapia ('' O. hornorum''), though pure Wami tilapia is considered to have poorer growth rates. The Nile tilapia is often considered the best overall in tropical aquaculture for its tolerance of dense stocking, Mozambique tilapias (and hybrids) tolerate salinities from

brackish water Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuary ...

conditions, and blue tilapias are the most cold tolerant. Hybridization is done intentionally to try achieve superior qualities in the resultant offspring (

hybrid vigor Heterosis, hybrid vigor, or outbreeding enhancement is the improved or increased function of any biological quality in a Hybrid (biology), hybrid offspring. An offspring is heterotic if its trait (biology), traits are enhanced as a result of m ...

); in nature, tilapias hybridize readily between species and even genera, and there are no reports of sterility in hybrids (which is often the case in hybrids of other forms of animals, such as the

mule The mule is a domestic equine hybrid between a donkey, and a horse. It is the offspring of a male donkey (a jack) and a female horse (a mare). The horse and the donkey are different species, with different numbers of chromosomes; of the two ...

). Crossing stocks of the same species doesn't produce significant hybrid vigor, though it is useful in creating higher

genetic variability Genetic variability is either the presence of, or the generation of, genetic differences. It is defined as "the formation of individuals differing in genotype, or the presence of genotypically different individuals, in contrast to environmentally ...

for future breeding. Pla thapthim

''Red hybrid tilapia'' (reported as ''Oreochromis mossambicus × O. niloticus'', ''O. niloticus × O. mossambicus'', ''O. aureus × O. mossambicus'', ''O. spp.'', ''O. sp.'', or simply not given a scientific name at all) possess multiple strains; among them are Taiwanese red tilapia (

reddish Reddish is an area of the Metropolitan Borough of Stockport, Greater Manchester, England, south-east of Manchester city centre. At the 2011 United Kingdom census, 2011 census, the population was 28,052. Historic counties of England, Historical ...

-orange ''O. mossambicus'' ♀ × WT ''O. niloticus'' ♂), Florida red tilapia (WT ''O. hornorum'' ♀ × red-

gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

''O. mossambicus'' ♂), Israel red tilapia (red/pink Nile tilapia × WT blue tilapia), Malay red tilapia (''Oreochromis niloticus'' × ''O. mossambicus''), and other unknown strains originating from undocumented crosses between these "original" strains and

wild type The wild type (WT) is the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, " ...

fish. Their color arises from a

mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...

in either or both parent, which may ( F1) or may not be hybrids themselves. Taiwanese red tilapia presumably originated from an "

albino Albinism is the congenital absence of melanin in an animal or plant resulting in white hair, feathers, scales and skin and reddish pink or blue eyes. Individuals with the condition are referred to as albinos. Varied use and interpretation of ...

" (or

leucistic Leucism () is a wide variety of conditions that result in partial loss of pigmentation in an animal—causing white, pale, or patchy coloration of the skin, hair, feathers, scales, or cuticles, but not the eyes. It is occasionally spelled ''leu ...

) ''O. mossambicus''; these color

s were first noticed in 1968, 22 years after the species was first introduced in Taiwan, which started with a founding population of 12 adult fish. This strain was "fixed" by crossing ''O. mossambicus'' possessing mutant coloration with ''O. niloticus'', which resulted in an increase of the mutant coloration in produced fry (from 30% in 1969 to 80% in 1974) along with a marked increase in yield. The strain was

commercialized Commerce is the organized system of activities, functions, procedures and institutions that directly or indirectly contribute to the smooth, unhindered large-scale exchange (distribution through transactional processes) of goods, services, and ...

in 1979.

''Gray hybrid tilapia'' (reported as ''Oreochromis niloticus'' x ''O. aureus'') are often reported as one of their parent species or not reported to be hybrids at all, as their coloration conforms more closely to the wild type, so are less distinct than the red fish. Molobicus strain tilapias, developed in the Philippines, were developed by crossing GIFT tilapia with

feral A feral (; ) animal or plant is one that lives in the wild but is descended from domesticated individuals. As with an introduced species, the introduction of feral animals or plants to non-native regions may disrupt ecosystems and has, in som ...

''O. mossambicus''. The different strains of hybrids may be distinguished based on their

morphometric Morphometrics (from Greek μορΦή ''morphe'', "shape, form", and -μετρία ''metria'', "measurement") or morphometry refers to the quantitative analysis of ''form'', a concept that encompasses size and shape. Morphometric analyses are co ...

characters; their

genotypical The genotype of an organism is its complete set of genetic material. Genotype can also be used to refer to the alleles or variants an individual carries in a particular gene or genetic location. The number of alleles an individual can have in a ...

difference is reflected in their phenotype.

Sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

is observed even in F2 hybrids, the expression of which is regulated by the ''amh'' gene. The ''dusp2'', ''rtn4r'', ''bhmt1'', ''adamts12'', and ''s100p'' genes are linked to growth. YY male tilapias (sometimes referred to as " supermale tilapia") were developed in an effort to improve growth in tilapia cultures; these are produced through crossing

estrogen Estrogen (also spelled oestrogen in British English; see spelling differences) is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three ...

-treated males (which become phenotypically female) with normal males, producing offspring which are phenotypically 75% male and 25% YY. Subsequent crossing of YY males with XX females produce offspring which were 99.6% males.

Production

School_of_presumably_nile_tilapia_or_mujair_in_the_school%27s_fishponds

Tilapia are aquacultured in

pond A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing ...

s both earthen and concrete,

irrigation canal Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface f ...

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

s, paddy fields, and in natural

waterway A waterway is any Navigability, navigable body of water. Broad distinctions are useful to avoid ambiguity, and disambiguation will be of varying importance depending on the nuance of the equivalent word in other ways. A first distinction is ...

s, such as

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

s, either released to free-roam or in floating cages. ''O. mossambicus'' and resultant hybrids may thrive in saltwater, reproducing well in

salinities Salinity () is the saltiness or amount of salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensionless and equal to ...

of 10-15 ppt, though fry do best at lower salinities. ''O. aureus'' is the most cold tolerant and can survive in waters warmer than ; the other species perish at . Tilapia can tolerate

dissolved oxygen Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can ...

levels of less than , lower than any other farmed fish that cannot breathe air. Hybrids may be hardy, being tolerant of high salinities, high temperature, high concentrations of

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

, and low oxygen levels, allowing them to be stocked at a high density. All members of ''Oreochromis'' including hybrids are considered

mouthbrooder Mouthbrooding, also known as oral incubation and buccal incubation, is the care given by some groups of animals to their offspring by holding them in the mouth of the parent for extended periods of time. Although mouthbrooding is performed by a va ...

s. As they are omnivorous, tilapia can be fed

phytoplankton Phytoplankton () are the autotrophic (self-feeding) components of the plankton community and a key part of ocean and freshwater Aquatic ecosystem, ecosystems. The name comes from the Greek language, Greek words (), meaning 'plant', and (), mea ...

zooplankton Zooplankton are the heterotrophic component of the planktonic community (the " zoo-" prefix comes from ), having to consume other organisms to thrive. Plankton are aquatic organisms that are unable to swim effectively against currents. Consequent ...

, benthic

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

, insect larvae, artificial feed, or suspended debris in the water column. They are fast growing, able to grow from in 9 months, with males growing faster than females. Care must be taken to prevent stunting, especially in high-density cultures. Methods to prevent stunting include the creation of monosex (all-male) cultures; through YY males; treating cultures with

steroid A steroid is an organic compound with four fused compound, fused rings (designated A, B, C, and D) arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes t ...

s/male hormones, which reverses the sex of potential female fish, crossing pure-strain Wami tilapia with either Niles or Mozambique tilapia, or crossing Nile tilapia with blues. Additionally, tilapia populations are affected by multiple diseases, which is exacerbated when the fish are densely stocked. Outbreaks may result in fish-kills. Supplementing cultured populations with various vitamins to prevent

deficiency A deficiency is generally a lack of something. It may also refer to: *A deficient number, in mathematics, a number ''n'' for which ''σ''(''n'') < 2''n'' * The

Food and Agriculture Organization The Food and Agriculture Organization of the United Nations; . (FAO) is a specialized agency of the United Nations that leads international efforts to defeat hunger and improve nutrition and food security. Its Latin motto, , translates ...

(FAO) often reports the production of these hybrids as one of their parent species; they are not always distinguished from their ancestral, wild species. Additionally, production may not always be reported to the FAO. In 2015, the top producers of tilapias worldwide were China (31%, ), Indonesia (20%, ), Egypt (15%, ), Bangladesh (), and Viet Nam (); worldwide, the total production of aquacultured tilapia in 2015 reached , 68.9% of which was reported as "redbreast" tilapia, and 8% as hybrids between the blue and Nile tilapia. This yield was valued at $8.9 million. In 2022 worldwide production was reported at aquacultured. Oreochromis niloticus at Kanchanaburi market

Oreochromis niloticus at Kanchanaburi market

The Maonan Tilapia Aquaculture Park (with an area of ) produced of tilapia annually for of aquafeed. Farmed tilapia consists of 90% of desert-based aquaculture production in Egypt. Red tilapia are said to be preferred by consumers as their red coloration is appealing, as they resemble red colored marine fish such as coral cod (

Epinephelinae Groupers are a diverse group of marine Actinopterygii, ray-finned fish in the family Epinephelidae, in the order Perciformes. Groupers were long considered a subfamily of the seabasses in Serranidae, but are now treated as distinct. Not all m ...

) or rockfish (

Sebastinae Sebastinae is a subfamily of marine fish belonging to the Family (biology), family Scorpaenidae in the Order (biology), order Scorpaeniformes. Their common names include rockfishes, rock perches, ocean perches, sea perches, thornyheads, scorpion ...

) which are highly valued. Additionally the flavor of their meat is less "

off Off or OFF may refer to: Art and entertainment * ''Off'' (video game), a video game by Mortis Ghost. *Sven Väth, German DJ and singer who uses the pseudonym OFF * ''Off'' (album), by Ciwan Haco, 2006 * ''Off!'' (album), by Off! * Off!, an Ameri ...

" or muddy-flavored when raised in saltwater, which is possible with hybrids descended from ''O. mossambicus''. The FDA outlaws the sale of steroid-treated tilapia in the United States. SeafoodWatch (a program maintained by the

Monterey Bay Aquarium Monterey Bay Aquarium is a Nonprofit organization, nonprofit public aquarium in Monterey, California. Known for its regional focus on the marine habitats of Monterey Bay, it was the first to exhibit a living kelp forest when it opened in Octob ...

) deems hybrid red tilapia raised in "indoor recirculating tanks with

wastewater treatment Wastewater treatment is a process which removes and eliminates contaminants from wastewater. It thus converts it into an effluent that can be returned to the water cycle. Once back in the water cycle, the effluent creates an acceptable impact on ...

" as a "Best Choice" seafood option, while those raised in outdoor ponds are rated as a "Good Alternative". A tilapia

fillet Fillet may refer to: *Annulet (architecture), part of a column capital, also called a fillet *Fillet (aircraft), a fairing smoothing the airflow at a joint between two components *Fillet (clothing), a headband *Fillet (heraldry), diminutive of the ...

represents about 30% of the fish, with the rest typically not consumed by humans.

Collagen Collagen () is the main structural protein in the extracellular matrix of the connective tissues of many animals. It is the most abundant protein in mammals, making up 25% to 35% of protein content. Amino acids are bound together to form a trip ...

can be extracted from tilapia skin, which is used in the

cosmetics Cosmetics are substances that are intended for application to the body for cleansing, beautifying, promoting attractiveness, or altering appearance. They are mixtures of chemical compounds derived from either Natural product, natural source ...

and pharmaceutical industries.

Environmental impact

Many ''Oreochromis'' species has been introduced to countries around the world, where they regularly establish breeding populations in suitable habitats (

tropical The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

waterways with adequate

salinity Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...

). The majority of species were transplanted to different areas relatively close to their native territory (i;e to other African countries), with comparatively few species being introduced to Asian and

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

waterways, including Taiwan red tilapia. ''O. mossambicus'' is claimed to represent the "earliest international movements of tilapiine cichlids", with a recorded appearance in

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

from before 1939 (local name: ''mujair'', taken from Mbah Moedjair's name). Tilapia (reported as ''O. mossambicus'') are on the

IUCN The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...

's list of the 100 Worst Alien/

Invasive Species An invasive species is an introduced species that harms its new environment. Invasive species adversely affect habitats and bioregions, causing ecological, environmental, and/or economic damage. The term can also be used for native spec ...

in the World. Originally introduced as a protein source for impoverished rural communities, to improve fishery stocks, to provide live bait for

tuna fishing A tuna (: tunas or tuna) is a saltwater fish that belongs to the tribe Thunnini, a subgrouping of the Scombridae (mackerel) family. The Thunnini comprise 15 species across five genera, the sizes of which vary greatly, ranging from the bulle ...

, as a

biocontrol Biological control or biocontrol is a method of pest control, controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or phytopathology, plants by bioeffector, using other organisms. It relies o ...

agent to control aquatic weeds and

mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...

es, and for aquaculture, various tilapia species have since been naturalized in waterways of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

and Neotropical regions. In the United States, tilapia of both wild species and hybrids are well recorded as being established, especially in the Southern states,

Hawai'i Hawaii ( ; ) is an island state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two non-contiguous U.S. states (along with Alaska), it is the only state not on the North American mainland, th ...

, Puerto Rico, and

Guam Guam ( ; ) is an island that is an Territories of the United States, organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. Guam's capital is Hagåtña, Guam, Hagåtña, and the most ...

Saipan Saipan () is the largest island and capital of the Northern Mariana Islands, an unincorporated Territories of the United States, territory of the United States in the western Pacific Ocean. According to 2020 estimates by the United States Cens ...

. Overall, tilapia have been introduced to 85 countries as of 2013; in 58% of these countries tilapias are established, and cause adverse ecological effects in 14%. Salton Sea Tilapia

Floating cage aquaculture is deemed to have an "inevitable" chance of fish escaping. Escaped tilapia, which may reproduce prolifically, are thought to compete with native species for food and space, predate on their eggs and young, destroys submerged vegetation, reduces the abundance of planktonic micro-

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, reduces

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

through

bioturbation Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a ...

, and when present in large numbers risks

eutrophication Eutrophication is a general term describing a process in which nutrients accumulate in a body of water, resulting in an increased growth of organisms that may deplete the oxygen in the water; ie. the process of too many plants growing on the s ...

, all of which endangers the native ecosystem's integrity. Large tilapia populations in a non-flowing waterway has been consistently linked to

algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term ''algae'' encompass ...

s, which subsequently cause

fish kill The term fish kill, known also as fish die-off, refers to a localized mass mortality event, mass die-off of fish populations which may also be associated with more generalized mortality of aquatic life.University of Florida. Gainesville, FL (200 ...

events that kill all animals in the waterway. In African countries, such as

DR Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...

, Tanzania, and Nigeria, non-native tilapia species/subspecies may contribute their genes into the native species, which may put populations and genetics of

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

species at risk. In the Pearl River Basin, South China, Nile tilapia were found to disrupt the

trophic level The trophic level of an organism is the position it occupies in a food web. Within a food web, a food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the ...

s of native herbivorous and planktivorous fish by forcing them to feed on alternate food sources, as they were outcompeted and food resources decreased in abundance. Consequently, local abundance of mudcarp ('' Cirrhinus molitorella''), black bream ('' Megalobrama terminalis''), barbel chub (''

Squaliobarbus curriculus The barbel chub (''Squaliobarbus curriculus'') is a species of freshwater ray-finned fish belonging to the family Xenocyprididae/ which is found in China, North Korea, South Korea, eastern Russia, and Vietnam Vietnam, officially the Soc ...

''), and sawbelly ('' Hemiculter leucisculus'') all decreased significantly, despite previously being the dominant species caught in these rivers. Additionally, the body condition of these native fish, such as "plumpness" (girth), body length, and body weight, all decreased in rivers with introduced tilapia. In

Acari Mites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as ea ...

, Brazil, catches of croaker ('' Plagioscion squamosissimus''), curimatã ('' Prochilodus brevis''), and traíra (''

Hoplias malabaricus ''Hoplias malabaricus'', also known as the wolf fish, tiger fish, guabine or trahira, is a predatory Central and South American freshwater ray-finned fish of the characiform family Erythrinidae. Description The maximum known length for this ...

'') were recorded to decrease in the 30 years after tilapia were introduced in a reservoir, without a decrease in CPUE (catch-per-unit-of-effort; amount of effort done to land fish). Additionally, it is believed that introduced tilapia has had ecological effects in the

Kafue Kafue is a town on the T2 road in the Lusaka Province of Zambia and it lies on the north bank of the Kafue River, after which it is named. It is the southern gateway to the central Zambian plateau on which Lusaka and the mining towns of Kabwe ...

and

Zambezi basin The Zambezi basin is an African drainage basin, whose main flow is the Zambezi River, being the fourth largest basin on the continent, in addition to being the most important basin in southern Africa. It covers approximately 1,390,000 km², c ...

s, Australia, Madagascar, Nicaragua, the Philippines, and Mexico. Species endemic to these waterways, such as Madagascar's endemic ichthyofauna and the relict populations of wild

axolotl The axolotl (; from ) (''Ambystoma mexicanum'') is a neoteny, paedomorphic salamander, one that Sexual maturity, matures without undergoing metamorphosis into the terrestrial adult form; adults remain Aquatic animal, fully aquatic with obvio ...

, are likely to be impacted by tilapia introductions. As tilapia reproduce prolifically, it is almost impossible to remove them from an ecosystem once established, and methods that may prove effective risks destroying native species as well. Tightening

biosecurity Biosecurity refers to measures aimed at preventing the introduction or spread of harmful organisms (e.g. viruses, bacteria, plants, animals etc.) intentionally or unintentionally outside their native range or within new environments. In agricult ...

measures and

regulation Regulation is the management of complex systems according to a set of rules and trends. In systems theory, these types of rules exist in various fields of biology and society, but the term has slightly different meanings according to context. Fo ...

s in aquaculture operations is hoped to provide some relief.

References

{{Taxonbar, from=Q133752049 Fish hybrids Oreochromis