Fish

Tilapia

Oreochromis and relatives · also called tilapias, St Peter's fish

Least Concern → omnivoreherbivore Rivers & wetlands Coasts & shorelines

A tilapia is an African lake fish that turned out to be almost perfectly built for farming: it grows fast, eats algae and cheap plant pellets rather than other fish, shrugs off crowding and warm murky water, breeds without help, and tastes mild. That combination has made it one of the most produced and most eaten fish on the planet — and, where it has escaped, one of the most troublesome invaders.

Overview

Tilapias are a group of African cichlids, chiefly the genus Oreochromis, native to rivers, lakes, floodplains, and lagoons across Africa and the Levant. They are omnivores feeding low on the food web — algae, plants, plankton, and detritus — which is the key to farming them cheaply. Many are mouthbrooders: a parent carries the eggs and fry in its mouth, taking them back in at any threat.

The farmed fish

Tilapia is the second or third most farmed fish in the world, over 6 million tonnes a year, grown across Asia, Africa, and the Americas. Because mixed-sex fish breed so fast that ponds fill with stunted stock, farms usually raise all-male batches. Tilapia have been eaten since ancient Egypt, and the Sea of Galilee species is traditionally “St Peter’s fish”.

The invader

Spread worldwide for aquaculture and weed control, escaped tilapia now live wild on every warm continent, where they graze plants to the roots, muddy the water, and eat the eggs of native fish. They are very hard to remove once established, and cold winters are their main limit.

Status

The farmed species are Least Concern and abundant. The concerns run the other way: introduced tilapia damage native fish communities, and some wild African tilapias with small ranges are themselves threatened by habitat loss and by hybridisation with escaped farmed fish.

Tilapia: common questions

Is tilapia a healthy fish to eat?

Tilapia is a lean, mild, low-mercury white fish that is a reasonable source of protein and is inexpensive, and for most people it is a perfectly healthy choice. It is lower in the omega-3 fatty acids EPA and DHA than oily fish like salmon, sardines, or mackerel, because it is a plant-eater rather than a fish-eater, so it is not a good option if you are specifically after omega-3s. Some older reports raised concerns about the omega-6 to omega-3 ratio in farmed tilapia, but the amounts of fat involved are small and mainstream nutrition advice does not single tilapia out as unhealthy. As with any farmed fish, quality varies by producer and country.

Why is tilapia farmed so widely?

Because it is close to an ideal aquaculture animal. Tilapia eat low on the food web, thriving on algae, plants, and cheap plant-based pellets rather than needing fishmeal made from wild-caught fish, which keeps feed costs and environmental impact down. They grow to market size in six to eight months, tolerate crowding, warm water, low oxygen, and brackish conditions that would stress most fish, resist common diseases, and breed easily so hatcheries can supply fry cheaply. This makes tilapia farming viable at every scale, from a backyard pond in a rural village to large industrial operations, and it has become a major source of affordable animal protein in the developing world.

Are tilapia invasive, and why are they a problem?

Yes, in most places they have been introduced. Tilapia were spread around the world for aquaculture, for weed and mosquito control, and as sport and aquarium fish, and populations that escaped or were released have become established across the warm regions of every inhabited continent. In their new ranges they graze aquatic vegetation to the roots, stir up sediment while feeding and nest-building so the water turns turbid, eat the eggs and fry of native fish, and outcompete local species for food and spawning sites, contributing to the decline of native fish in places such as Lake Nicaragua, parts of Australia, and many African lakes outside their natural range. Cold winters limit them in temperate regions, but climate warming is expanding where they can survive.

Why is tilapia called St Peter's fish?

The name refers to a passage in the Gospel of Matthew in which Jesus tells Peter to catch a fish, and Peter finds a coin in its mouth to pay the temple tax. Tilapia of the species Sarotherodon galilaeus are common in the Sea of Galilee, where the story is set, and because they are mouthbrooders that carry objects, including occasionally stones and shells, in their mouths, tradition identified them as the fish in the account. St Peter's fish is now a standard menu name for tilapia at restaurants around the Sea of Galilee and beyond, though the fish served may be any of several tilapia species.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 10, 2026. Last updated September 10, 2026.

Quick facts

Scientific name: Oreochromis and relatives
Diet: Mainly algae, aquatic plants, plankton, and organic detritus filtered and grazed from the water and bottom, along with small invertebrates, and it is this low position in the food web that makes tilapia so cheap and efficient to farm compared with carnivorous fish that need fishmeal
Mouthbrooding parents: In the farmed Oreochromis tilapias the female, and in some species the male, takes the fertilised eggs into the mouth and holds them there through hatching, releasing the fry to feed and taking them back in at any sign of danger, so a large part of the population is walking around with a mouthful of young
Among the most farmed fish on Earth: Tilapia is the second or third most produced farmed fish in the world after carp, with global aquaculture output of over 6 million tonnes a year, grown in ponds, cages, and tanks across Asia, Africa, and the Americas, with China, Egypt, and Indonesia the largest producers
Built to be farmed: Tilapia grow fast, tolerate crowding, low oxygen, and a wide range of salinity and water quality, breed readily, resist many diseases, and put on flesh efficiently on cheap plant-based feed, a combination that has made them the backbone of small-scale fish farming and food security projects in warm countries
An ancient food fish: Tilapia have been eaten in Africa and the Middle East for thousands of years, appearing in ancient Egyptian tomb paintings and pond-culture scenes, and the species Sarotherodon galilaeus of the Sea of Galilee is traditionally called St Peter's fish after the Gospel account of a coin found in a fish's mouth
An invasive problem: Escaped and released farmed tilapia, especially the Nile and Mozambique tilapias, have established wild populations across the warm parts of every continent except Antarctica, where they compete with and displace native fish, uproot aquatic plants, muddy the water, and prey on the eggs and young of other species
All-male farming and hybrids: Because mixed-sex tilapia breed so fast that ponds fill with stunted fish, commercial farms often stock only males, produced by hormone treatment of the fry, by crossing certain species to yield mostly male hybrids, or by using genetically all-male lines, so most tilapia sold has never had the chance to reproduce
Range: Native to fresh and brackish water across Africa, the Levant, and parts of the Middle East, in rivers, lakes, floodplains, and coastal lagoons, and introduced and now established in warm regions worldwide, including the southern United States, Mexico, Central and South America, southern and Southeast Asia, southern Europe, and Australia, wherever winter water temperatures stay above about 10 to 12 degrees Celsius.
Conservation status: Least Concern → ≈ The main farmed tilapia species are in no danger, being abundant in the wild, hugely produced in aquaculture, and further spread by introductions worldwide. The conservation concern is twofold and points the other way. First, introduced tilapia harm native freshwater fish and ecosystems in many countries and are very difficult to eradicate once established in warm water. Second, several of the wild tilapia and closely related cichlids native to specific African lakes and rivers are themselves threatened, by habitat loss, overfishing, and, in some cases, by hybridisation with introduced farmed tilapia that swamps the local gene pool in the wild