The Tilapia

Mar 29, 2009 Features / Columnists, Interesting Creatures in Guyana

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Tilapia is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapias inhabit a variety of fresh and, less commonly, brackish water habitats from shallow streams and ponds through to rivers, lakes, and estuaries.
Most tilapias are omnivorous with a preference for soft aquatic vegetation and detritus. They have historically been of major importance in artisanal fishing in Africa and the Levant, and are of increasing importance in aquaculture around the world.

According to some reports wherever tilapias have been deliberately or accidentally introduced, they have frequently become problematic invasive species.
The common name tilapia is based on the name of the cichlid genus Tilapia, which is itself a latinisation of thiape, the Tswana word for “fish”. The genus name and term was first introduced by Scottish zoologist Andrew Smith in 1840.

As they have been introduced globally for human consumption, tilapias often are referred to by specific names in various languages and dialects. Certain species of tilapia are sometimes called “St. Peter’s fish.” This term is taken from the account in the Bible about the apostle Peter catching a fish that carried a shekel coin in its mouth. However, no species of fish is named in that passage of the Bible.
While that name is also applied to Zeus faber, a marine fish not found in the area, one tilapia (Sarotherodon galilaeus galilaeus) is known to be found in Sea of Galilee where the account took place. This particular species is known to have been the target of small-scale artisanal fisheries in the area for thousands of years.

In some Asian countries including the Philippines, large tilapias are often referred to as pla-pla while their smaller brethren are still referred to as tilapia. In Hebrew, tilapias are called amnoon. In Arabic, tilapia are called mush (comb) because of its comb-like tail. It is called jilaebi in Tamil.
Tilapia has become the third most important fish in aquaculture after carps and salmonids, with production reaching 1,505,804 metric tons in 2002. Because of their large size, rapid growth, and palatability, a number of tilapiine cichlids are at 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. Originally, the majority of such fisheries were in Africa, but accidental and deliberate introductions of tilapia into freshwater lakes in Asia have led to outdoor aquaculturing projects in countries with a tropical climate such as Papua New Guinea, the Philippines, Indonesia and Guyana.
In temperate zone localities, tilapiine farming operations require energy to warm the water to the tropical temperatures these fish require. One method involves warming the water using waste heat from factories and power stations.

A Tilapia is said to have very low levels of mercury because it is a fast growing and short lived fish that mostly eats a vegetarian diet.
Farm raised tilapia have very low levels of omega-3, the primary fatty-acid nutrient doctors recommend when eating fish. Farm raised tilapia also has high levels of omega-6 fatty acids. A diet with a high ratio of omega-6 to omega-3 is suspected to cause inflammation, which can be dangerous for those with heart conditions.

It is not clear if this poor ratio of omega-6 to omega-3 is due to the inexpensive corn and/or soy based diets typically fed to farm raised Tilapia, the natural fatty acid levels of Tilapia, or a combination of the two that results in less than desirable fatty acid ratio levels.
These aquatic creatures have been used as biological controls for certain aquatic plant problems. They prefer a floating aquatic plant, duckweed, but also consume some filamentous algae. In Kenya, tilapia were introduced to control mosquitoes which were causing malaria. 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.

The larger tilapias are generally not viewed as good community aquarium fish because they eat plants and tend to be very disruptive, digging up the substrate and fighting with other fish. The smaller West African species, such as Tilapia joka, and those species from the crater lakes of Cameroon are, by contrast, relatively popular.

Conversely, in cichlid aquariums tilapias can be mixed well with non-territorial cichlids, armoured catfish, tinfoil barbs, garpike, and other robust but peaceful fish. Some species, including Tilapia buttikoferi, Tilapia rendalli, Tilapia joka, and the brackish-water Sarotherodon melanotheron, are attractively patterned and decorative fish.
(Source: The Wikipedia Online Encyclopedia)

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