Thursday, September 18, 2008

Tilapia

Tilapia is the for nearly a hundred species of cichlid fishes from the tilapiine cichlid . Tilapias inhabit a variety of and, less commonly, brackish water habitats from shallow streams and ponds through to rivers, lakes, and estuaries. Most tilapias are with a preference for soft aquatic vegetation and detritus. They have historically been of major importance in in Africa and the Levant, and are of increasing importance in aquaculture around the world . Where tilapia have been deliberately or accidentally , they have frequently become problematic invasive species .

Etymology


The common name tilapia is based on the name of the genus '''', which is itself a latinisation of ''thiape'', the word for "fish". The genus name and term was first introduced by zoologist in 1840.

As they have been introduced globally for human consumption , tilapia often have specific names for them 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 about the apostle 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 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 in the area for thousands of years. In some Asian countries including the Philippines, large tilapia are often referred to as ''pla-pla'' while their smaller brethren are still referred to as ''tilapia''. In Hebrew, tilapia are called ''amnoon'' . In Arabic, tilapia are called ''bolty'' .

Aquaculture




Tilapia has become the third most important fish in aquaculture after carps and s, 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 . 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, and Indonesia. 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.

Non-indigenous populations



Tilapia have been used as biological controls for certain aquatic plant problems. They prefer a floating aquatic plant, duckweed but also consume some filamentous alga . In Kenya tilapia were introduced to which were causing malaria. They consume mosquito larvae, consequently reducing the numbers of adult female mosquitoes, the of the disease . These benefits are, however, frequently outweighed by the negative aspects of tilapia as invasive species. In Kenya the Tilapia found in Lake Victoria , is referred to as Ngege by the Luo. Its export to the European market has threatened its availability to the Luos who consider it a staple food.

Aquaria



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, , , garpike, and other robust but peaceful fish. Some species, including ''Tilapia buttikoferi'', ''Tilapia rendalli'', ''Tilapia joka'', and the brackish-water '''', are attractively patterned and decorative fish.

Bibliography



*
* : Interactions between fish and aquatic macrophytes in inland waters. A review. ''FAO Fisheries Technical Papers'' 396.
* : ''Tilapiine fishes of the genera ''Sarotherodon'', ''Oreochromis'' and ''Danakilia. Published by the British Museum , London. 583 pages. ISBN 0-565-00878-1