Invasive Species biology

8/13/2019 Invasive Species biology

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The Nile Perch generally grows between85 and 100 centimeters and weighsbetween 2 and 4 kilograms. However, thisfish has been captured and seen at a sizeof 210 centimeters and is able to reach aweight of 200 kilograms. It is one of the

most immense fresh water fish, and canlive for up to 16 years.


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The Nile Perch is native to a number offreshwater African lake and river systems.It was introduced to Lake Victoria in the

1950's.The Nile perch can also be found in otherAfrican river basins as:Chad, Senegal, Congo and Volta. They can

also be found in the Nile andLake Maryut in Egypt.


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As the fish isn't native from the area thelake's ecosystem was not prepared for it.Meanwhile the population of the fish wascontrolled through commercial fishing for

several years. The population exploded inlate 1980's.This massive grown up of the fishpopulation leaded to the extinction ornear extinction of several hundred nativespecies.


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The Nile perch is a dominating predatoryfish. They are able to inhabit both freshand tropical water. They become sexually

mature at the age of three years andreproduce in large numbers (they canproduce 16 million eggs at one time!!)

with juveniles requiring no parental care.


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The Nile perch is a fierce predator that has had a

devastating impact in its initial and introducedhabitats. They feed on their own species as wellas others, including crustaceans, mollusks andinsects.

As the fish matures its appetite increases. Thisimmense creature now searches for larger fishthan the usual minute supply. This ability to takeon different size fish enables it to dominate manyhabitats and have a catastrophic effect on themany species it encounters as it moves from areato area in search of food.


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The introduction of the Nile perch has had a significanteffect on the fishing industry. Not only has this speciesproduced an increase in complete fishery, it has alsohelped increase employment with fishery- related jobs

as well. Large factory fishing corporations haveprospered greatly due to the development of the Nileperch.


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The introduction of the Nile perch intoLake Victoria has had a catastrophic effecton the ecosystem. Hundreds of fish nativeto the lake have become extinct, by the

1980s, 300 of these fish were nonexistentThe Nile perch also carries numerousparasites in its gills and different areas ofits body, which can lead to the spread of

disease among other species resulting inthe loss of biodiversity.


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Due to their rapid reproduction anddominating force, according to the IUCNsInvasive Species Specialist group the NilePerch is considered one of the worlds

worst 100 invasive species. If dramaticmeasures are not taken to eliminate thisspecies, they will continue to cause

ecological disaster.


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Commercial fishing activities are currently the onlycontrol method for the Nile perch in LakeVictoria. Recently there have been signs of over

fishing. Over the past twenty years, the quantity of theNile perch caught in Lake Victoria as a percentage oftotal fish caught have slowly been declining. Theaverage size of the Nile perch has also declined over

this period. In addition, several species of fish thatwere killed by the introduction of the Nile perch intoLake Victoria are showing increasing populations.


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Invasive Species biology

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