Oreochromis mossambicus
From Wikipedia, the free encyclopedia
The
Mozambique tilapia,
Oreochromis mossambicus, is a
tilapiine cichlid fish native to southern Africa. It is a popular fish for
aquaculture. It is now found in tropical and subtropical habitats around the globe, where it can become an
invasive species. It is known as
Blue Kurper in
South Africa.
[1]
Description
The native Mozambique tilapia is laterally compressed, and has a deep
body with long dorsal fins, the front part of which have spines. Native
coloration is a dull greenish or yellowish, and there may be weak
banding. Adults reach approximately 35 centimetres (14 in) in length and
up to 1.13 kilograms (2.5 lb). Size and coloration may vary in captive
and naturalized populations due to environmental and breeding pressures.
It lives for up to 11 years.
It is a remarkably robust and fecund fish, readily adapting to
available food sources and breeding under suboptimal conditions. It also
tolerates brackish water and survives temperatures below
50 °F (10 °C) and above
100 °F (38 °C).
Home Range
The Mozambique tilapia is native to coastal regions and the lower reaches of rivers in southern Africa, from the
Zambezi River delta to
Bushman River in the eastern Cape.
[1] It is threatened in its home range by competition with the invasive
Nile tilapia (Waal 2002).
Diet
Mozambique tilapia are omnivorous. They can consume detrital
material, diatoms, invertebrates, small fry and vegetation ranging from
macroalgae to rooted plants (Mook 1983, Trewevas 1983). This broad diet
helps the species thrive in diverse locations.
Invasiveness
The Mozambique tilapia is an
invasive species
in many parts of the world, having escaped from aquaculture or been
deliberately introduced to control mosquitoes (Moyle 1976). It has been
nominated by the Invasive Species Specialist Group (ISSG) as one the 100
worst invasive species in the world (Courtenay 1989). It can harm
native fish populations through competition for food and nesting space,
as well as by directly consuming small fish (Courtenay et al. 1974). In
Hawaii, striped mullet
Mugil cephalus
are threatened because of the introduction of this species. Mozambique
tilapia may also be responsible for the decline of the desert pupfish,
Cyprinodon macularius, in California's Salton Sea (Courtenay and Robins 1989, Swift et al. 1993).
Hybridization
As with most species of tilapia, Mozambique tilapia have a high potential for
hybridization.
They are often crossbred with other tilapia species in aquaculture
because purebred Mozambique tilapia grow slowly and have a body shape
poorly suited to cutting large
fillets. Also, hybrids between certain parent combinations (such as between Mozambique and
Wami tilapia)
result in offspring that are all or predominantly male. Male tilapia
are preferred in aquaculture as they grow faster and have a more uniform
adult size than females. The "Florida Red" tilapia is popular
commercial hybrid of Mozambique and
Blue tilapia.
[2]
Reproduction
In the first step in the reproductive cycle for Mozambique tilapia,
males excavate a nest into which a female can lay her eggs. After the
eggs are laid the male fertilizes them. Then the female stores the eggs
in her mouth, called
mouthbrooding, until the fry hatch (Popma, 1999).
Use in aquaculture
Mozambique tilapia are hardy individuals that are easy to raise and
harvest, making them a good aquacultural species. They have a mild,
white flesh that is appealing to consumers. This species constitutes
about 4% of the total tilapia aquaculture production worldwide, but is
more commonly hybridized with other tilapia species (Gupta and Acosta
2004). Tilapia are very susceptible to diseases such as
whirling disease and
ich (Popma, 1999).
Other names
The species is known by a number of other names including
0 komentar:
Posting Komentar