Oreochromis mossambicus

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Mozambique Tilapia

Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Cichlidae
Genus: Oreochromis
Species: O. mossambicus
Binomial name
Oreochromis mossambicus
(Peters, 1852)

Provided is a link that differentiates the Nile Tilapia from the Mozambique [1]

Contents

[edit] Morphology

The Mozambique tilapia is laterally compressed, and has a deep body with long dorsal fins. The front part of the dorsal fin is the most inconvenient to handle because it has spines on it. Looking at the coloration and patterns of the Mozambique tilapia specifically, it has weak banding (Popma, 1999). The main coloration is yellow, though coloration is unreliable due to the many different colors of cichlid fish and the many different feeding strategies (Popma, 1999).

[edit] Home Range

The Mozambique tilapia, Oreochromis mossambicus, is an African tilapiine cichlid fish. It is widely used as food and has been introduced in various localities for aquaculture, and may be (erroneously) called "Java tilapia" in trade. Centers of abundance in Florida include rivers and counties alike. Courtney et al. (1974) According to Science in Africa, the Mozambique occurs naturally above in the Lapopo River.

[edit] Ecology

The Mozambique are omnivores that consume detrital material,vegetation with various ranges from diatoms to macroalgae to rooted plants, invertebrates, and small fry(Bowen 1979, Mook 1983, Trewevas 1983). This is mainly why they were introduced. Diets vary depending on location. Oreochromis mossambicus co-occurs with a number of other non-native tilapia species in many of the states that have this Tilapia in them. They were released for the control of mosquitoes But failed to grow stabilize populations and became a nuisance (Moyle, 1976).

[edit] Is it an invasive species?

In some such places, it has escaped captivity and proliferated excessively, becoming an invasive species (see Tilapia as exotic species). Also they were first found in Texas, Florida, and Alabama. According to an article in science in Africa the Mozambique is being endangered by the Nile Tilapia (Waal,2002). In all other parts of the world the Mozambique is being identified as a nuisance. Oreochromis mossambicus has been nominated by the Invasive Species Specialist Group (ISSG) as among "100 of the World's worst" invasive alien species (Courtenay, 1989). They have been introduced for sport fishing and their numbers haven't acquired enough stability to do damges to the ecosystem. The fish that they effect are other natives as well as other Tilapia. Oreochromis mossambicus pose threats to local native populations through competition for food and nesting space (Courtenay et al. 1974). This interaction may reduce the biodiversity of the native fishery due to reduction of food availability and by the native fish being eaten as prey for example the larval stages (Neil 1966, Bruton and Boltt 1975). 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).

[edit] Feeding Strategies

The feeding strategies for the Mozambique tilapia include plankton, and aquatic invertebrates, and decomposing organic matter. They are considered filter feeders because they can literally filter plankton out of the water. This can be done by the mucous secreted by the tilapias that trap the plankton (Popma, 1999). Digestion of the plankton is started by the grinding of the food between two pharyngeal plates. The pH level of these fish’s stomach is around 2 which burst the cells of the plankton (Popma, 1999).

[edit] Hybridization

Its relationships are somewhat unclear — as with most tilapias — due to their large potential of producing fertile hybrids. This hampers studies based on mtDNA. Nuclear DNA on the other hand evolves too slowly to resolve the relationships of tilapias properly in most cases. Also, morphology is highly plastic in this group. Notwithstanding this uncertainty, it seems that Oreochromis amphimelas, Oreochromis malagarasi and Oreochromis karongae are among the species most closely related to the Mozambique tilapia.(Nagl et al. 2001)

The potential to hybridize is utilized in aquaculture. Purebred Mozambique tilapia are not considered ideal today because they grow slowly and have a body shape less suited to cutting large fillets; they are however highly tolerant of brackish water[2]. Hybrids between certain parent combinations (such as between Mozambique and Wami tilapia) will 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 which has Mozambique and Blue tilapias as parents.[3]

[edit] Reproduction

Reproduction strategy doesn’t vary within the cichlid family. The male takes the time to excavate a nest, the female then lays her eggs. After the eggs are laid the male fertilizes them. The female then takes the eggs and stores them in her mouth until the fry hatch (Popma, 1999).

[edit] Aquacultural settings

In aquaculture tilapias thrive. Mozambique tilapia are hardy individuals that are easy to grow, which makes them an ideal aquaculture species. Tilapia have a mild, white flesh that sustains them for they don’t travel like salmon and this appeals to consumers, making them economically important as a fish food source. This species contributes about 4% of the total tilapia aquaculture production worldwide, and is valued more when used for hybridization (Gupta and Acosta 2004). They are very easy to harvest and very easy to replenish. The downside is that the tilapia is very susceptible to diseases. These diseases may include whirling disease and ich (Popma, 1999). The whirling disease is where a fish continues to swim in a circle and ich is a bacterial infection that is shown as white spots on the fish’s body usually from stress.

[edit] Economics

The economic impact of the Tilapia include 17 million pounds with an expect growth rate in which has helped Asian countries and in the united states there has been an increase since 1997 that say the US consumes more than 100 million pounds annually. The total retail sale of tilapia was higher than trout in 1996 and 1997 (Holland 1999).


[edit] Conservation Status

According to the article in science in africa, the Mozambique tilapia is being threatened by the Nile tilapia. Both fish species show similar feeding, breeding, growth and behavioural patterns.They are allopatric in distribution where complete separation has not yet occurred. When the transition of one species into the others habitat occurs the threat of hybrids can occur being in the same species. Never having occurred together in earlier years, both the Nile and the Mozambique had no strategies to evolve from producing hybrids. Thus they created hybrid offspring through mating.

[edit] See also

[edit] References

Wikimedia Commons has media related to:

Courtenay W.R., Jr. 1989. Exotic fishes in the National Park System. Pages 237-252 in: Thomas L.K. (Ed) . Proceedings of the 1986 conference on science in the national parks, volume 5. Management of exotic species in natural communities. U.S. National Park Service and George Wright Society, Washington, DC.

Bruton M.N., and B.R. Allanson. 1974. The growth of Tilapia mossambica Peters (Pisces: Cichlidae) in Lake Sibaya, South Africa. Journal of Fish Biology 6:701-715.

http://www.sms.si.edu/irlspec/Oreochromis_mossambicus.htm


Brown W. H. 1961. First Record Of The African Mouthbreeder Tilapia Mossambica Peters In Texas. Texas Journal of Science 13:352-354.

Bruton M.N., and R.E. Boltt. 1975. Aspects of the biology of Tilapia mossambica Peters (Pisces: Cichlidae) in a natural freshwater lake (Lake Sibaya, South Africa). Journal of Fish Biology 7:423-445.

Courtenay W.R., Jr., and C.R. Robins. 1989. Fish introductions: Good management, mismanagement, or no management? CRC Critical Reviews in Aquatic Sciences 1:159-172.

Courtenay W.R., Jr., Sahlman H.F, Miley W.W., II, and D.J. Herrema. 1974. Exotic fishes in fresh and brackish waters of Florida. Biological Conservation 6:292-302.

Gupta M.V. and B.O. Acosta. 2004. A review of global tilapia farming practices. WorldFish Center P.O. Box 500 GPO, 10670, Penang, Malaysia.

Holland, Rob. Hill, Tom. Wolfe, Kent. 1999 Economic Concerns for Tilapia Enterprises.

Lee D.S., Gilbert C.R., Hocutt C.H., Jenkins R.E., McAllister D.E., and J.R. Stauffer, Jr. 1980. Atlas of North American Freshwater Fishes. North Carolina State Museum of Natural History, Raleigh, NC. 854 p.

Mook D. 1983. Responses of common fouling organisms in the Indian River, Florida, to various predation and disturbance intensities. Estuaries 6:372-379.

Moyle P.B. 1976. Inland fishes of California. University of California Press, Berkeley, CA. 330 p.

Neil E.H. 1966. Observations on the behavior of Tilapia mossambica (Pisces, Cichlidae) in Hawaiian ponds. Copeia 1966:50-56.

Popma, T. Tilapia Life History and Biology 1999 Southern Region Aquaculture Center

Publication #283. http://aquanic.org/publicat/usda_rac/efs/srac/283fs.pdf

Riedel R., and B.A. Costa-Pierce. 2005. Feeding ecology of Salton Sea Tilapia (Oreochromis spp.). Bulletin of the Southern California Academy of Sciences 104:26-36.

Swift C.C., Haglund T.R., Ruiz M., and R.N. Fisher. 1993. The status and distribution of the freshwater fishes of southern California. Bulletin of the Southern California Academy of Science 92:101-167.

Tilmant, J.T. 1999. Management of nonindigenous aquatic fish in the U.S. National Park System. National Park Service. 50 p. Economic Consequences.

Trewevas E. 1983. Tilapiine Fishes Of The Genera Sarotherodon, Oreochromis And Danakilia. British Museum Of Natural History, Publication Number 878.Comstock Publishing Associates. Ithaca, New York. 583 p.

Waal, Ben van der, 2002. Another fish on its way to extinction? Science in Africa. http://www.scienceinafrica.co.za/2002/january/tilapia.htm

[edit] External links

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