Species of fish

The Mozambique tilapia ( Oreochromis mossambicus ) is an oreochromine cichlid fish native to southeastern Africa. Dull colored, the Mozambique tilapia often lives up to a ten in its native habitats. It is a democratic fish for aquaculture. Due to human introductions, it is now found in many tropical and subtropical habitats around the ball, where it can become an invasive species because of its robust nature. These lapp features make it a good species for aquaculture because it readily adapts to fresh situations. It is known as black tilapia in Colombia [ 2 ] and as blue kurper in South Africa. [ 3 ]

description [edit ]

The native Mozambique tilapia is laterally compressed, and has a deep body with farseeing dorsal fins, the front function of which have spines. native coloration is a dense green or yellow, and fallible ring may be seen. Adults reach up to 39 centimeter ( 15 in ) in standard distance and astir to 1.1 kg ( 2.4 pound ). [ 4 ] Size and coloration may vary in captive and domesticate populations ascribable to environmental and breed pressures. It lives up to 11 years. [ 4 ]

distribution and habitat [edit ]

An pornographic male in breeding condition The Mozambique tilapia is native to inland and coastal waters in southeastern Africa, from the Zambezi basin in Mozambique, Malawi, Zambia and Zimbabwe to Bushman River in South Africa ‘s Eastern Cape province. [ 1 ] [ 5 ] It is threatened in its home range by the introduced Nile tilapia. In addition to competing for the same resources, the two promptly hybridize. [ 1 ] [ 6 ] This has already been documented from the Zambezi and Limpopo Rivers, and it is expected that pure Mozambique tilapia finally will disappear from both. [ 1 ] Otherwise it is a signally robust and fecund pisces, promptly adapting to available food sources and breeding under suboptimal conditions. Among others, it occurs in rivers, streams, canals, ponds, lakes, swamps and estuaries, although it typically avoids fast-flowing waters, waters at high altitudes and the open sea. [ 1 ] [ 4 ] It inhabits waters that range from 17 to 35 °C ( 63–95 °F ). [ 4 ] [ 7 ]

Invasiveness [edit ]

The Mozambique tilapia or hybrids involving this species and other tilapia are incursive in many parts of the universe outside their native range, having escaped from aquaculture or been intentionally introduced to control mosquitoes. [ 8 ] The Mozambique tilapia has been nominated by the Invasive Species Specialist Group as one of the 100 worst invasive species in the earth. [ 9 ] It can harm native fish populations through competition for food and nest space, ampere well as by directly consuming little pisces. [ 10 ] In Hawaii, striped mullet Mugil cephalus are threatened because of the introduction of this species. The population of hybrid Mozambique tilapia x Wami tilapia in California ‘s Salton Sea may besides be responsible for the decline of the desert pupfish, Cyprinodon macularius. [ 11 ] [ 12 ] [ 13 ]

hybridization [edit ]

As with most species of tilapia, Mozambique tilapia have a high likely for hybridization. They are often crossbred with early tilapia species in aquaculture because purebred Mozambique tilapia grow lento and have a torso form ailing suited to cutting large fillets. however, Mozambique tilapia have the desirable trait of being specially kind of piquant water system. [ 14 ] besides, hybrids between certain parent combinations ( such as between Mozambique and Wami tilapia ) solution 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 a democratic commercial hybrid of Mozambique and blue tilapia. [ 15 ]

demeanor [edit ]

Feeding [edit ]

Mozambique tilapia are omnivorous. They can consume debris, diatoms, invertebrates, little fry and vegetation ranging from macroalgae to rooted plants. [ 16 ] [ 17 ] This broad diet helps the species thrive in diverse locations. due to their robust nature, Mozambique tilapia often over-colonize the habitat around them, finally becoming the most abundant species in a especial area. When congestion happens and resources get scarce, adults will sometimes cannibalize the youthful for more nutrients. Mozambique tilapia, like early fish such as Nile tilapia and trout, are opportunist omnivores and will feed on alga, plant matter, organic particles, little invertebrates and other pisces. [ 18 ] Feeding patterns vary depending on which food source is the most abundant and the most accessible at the fourth dimension. In captivity, Mozambique tilapias have been known to learn how to feed themselves using requirement feeders. During commercial feed, the fish may energetically jump out of the water for food. [ 19 ]

social structure [edit ]

Mozambique tilapias frequently travel in groups where a rigorous dominance hierarchy is maintained. Positions within the hierarchy correlative with territoriality, courtship pace, nest size, aggression, and hormone production. [ 20 ] In terms of social structure, Mozambique tilapias absorb in a arrangement known as lek-breeding, where males establish territories with dominance hierarchies while females travel between them. Social hierarchies typically develop because of competition for express resources including food, territories, or mates. During the breed season, males cluster around certain territory, forming a dense collection in shallow water. [ 21 ] This collection forms the basis of the lek through which the females preferentially choose their mates. generative achiever by males within the lek is highly correlated to social status and dominance. [ 22 ] In experiments with captive tilapia, evidence demonstrates the formation of linear hierarchies where the alpha male participates in significantly more agonistic interactions. frankincense, males that are higher rank initiate much more aggressive acts than dependent males. however, contrary to popular impression, Mozambique tilapias display more agonistic interactions towards fish that are far apart in the hierarchy plate than they do towards individuals closer in rank. One hypothesis behind this action rests with the fact that aggressive actions are dearly-won. In this context, members of this social organization tend to avoid confrontations with neighboring ranks in decree to conserve resources rather than engage in an unclear and bad fight. alternatively, prevailing individuals seek to browbeat subordinate tilapias both for an easy fight and to keep their social station. [ 23 ]

communication and aggression [edit ]

urine in Mozambique tilapia, like many freshwater fish species, acts as a vector for communication amongst individuals. Hormones and pheromones released with urine by the fish much affect the behavior and physiology of the opposite sex. dominant allele males bespeak females through the use of a urinary odorant. further studies have suggested that females respond to the proportion of chemicals within the urine, as opposed to the smell itself. however, females are known to be able to distinguish between hierarchical rank and dominant vs. subordinate males through chemicals in urine. urinary pheromones besides play a region in male – male interaction for Mozambique tilapia. Studies have shown that male aggression is highly correlated with increased micturition. harmonious aggression between males resulted in an increase in the release of micturition frequency. dominant males both store and release more potent urine during agonistic interactions. thus, both the initial stage of lek formation and the alimony of social hierarchy may highly depend on the males ’ varying urinary output. [ 24 ]

Aggression amongst males normally involve a typical succession of ocular, acoustic, and tactile signals that finally escalates to forcible confrontation if no resolution is reached. normally, conflict ends before physical aggression as fights are both dearly-won and hazardous. Bodily damage may impede an individual ‘s ability to find a checkmate in the future. In ordering to prevent cheat, in which person may fake his own fitness, these aggressive rituals incur significant energetic costs. frankincense, cheating is prevented by the swerve fact that the costs of initiating a ritual often outweigh the benefits of cheating. In this regard, differences between individuals in endurance plays a critical role in resolving the achiever and the loser. [ 25 ]

reproduction [edit ]

In the beginning measure in the generative 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 talk until the fry hatch ; this act is called mouthbrooding. [ 26 ] One of the main reasons behind the aggressive actions of Mozambique tilapia is access to reproductive mates. The designation of Mozambique tilapia as an invasive species rests on their life-history traits : Tilapias exhibit high levels of parental manage a well as the capacity to spawn multiple broods through an extend generative season, both contributing to their success in varying environments. [ 27 ] In the lek system, males congregate and display themselves to attract females for matings. thus, mating success is highly skew towards dominant allele males, who tend to be larger, more aggressive, and more effective at defending territories. dominant males besides build larger nests for the engender. [ 21 ] During courtship rituals, acoustic communication is widely used by the males to attract females. Studies have shown that females are attracted to dominant males who produce lower peak frequencies equally well as higher pulse rates. At the end of entangle, males guard the nest while females take both the eggs and the sperm into their mouth. due to this, Mozambique tilapia can occupy many niches during spawning since the young can be transported in the mouth. [ 28 ] These technical generative strategies may be the induce behind their invasive tendencies. male Mozambique tilapia synchronize breeding behavior in terms of courtship activity and territoriality in order to take advantage of female spawning synchronism. One of the costs associated with this synchronization is the increase in competition among males, which are already high on the dominance hierarchy. As a solution, different mating tactics have evolved in these species. Males may mimic females and sneak reproduction attempts when the dominant male is occupied. Likewise, another strategy for males is to exist as a vagrant, travelling between territories in an undertake to find a teammate. however, it is the dominant males who have the greatest generative advantage. [ 29 ]

Parental concern [edit ]

typically, Mozambique tilapia, like all species belonging to the genus Oreochromis and species like Astatotilapia burtoni, are maternal mouthbrooders, meaning that spawn is incubated and raised in the mouth of the mother. Parental care is, consequently, about exclusive to the female. Males do contribute by providing nests for the spawn before incubation, but the department of energy costs associated with nest production is low relative to mouthbrooding. Compared to nonmouthbrooders, both mouthbrooding and growing a new clutch bag of eggs is not energetically feasible. thus, Mozambique tilapias arrest oocyte growth during mouthbrooding to conserve energy. [ 30 ] tied with oocyte collar, females that mouthbrood take significant costs in body weight, energy, and low fitness. Hence, parental-offspring conflict is visible through the costs and benefits to the parents and the young. A mother caring for her young carries the cost of reducing her own person fitness. Unlike most fish, Mozambique tilapias exhibit an extend maternal wish period believed to allow social bonds to be formed. [ 31 ]

Use in aquaculture [edit ]

An albino tenor has been developed in enslavement Mozambique tilapia are audacious individuals that are easy to raise and harvest, making them a good aquicultural species. They have a mild, egg white human body that is appealing to consumers. This species constitutes about 4 % of the total tilapia aquaculture production global, but is more normally hybridized with other tilapia species. [ 32 ] Tilapia are very susceptible to diseases such as whirling disease and ich. [ 26 ] Mozambique tilapia are insubordinate to wide varieties of water choice issues and befoulment levels. Because of these abilities they have been used as bioassay organisms to generate metallic perniciousness data for hazard assessments of local fresh water species in South Africa rivers. [ 33 ]

early names [edit ]

The species is known by a number of other names including :

  • Mujair in Indonesia
  • Daya in Pakistan

References [edit ]

References [edit ]

  • “Oreochromis mossambicus”. Integrated Taxonomic Information System .
  • 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, D.C.
  • 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; Herrema, D.J. (1974). “Exotic fishes in fresh and brackish waters of Florida”. Biological Conservation. 6 (4): 292–302. doi:10.1016/0006-3207(74)90008-1.
  • 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.
  • Mook, D (1983). “Responses of common fouling organisms in the Indian River, Florida, to various predation and disturbance intensities”. Estuaries. 6 (4): 372–379. doi:10.2307/1351396. JSTOR 1351396. S2CID 87151335.

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  • Moyle P.B. 1976. Inland fishes of California. University of California Press, Berkeley, CA. 330 p.
  • Popma, T. Tilapia Life History and Biology 1999 Southern Region Aquaculture Center
  • Swift, C.C.; Haglund, T.R.; Ruiz, M.; Fisher, R.N. (1993). “The status and distribution of the freshwater fishes of southern California”. Bulletin of the Southern California Academy of Science. 92: 101–167.
  • 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.
  • Photo of “Florida Red” hybrid. Retrieved 12 July 2007.

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