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Brief Summary

    Mozambique tilapia: Brief Summary
    provided by wikipedia

    The Mozambique tilapia (Oreochromis mossambicus) is a tilapiine cichlid fish native to southern Africa. It is a popular fish for aquaculture. Dull colored, the Mozambique tilapia often lives up to a decade in its native habitats. Due to human introductions, it is now found in many tropical and subtropical habitats around the globe, where it can become an invasive species because of its robust nature. These same features make it a good species for aquaculture because it readily adapts to new situations. It is known as black tilapia in Colombia and as blue kurper in South Africa.

    Brief Summary
    provided by EOL authors
    Oreochromis mossambicus, commonly known as the Mozambique tilapia, blue or Kurper bream, and by many other common names, is a cichlid fish native to southern Africa. Because of its success as a food fish bred through aquaculture, O. mossambicus has been spread to tropical and subtropical countries around the world. This hardy fish tolerates wide water temperatures, has a broad, omnivorous diet, rears easily and its firm texture and mild taste make it very popular for eating. The Mozambique tilapia breeds quickly and is fecund; females protect and transport their young by mouthbrooding. Because it easily establishes itself outside of its native range O. mossambicus has become an impossible to irradicate invasive pest in many countries, damaging ecosystems and biodiversity and threatening native fish (for example the striped mullet Mugil cephalus in Hawai’i and the endangered desert pupfish Cyprinodon macularius in California’s Salton Sea. Oreochromis mossambicus (along with closely the related O. aureus, with which O. mossambicus easily hybridizes) is on the list of the world’s 100 worst invasive species put out by the Invasive Species Specialist Group. (Global Invasive Species Database, Invasive Species Specialist Group (ISSG); Nico 2012; Wikipedia 2011)

    Brief Summary
    provided by FAO species catalogs
    Freshwater and brackish water inhabitants. Lives in warm, weedy pools of sluggish stream, canals, and ponds. Is mainly diurnal.Occurs at temperatures ranging from 8º to 42º C.

    The female usually incubates the spawn; the male should be removed as soon after spawning as possible.

    May form schools.Omnivorous, feeds on almost anything from algae to insects but also crustaceans, and fishes.Can be reared under hypersaline conditions. Spawn all year around when kept in warm water (above 20º C).

Comprehensive Description

    Biology
    provided by Fishbase
    Adults thrive in standing waters (Ref. 7248, 12501). Inhabit reservoirs, rivers, creeks, drains, swamps and tidal creeks; commonly over mud bottoms, often in well-vegetated areas (Ref. 44894). Also found in warm weedy pools of sluggish streams, canals, and ponds (Ref. 5723). Most common in blind estuaries and coastal lakes (Ref. 32693), but usually absent from permanently open estuaries and open sea (Ref. 6465) and from fast-flowing waters (Ref. 7248, 12501). Normally not found at high altitudes (Ref. 6465). Able to survive extreme reduction of temporary water bodies (Ref. 2, 27445). Highly euryhaline (Ref. 2, 3, 23, 58, 61, 6465, 12501, 12522, 12524, 13337, 27445, 55352). Grow and reproduce in fresh-, brackish and seawater (Ref. 2, 21, 23, 61, 5214, 27445, 36683, 54362). Can be reared under hyper-saline conditions (Ref. 4537, 44894, 52307). Tolerate low dissolved oxygen levels (Ref. 3, 23, 6465) and can utilise atmospheric oxygen when water oxygen levels drop (Ref. 61, 6465). Mainly diurnal. May form schools (Ref. 3, 4537, 44894). Omnivorous (Ref. 21, 12524), feed mainly on algae and phytoplankton (Ref. 4537, 7248, 12501, 12522, 12524, 13337, 36683, 44894, 52307) but also take some zooplankton, small insects and their larvae (Ref. 4537, 7248, 12524, 13337, 44894, 52307), shrimps (Ref. 12524, 13337), earthworms (Ref. 12501) and aquatic macrophytes (Ref. 6465). Juveniles carnivorous/omnivorous, adults tend to be herbivorous or detritus feeders (Ref. 2, 6465, 13517). Large individuals have been reported to prey on small fishes (Ref. 2, 6465, 12501, 12522), and occasionally cannibalise their own young (Ref. 2, 6465). Exhibit considerable plasticity in their feeding habits (Ref. 6465, 13544) as well as in their reproductive biology (Ref. 13544). Polygamous (Ref. 12524, 13337), maternal mouthbrooder (Ref. 1, 5214, 12524, 13337). Reach sexual maturity at 15 centimeter length (Ref. 44894), but stunted fish may breed at 6-7 centimeters and at an age of just over 2 months (Ref. 52307). Fecundity high (Ref. 55352). Extended temperature range 8-42 °C, natural temperature range 17-35°C (Ref. 3), with salinity-dependent difference in temperature tolerance (Ref. 2, 23). Somewhat aggressive toward other species (Ref. 36683). Marketed fresh and frozen (Ref. 9987). Excellent palatability (Ref. 6465), with small head and large dress-out weight (Ref. 61), and filets without small bones (Ref. 57960). Used extensively in biological, physiological and behavioural research (Ref. 7248). Translocated and introduced for aquaculture, sport fishing, stocking man-made lakes and biological control of nuisance plants and animals (Ref. 6465). Eurytopic; a most successful and vagile invader (Ref. 6465).
    Mozambique tilapia
    provided by wikipedia

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

    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 weak banding may be seen. Adults reach approximately 35 cm (14 in) in length and up to 1.13 kg (2.5 lb). Size and coloration may vary in captive and naturalized populations due to environmental and breeding pressures. It lives 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), but sustained water temperatures of 55°F are lethal to Mozambique tilapia.[citation needed]

    Distribution

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    preserved for lab purposes.

    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.[4] It is threatened in its home range by competition with the invasive Nile tilapia.[5]

    Diet

    Mozambique tilapia are omnivorous. They can consume detrital material, diatoms, invertebrates, small fry and vegetation ranging from macroalgae to rooted plants.[6][7] 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.[8] It has been nominated by the Invasive Species Specialist Group as one of the 100 worst invasive species in the world.[9] It can harm native fish populations through competition for food and nesting space, as well as by directly consuming small fish.[10] 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.[11][12]

    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 a popular commercial hybrid of Mozambique and blue tilapia.[13]

    Feeding behavior and environment

    Although Mozambique tilapias generally live in rivers and lagoons, they can also colonize fast-flowing areas of water such as creeks and streams. Due to their robust nature, Mozambique tilapias often over-colonize the habitat around them, eventually becoming the most abundant species in a particular area. When over-crowding happens and resources get scarce, adults will sometimes cannibalize the young for more nutrients. Mozambique tilapia, like other fish such as Nile tilapia and trout, are opportunistic omnivores and will feed on algae, plant matter, organic particles, small invertebrates and other fish.[14] Feeding patterns vary depending on which food source is the most abundant and the most accessible at the time. In captivity, Mozambique tilapias have been known to learn how to feed themselves using demand feeders. During commercial feeding, the fish may energetically jump out of the water for food.[15]

    Social structure

    Mozambique tilapias often travel in groups where a strict dominance hierarchy is maintained. Positions within the hierarchy correlate with territoriality, courtship rate, nest size, aggression, and hormone production.[16] In terms of social structure, Mozambique tilapias engage in a system known as lek-breeding, where males establish territories with dominance hierarchies while females travel between them. Social hierarchies typically develop because of competition for limited resources including food, territories, or mates. During the breeding season, males cluster around certain territory, forming a dense aggregation in shallow water.[17] This aggregation forms the basis of the lek through which the females preferentially choose their mates. Reproductive success by males within the lek is highly correlated to social status and dominance.[18]

    In experiments with captive tilapias, evidence demonstrates the formation of linear hierarchies where the alpha male participates in significantly more agonistic interactions. Thus, males that are higher ranked initiate much more aggressive acts than subordinate males. However, contrary to popular belief, Mozambique tilapias display more agonistic interactions towards fish that are farther apart in the hierarchy scale than they do towards individuals closer in rank. One hypothesis behind this action rests with the fact that aggressive actions are costly. In this context, members of this social system tend to avoid confrontations with neighboring ranks in order to conserve resources rather than engage in an unclear and risky fight. Instead, dominant individuals seek to bully subordinate tilapias both for an easy fight and to keep their rank.[19]

    Communication and aggression

    Urine in Mozambique tilapias, like many freshwater fish species, acts as a vector for communication amongst individuals. Hormones and pheromones released with urine by the fish often affect the behavior and physiology of the opposite sex. Dominant males signal females through the use of a urinary odorant. Further studies have suggested that females respond to the ratio of chemicals within the urine, as opposed to the odor itself. Nevertheless, females are known to be able to distinguish between hierarchical rank and dominant vs. subordinate males through chemicals in urine.

    Urinary pheromones also play a part in male – male interaction for Mozambique tilapias. Studies have shown that male aggression is highly correlated with increased urination. Symmetrical aggression between males resulted in an increase in the release of urination frequency. Dominant males both store and release more potent urine during agonistic interactions. Thus, both the initial stage of lek formation and the maintenance of social hierarchy may highly depend on the males’ varying urinary output.[20]

    Aggression amongst males usually involve a typical sequence of visual, acoustic, and tactile signals that eventually escalates to physical confrontation if no resolution is reached. Usually, conflict ends before physical aggression as fights are both costly and risky. Bodily damage may impede an individual’s ability to find a mate in the future. In order to prevent cheating, in which individual may fake his own fitness, these aggressive rituals incur significant energetic costs. Thus, cheating is prevented by the sheer 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 winner and the loser.[21]

    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 until the fry hatch; this act is called mouthbrooding.[22] One of the main reasons behind the aggressive actions of Mozambique tilapias is access to reproductive mates. The designation of Mozambique tilapias as an invasive species rests on their life-history traits: Tilapias exhibit high levels of parental care as well as the capacity to spawn multiple broods through an extended reproductive season, both contributing to their success in varying environments.[23] In the lek system, males congregate and display themselves to attract females for matings. Thus, mating success is highly skewed towards dominant males, who tend to be larger, more aggressive, and more effective at defending territories. Dominant males also build larger nests for the spawn.[17] 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 as well as higher pulse rates. At the end of mating, males guard the nest while females take both the eggs and the sperm into their mouth. Due to this, Mozambique tilapias can occupy many niches during spawning since the young can be transported in the mouth.[24] These proficient reproductive strategies may be the cause behind their invasive tendencies.

    Male Mozambique tilapias synchronize breeding behavior in terms of courtship activity and territoriality in order to take advantage of female spawning synchrony. 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 result, 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 floater, travelling between territories in an attempt to find a mate. Nevertheless, it is the dominant males who have the greatest reproductive advantage.[25]

    Parental care

    Typically, Mozambique tilapias, like all species belonging to the Oreochromis genus and species like Astatotilapia burtoni, are maternal mouthbrooders, meaning that spawn is incubated and raised in the mouth of the mother. Parental care is, therefore, almost exclusive to the female. Males do contribute by providing nests for the spawn before incubation, but the energy costs associated with nest production is low relative to mouthbrooding. Compared to nonmouthbrooders, both mouthbrooding and growing a new clutch of eggs is not energetically feasible. Thus, Mozambique tilapias arrest oocyte growth during mouthbrooding to conserve energy.[26] Even with oocyte arrest, 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 offspring carries the cost of reducing her own individual fitness. Unlike most fish, Mozambique tilapias exhibit an extended maternal care period believed to allow social bonds to be formed.[27]

    Use in aquaculture

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    A Mozambique tilapia caught in a man-made lake, where it naturally occurs along with species introduced for aquaculture in Pune, India

    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.[28] Tilapia are very susceptible to diseases such as whirling disease and ich.[22] Mozambique tilapia are resistant to wide varieties of water quality issues and pollution levels. Because of these abilities they have been used as bioassay organisms to generate metal toxicity data for risk assessments of local freshwater species in South Africa rivers.[29]

    Other names

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

    • Mujair in Indonesia
    • Oreochromis andersonii
    • Tilapia kafuensis
    • Kafue bream
    • Three-spotted tilapia
    • Daya in Pakistan

    References

    1. ^ Cambray, J. & Swartz, E. 2007. Oreochromis mossambicus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. www.iucnredlist.org. Downloaded on 10 May 2013.
    2. ^ http://www.parquesnacionales.gov.co/portal/especies-exoticas-con-potencial-invasor/listado-oficial-de-especies-invasoras-para-colombia/
    3. ^ Big Bass
    4. ^ http://www.issg.org/database/species/ecology.asp?si=131
    5. ^ Waal 2002
    6. ^ Mook 1983
    7. ^ Trewevas 1983
    8. ^ Moyle 1976
    9. ^ Courtenay 1989
    10. ^ Courtenay et al. 1974
    11. ^ Courtenay and Robins 1989
    12. ^ Swift et al. 1993
    13. ^ http://edis.ifas.ufl.edu/FA012
    14. ^ "Biology and ecology of Mozambique tilapia (Oreochromis mossambicus)" (PDF). feral.org.au. Retrieved 24 October 2013..mw-parser-output cite.citation{font-style:inherit}.mw-parser-output q{quotes:"""""'"'"}.mw-parser-output code.cs1-code{color:inherit;background:inherit;border:inherit;padding:inherit}.mw-parser-output .cs1-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/6/65/Lock-green.svg/9px-Lock-green.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-limited a,.mw-parser-output .cs1-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/d/d6/Lock-gray-alt-2.svg/9px-Lock-gray-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/thumb/a/aa/Lock-red-alt-2.svg/9px-Lock-red-alt-2.svg.png")no-repeat;background-position:right .1em center}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration{color:#555}.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration span{border-bottom:1px dotted;cursor:help}.mw-parser-output .cs1-hidden-error{display:none;font-size:100%}.mw-parser-output .cs1-visible-error{font-size:100%}.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registration,.mw-parser-output .cs1-format{font-size:95%}.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-right{padding-right:0.2em}
    15. ^ De Peaza, Mia. "Oreochromis mossambicus (Mozambique Tilapia)" (PDF). UWI. Retrieved 24 October 2013.
    16. ^ Oliveira, Rui F.; Vitor C. Almada; Adelino V. M. Canario (1996). "Social Modulation of Sex Steroid Concentrations in the Urine of Male Cichlid Fish Oreochromis mossambicus". Hormones and Behavior. 30: 2–12. doi:10.1006/hbeh.1996.0002. PMID 8724173.
    17. ^ a b Amorim, M. Clara P.; Almada, Vitor C. (1 March 2005). "The outcome of male–male encounters affects subsequent sound production during courtship in the cichlid fish Oreochromis mossambicus". Animal Behaviour. 69 (3): 595–601. doi:10.1016/j.anbehav.2004.06.016.
    18. ^ Barata, Eduardo N.; Fine, Jared M.; Hubbard, Peter C.; Almeida, Olinda G.; Frade, Pedro; Sorensen, Peter W.; Canário, Adelino V. M. (1 April 2008). "A Sterol-Like Odorant in the Urine of Mozambique Tilapia Males Likely Signals Social Dominance to Females". Journal of Chemical Ecology. 34 (4): 438–449. doi:10.1007/s10886-008-9458-7.
    19. ^ Oliveira, R.F.; V.C. Almada (1996). "Dominance hierarchies and social structure in captive groups of the Mozambique tilapia Oreochromis mossambicus (Teleostei Cichlidae)". Ethology Ecology & Evolution. 8: 39–55. doi:10.1080/08927014.1996.9522934.
    20. ^ Barata, Eduardo N; Hubbard, Peter C; Almeida, Olinda G; Miranda, António; Canário, Adelino VM (1 January 2007). "Male urine signals social rank in the Mozambique tilapia (Oreochromis mossambicus)". BMC Biology. 5 (1): 54. doi:10.1186/1741-7007-5-54.
    21. ^ Ros, Albert F.H.; Klaus Becker; Rui F. Oliveira (30 May 2006). "Aggressive behaviour and energy metabolism in a cichlid fish, Oreochromis mossambicus". Physiology & Behavior. 89: 164–70. doi:10.1016/j.physbeh.2006.05.043.
    22. ^ a b Popma, 1999
    23. ^ Russell, D. J.; Thuesen, P. A.; Thomson, F. E. (1 May 2012). "Reproductive strategies of two invasive tilapia species Oreochromis mossambicus and Tilapia mariae in northern Australia". Journal of Fish Biology. 80 (6): 2176–2197. doi:10.1111/j.1095-8649.2012.03267.x.
    24. ^ Amorim, M. C. P.; Fonseca, P. J.; Almada, V. C. (1 March 2003). "Sound production during courtship and spawning of Oreochromis mossambicus: male-female and male-male interactions". Journal of Fish Biology. 62 (3): 658–672. doi:10.1046/j.1095-8649.2003.00054.x.
    25. ^ Oliveira, R. F.; Almada, V. C. (1 June 1998). "Mating tactics and male-male courtship in the lek-breeding cichlid Oreochromis mossambicus". Journal of Fish Biology. 52 (6): 1115–1129. doi:10.1111/j.1095-8649.1998.tb00959.x.
    26. ^ Smith, Carol Johnson; Haley, Samuel R. (1 January 1988). "Steroid profiles of the female tilapia, Oreochromis mossambicus, and correlation with oocyte growth and mouthbrooding behavior". General and Comparative Endocrinology. 69 (1): 88–98. doi:10.1016/0016-6480(88)90056-1.
    27. ^ Russock, Howard I. (March 1986). "Preferential Behaviour of Sarotherodon (Oreochromis) mossambicus (Pisces: Cichlidae) Fry to Maternal Models and Its Relevance to the Concept of Imprinting". Behaviour. 96 (3/4): 304–321. doi:10.1163/156853986x00531.
    28. ^ Gupta and Acosta 2004
    29. ^ Mashifane, TB; Moyo, NAG (29 October 2014). "Acute toxicity of selected heavy metals to Oreochromis mossambicus fry and fingerlings". African Journal of Aquatic Science. 39 (3): 279–285. doi:10.2989/16085914.2014.960358.

Distribution

Morphology

    Morphology
    provided by Fishbase
    Dorsal spines (total): 15 - 18; Dorsal soft rays (total): 10 - 13; Analspines: 3; Analsoft rays: 7 - 12; Vertebrae: 28 - 31

Size

Diagnostic Description

    Description
    provided by World Register of Marine Species
    Occurs at temperatures ranging from 8°-42°C (Ref. 3). Lives in warm, weedy pools of sluggish streams, canals, and ponds (Ref. 5723). Is mainly diurnal. May form schools. Omnivorous, feeds on almost anything from algae to insects. Can be reared under hypersaline conditions (Ref. 4537). Marketed fresh and frozen (Ref. 9987).
    Diagnostic Description
    provided by FAO species catalogs
    Body compressed; caudal peduncle longer than deep.

    Scales cycloid.

    A knob-like protuberance present behind upper jaw on dorsal surface of snout. Upper jaw length shows sexual dimorphism, and mouth of male larger than that of female.

    First gill arch with 20 to 22 gillrakers.

    Lateral line interrupted.

    Spinous and soft ray parts of dorsal fin continuous. Dorsal fin with 15 to 18 spines and 10 to 13 soft rays. Anal fin with 3 spines and 9-10 rays. Caudal fin truncated.

    Colour in spawning season, pectoral, dorsal and caudal fins becoming reddish; colour male shows much brighter orange tail than female.

    Diagnostic Description
    provided by Fishbase
    Diagnosis: snout long; forehead with relatively large scales, starting with 2 scales between the eyes followed by 9 scales up to the dorsal fin (Ref. 3058, 3060). Adult males develop a pointed, duckbill-like snout (Ref. 52307) due to enlarged jaws, often causing the upper profile to become concave (Ref. 2, 7248, 12524, 13337, 52307), but upper profile convex in smaller specimens (Ref. 1870, 6460). Pharyngeal teeth very fine, the dentigerous area with narrow lobes, the blade in adults longer than dentigerous area; 28-31 vertebrae; 3 anal spines; 14-20 lower gill-rakers; genital papilla of males simple or with a shallow distal notch; caudal fin not densely scaled; female and non-breeding male silvery with 2-5 mid-lateral blotches and some of a more dorsal series; breeding male black with white lower parts of head and red margins to dorsal and caudal fins (Ref. 2). Description: moderately deep-bodied (Ref. 7248, 52307), but very variable according to food availability (Ref. 5214). Head profile straight in juveniles and females (Ref. 7248). Mouth large (Ref. 1870, 2989, 53262, 52307, 54167). Lower jaw prominent; lips thick (Ref. 3058, 3060). Maxillary ending between nostril and eye in females and immature males (Ref. 2), in breeding males (Ref. 2) mouth reaching to below anterior border of eye (Ref. 1870, 2989, 53262, 54167, 54759) or a little beyond (Ref. 1870, 2989, 53262, 54167). Eye with yellow ring around pupil (Ref. 57960). Otoliths: sulcus with nearly straight crista inferior at the transition between ostium and cauda (thus no ventralward widening of the ostium is present) (Ref. 56279). 2-3 series of scales on cheek (Ref. 2, 552, 1870, 2989, 3058, 3060, 6460, 53262, 54167). Scales cycloid (Ref. 1870, 2989, 3058, 4904, 5728, 53262, 54167). Scales on belly small, breast scales even smaller (Ref. 3058). Large scales on opercle (Ref. 1870, 53262), in 3 rows (Ref. 54759). 17-23 scales in upper part of lateral line, 10-17 in lower part (Ref. 1870, 2989, 3058, 54167). 9-12 predorsal scales (Ref. 57928). 15 precaudal vertebrae; 15-16 caudal vertebrae; 12-13 pairs of pleural ribs; 2 pairs of epineurals; 6 pairs of epipleurals; ventral vertebral apothysis on third vertebra (Ref. 57928). Gill-rakers short (Ref. 1870, 2989, 5214, 6465, 12524, 13337, 54167) and thick (Ref. 54167). Dorsal fin spines subequal from the sixth; dorsal soft rays a little longer than longest spines (Ref. 54167). Last dorsal spine the longest (Ref. 1870, 54167). Soft part of dorsal and anal fin long and pointed (Ref. 1870, 3058, 3060, 4904, 53262), especially in males (Ref. 44586). Dorsal fin with 25-28 pterygiophores (Ref. 57928). Pectoral fin (nearly) as long as head (Ref. 1870, 2989, 53262, 54167), pointed (Ref. 1870, 6460, 53262, 54759), reaching to vent (Ref. 6460, 54167) or to a little beyond origin of anal fin (Ref. 1870, 2989, 53262, 54167, 54759). 4-6 scales between bases of pectoral and pelvic fins (Ref. 2). Anal fin with 11-12 pterygiophores (Ref. 57928). Outer rays of pelvic fins slightly produced, reaching to vent (Ref. 1870, 54167) or beyond origin of anal (Ref. 1870, 2989). Caudal fin scaly in the basal half (Ref. 1870, 6460, 53262), the angles sometimes rounded (Ref. 2, 54167). Central caudal fin skeleton with 3 epurals, 5 hypurals and 2 pairs of uroneurals (Ref. 57928). No genital tassel (Ref. 55077). Coloration: basic melanin pattern of 2 horizontal and 6-7 vertical bars never fully realized; more commonly, at least in preserved specimens, females and sexually inactive males have no bands, but may have the intersection points of the facultative bands represented by 3-4 upper and 2-5 mid-lateral blotches, or some or all of these may be present (Ref. 2). Basic body coloration silvery grey (Ref. 2, 52307) to greenish grey, sometimes a more bluish colored head (Ref. 52307). Belly greyish (Ref. 4904, 5214, 54167). Spiny part of dorsal fin light with dark mottling (Ref. 3058). Soft dorsal and anal, and caudal and pelvic fins blackish (Ref. 2989, 3058, 3060, 54167). Pectoral fins colorless (Ref. 3058, 3060). Indistinct, dark opercular spot present (Ref. 1870, 2989, 3058, 3060, 53262, 54167, 54759). Vertical fins uniform (Ref. 54167), blackish with more or less distinct whitish spots(Ref. 552) or with large or small, fused or non-fused, dark spots on a pale background (Ref. 6460, 54167), given a darker aspect to these fins (Ref. 6460). 3 black blotches present in juveniles but possibly obscured in adults due to the dark body coloration of breeding males or old adults (Ref. 12524, 13337). Female and non-breeding male: dirty yellowish-olive (Ref. 12522) or silvery-gray, with 2-5 mid-lateral blotches and some of a more dorsal series (Ref. 2, 52307). Sometimes a series of more or less distinct spots along the side of the body above and below the upper lateral line (Ref. 54167). Breeding male: uniform dark olive-brown (Ref. 4904, 54167), deep blue-black (Ref. 2) or black, with white lower parts of head (Ref. 2, 4904, 7248, 54167), including throat, lower lips, lower parts of cheeks and opercles, but with a dark blue to black base to the throat (Ref. 12501, 52307), and red margins to dorsal and caudal fins (Ref. 2, 7248, 12522, 12501, 12524, 13337, 52307). Dorsal fin with light coloured spots on membrane between spinous and soft rays (Ref. 12524, 13337). Caudal fin olive-green with light coloured spots on anterior section (Ref. 12524, 13337), but may sometimes appear totally red (Ref. 52307). Tip of dorsal and extremity of caudal lobes yellowish (Ref. 4904, 54167). Anal fin dark gray (Ref. 52307) or olive-green (Ref. 12524, 13337), sometimes with a thin red/orange margin (Ref. 12501, 12522, 12524, 13337, 52307). Unpaired fins normally exhibit greenish to silvery iridescent dots (Ref. 52307). Pectoral fin rays red (Ref. 2). Pectoral and pelvic fins olive-yellow (Ref. 12524). Juveniles: body silvery (Ref. 2, 5214, 6465, 7248, 12524, 13337, 55020, 57960) or olive-brown, light on belly (Ref. 54167). Scales with dark outer edge (Ref. 54167). Usually 5-8 or more indistinct dark cross bars on body (Ref. 2, 6460, 7248, 39866, 54167, 55020), often in addition to the 2 series of blackish spots (Ref. 54167), but with no horizontal stripes (Ref. 2). Dark opercular spot (Ref. 6460, 54167), on posterior dorsal edge of operculum (Ref. 55020). Black spot at base of anterior rays of soft dorsal (Ref. 552, 54167) and 1-2 whitish spots enclosed by dark streaks (Ref. 54167). Oblique streaks (Ref. 6460) or translucent round spots (Ref. 55020) on soft dorsal. Anal dark at base with a light outer half (Ref. 54167), with oblique streaks (Ref. 6460). Caudal dark at base, light in centre, a black outer ridge (Ref. 54167), with 2-3 bars across the fin (Ref. 6460). Tilapia-spot present (Ref. 2, 5214, 6465, 12501), conspicuous in younger fish persisting albeit faintly to 8cm (Ref. 55020). Fins flesh coloured (Ref. 12524, 13337), all except soft dorsal immaculate (Ref. 55020).

Migration

    Migration
    provided by Fishbase
    Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well-grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there (Ref. 82692).

Trophic Strategy

    Trophic Strategy
    provided by Fishbase
    Inhabits lower Zambezi, Limpopo and eastern rivers southwards. Prefers sheltered banks provided with vegetation. The adult tilapia mainly occupy deeper terraces which surround the lake at high-water levels. Feeds on detritus, plankton, and algae (Ref. 11889). Small fish fed initially on zoobenthos and zooplankton, but fish with a mass of over 4 g fed increasingly on Microcystis aeruginosa and detritus (Ref. 43783). Increased in rainfall improved the quality of diet, as level of protein, energy and organic matter in the diet increased in quantity (Ref. 52847). Utilized in rice fish culture (Ref. 26236).

Diseases and Parasites

    Diseases and Parasites
    provided by Fishbase
    Velvet Disease 2 (Piscinoodinium sp.). Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Ambiphyra Infestation 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Saccocoelioides Infection. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Goezia Disease 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Rhabdochona Infestation 6. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Contracaecum Disease (larvae). Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Gnathostoma Infestation 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Gnathostoma Disease (larvae). Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Spinning Tilapia Syndrome. Viral diseases
    Diseases and Parasites
    provided by Fishbase
    Diplostomum Infection. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Fish Tuberculosis 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Dolops Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    White spot Disease. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Pentastoma Infection 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Fish louse Infestation 1. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Dactylogyrus Gill Flukes Disease. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Cryptobia Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    False Fungal Infection (Epistylis sp.). Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Transversotrema Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Trichodinella Infection 1. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Turbidity of the Skin (Freshwater fish). Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Trichodina Infection 1. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Ichthyobodo Infection. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Trichodina Infection 5. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Amyloodinium Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Orientocreadium Disease. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Cichlidogyrus Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Ichthyophthirius Disease. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Fish Louse Infestation 3. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Cichlidogyrus Infestation 4. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Epitheliocystis. Bacterial diseases
    Diseases and Parasites
    provided by Fishbase
    Trichodinosis. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Lernaea Infestation. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    HTRLO Disease. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Euclinostomum Infestation 2. Parasitic infestations (protozoa, worms, etc.)
    Diseases and Parasites
    provided by Fishbase
    Edwardsiellosis. Bacterial diseases

Life Cycle

    Life Cycle
    provided by Fishbase
    Spawns at the edge of the littoral terrace of lakes (Ref. 1, 2, 87, 6465), in sandy or muddy bottoms (Ref. 57425). Displays a lek mating system; territorial males establish breeding territories where they dig spawning pits, assume a dark coloration, defend a breeding territory and actively court females; sneaking males intrude into nests during a spawning episode, exhibiting quivering behavior which is usually an indicator of sperm release; sneaking is predominantly performed by subordinate males, which may adopt pseudo-female behavior (Ref. 57425). Only territorial males produce sounds, during all phases of courtship but especially during the late stages, including spawning (Ref. 49830). Territorial male excavates and defends a basin-shaped pit in the center of his territory, where female deposits 100-1700(1800) eggs (Ref. 44894, 52307). Eggs and milt are sucked up by the female (Ref. 2, 44894). Fertilization is reported to sometimes occur in the mouth of the female (Ref. 6028). Females incubate eggs alone (Ref. 12501, 52307). It is possible, albeit rare, that males take up some eggs after spawning (Ref. 2, 5726, 52307, 57895), but they almost always eat them soon after (Ref. 52307). Females school together while mouthbrooding (Ref. 40035), they cease to feed and subsist on food reserves stored in their body (Ref. 1). Females may spawn a full clutch with just one male, or may spawn with several different males in a series (Ref. 52307). Water is circulated over the eggs by chewing movements of the jaws (Ref. 12501, 12522). Fry hatch in the female's mouth after 3-5 days (Ref. 2, 12501, 12522, 44894, 52307), depending on the temperature (Ref. 52307). The young are released from the mouth in 10-14 days, but remain near the female and enter the mouth if threatened until about 3 weeks old (Ref. 2, 44894, 52307). Fry and juveniles shoal in shallow water (Ref. 6465, 7248, 57895) where they feed during the day, and retreat to deep water at night (Ref. 87, 6465). Females raise multiple broods during a season (Ref. 7248, 57895).

Threats

    Threats
    provided by Fishbase
    Near Threatened (NT)

Benefits

    Importance
    provided by Fishbase
    fisheries: highly commercial; aquaculture: commercial; gamefish: yes; aquarium: commercial
    Benefits
    provided by FAO species catalogs
    Important food fish in Southeast Asia. Caught with seines, set-nets, traps, and gillnets. The total catch reported for this species to FAO for 1999 was 20 500 t. The countries with the largest catches were Indonesia (18 190 t) and Papua New Guinea (2 310 t). Marketed fresh and frozen.Imported for the purposes of fish culture and now forms wild populations.