Threespot Tilapia (Oreochromis Andersonii) Ecological Risk Screening Summary

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Threespot Tilapia (Oreochromis andersonii) Ecological Risk Screening Summary

U.S. Fish & Wildlife Service, February 2011 Revised, June 2018 Web Version, 12/4/2020

Organism Type: Fish Overall Risk Assessment Category: Uncertain

Photo: Frederick Hermanus Van der Bank. Released to Public Domain by author Available: http://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxon=Oreochromis%20anderso nii. (June 12, 2018).

1 Native Range and Status in the United States Native Range From Canonico et al. (2005):

“[…] O. andersonii is native only to the Kafue and Zambezi basins and not in other areas of Zambia, […]”

Froese and Pauly (2018) list Oreochromis andersonii as native in Angola, Botswana, Mozambique, Namibia, Zambia, and Zimbabwe.

From Froese and Pauly (2018):

“Africa: Ngami basin, Okavango River; Cunene River and Mossamedes, Angola; upper Zambezi, Kafue River; middle Zambezi, Lake Kariba and Cabora Bassa since construction of dams.”

“Known from Mossamedes [Trewavas 1983], and the rivers Cunene [Trewavas 1966, 1983], Quanza and Lebuzi [Fowler 1930]. [Angola]”

“Known from the Okavango Delta [Beadle 1981] in the Boteti River, Thamalakane River, Nxaraga Lagoon, Xakanixa Lagoon, Magwexana Lagoon, perennial swamp rain pools, mainstream channel and Dungu Lagoon [Merron and Bruton 1995], and from Lake Ngami [Castelnau 1861; Thys van den Audenaerde 1963; Beadle 1981]. [Botswana]”

“Occurs in Kunene, Cuvelai [Okeyo 2003], Kwando, Chobe [van der Waal and Skelton 1984; Okeyo 2003], Okavango [van der Waal 1991; Hay 1996; Okeyo 2003], and Upper Zambezi rivers [Okeyo 2003; Thorstad et al. 2003a]. Also in Lake Liambezi and Linyanti swamps (Caprivi) [van der Waal and Skelton 1984, van der Waal 1985]. [Namibia]”

“Reported as native in the Umgeni River [South Africa] [Fowler 1935].”

“Found in Lake Kariba [Losse 1998], Lake Itezhi-tezhi [Kapasa and Cowx 1991], Kafue River system [Jackson 1961; Everett 1974; Kapetsky 1974; Lowe-McConnell 1982; Skelton 1994; Van Steenberge et al. 2014] and the Upper Zambezi [Jackson 1961; Okeyo 2003; Winemiller and Kelso-Winemiller 2003], including the rivers Kalomo and Lusito [Balon and Coche 1974]. [Zmabia]”

“Occurs in the Upper Zambezi [Bell-Cross and Minshull 1988; Pullin 1988; Kenmuir 1989; Feresu-Shonhiwa and Howard 1998], but since the filling of Lake Kariba occasional specimens may have been collected there; considered abundant in the Upper Zambezi [Bell-Cross and Minshull 1988]. [Zimbabwe]”

Status in the United States No records of Oreochromis andersonii in the United States were found. No records of O. andersonii in trade in the United States were found.

The Florida Fish and Wildlife Conservation Commission has listed the tilapia O. andersonii as a prohibited species. Prohibited nonnative species (FFWCC 2016), “are considered to be dangerous to the ecology and/or the health and welfare of the people of Florida. These species are not allowed to be personally possessed or used for commercial activities.”

Possession of any species of tilapia is prohibited without permit in the State of Louisiana (Louisiana State Legislature 2019).

O. andersonii falls within Group I of New Mexico’s Department of Game and Fish Director’s Species Importation List (New Mexico Department of Game and Fish 2010). Group I species “are designated semi-domesticated animals and do not require an importation permit.”

Tilapia species are prohibited to be sold and used as bait or stocked in heated-water reservoirs in the State of Oklahoma (Oklahoma Secretary of State 2019).

All species in the genus Oreochromis are listed as prohibited in Texas (Texas Parks and Wildlife 2020).

A permit is required to import, possess, or sell any species of tilapia in Virginia (Virginia Department of Game and Inland Fisheries 2020).

All species in the genus Oreochromis are considered regulated Type A species in Washington. Regulated Type A species (Washington State Senate 2019) are “nonnative aquatic animal species that pose a low to moderate invasive risk that can be managed based on intended use or geographic scope of introduction, have a beneficial use, and are a priority for department-led or department-approved management of the species' beneficial use and invasive risks.”

Means of Introductions in the United States No records of Oreochromis andersonii in the United States were found.

Remarks From Canonico et al. (2005):

“At a fish farm that is part of the project, they found ponds stocked with a mixture of O. niloticus and a hybrid between the O. niloticus and the indigenous three-spot tilapia (Oreochromis andersonii).”

From Froese and Pauly (2018):

“May also interbreed with O. mossambicus.”

2 Biology and Ecology Taxonomic Hierarchy and Taxonomic Standing According to Eschmeyer et al. (2018), Oreochromis andersonii (Castelnau 1861) is the valid name for this species. Oreochromis andersonii was originally described as Chromys andersonii Castelanu, 1861.

From ITIS (2018):

Kingdom Animalia Subkingdom Bilateria Infrakingdom Deuterostomia Phylum Chordata Subphylum Vertebrata Infraphylum Gnathostomata Superclass Actinopterygii Class Teleostei Superorder Acanthopterygii Order Perciformes Suborder Labroidei Family Cichlidae Genus Oreochromis Species Oreochromis andersonii (Castelanu, 1861)

Size, Weight, and Age Range From Froese and Pauly (2018):

“Maturity: Lm 24.4, range 12 - 15 cm Max length : 61.0 cm TL male/unsexed; [IGFA 2001]; max. published weight: 4.7 kg [IGFA 2001]; max. reported age: 13 years [Booth et al. 1995]” Environment From Froese and Pauly (2018):

“Freshwater; brackish; benthopelagic; depth range 0 - 10 m [Thorstad et al. 2003b], usually 3 - 6 m [Thorstad et al. 2003b]. […]; 18°C - 33°C [water temperature] [Philippart and Ruwet 1982]; […]”

Climate From Froese and Pauly (2018):

“Tropical; […]; 12°S - 21°S”

Distribution Outside the United States Native From Canonico et al. (2005):

“[…] O. andersonii is native only to the Kafue and Zambezi basins and not in other areas of Zambia, […]”

Froese and Pauly (2018) list Oreochromis andersonii as native in Angola, Botswana, Mozambique, Namibia, Zambia, and Zimbabwe.

From Froese and Pauly (2018):

“Africa: Ngami basin, Okavango River; Cunene River and Mossamedes, Angola; upper Zambezi, Kafue River; middle Zambezi, Lake Kariba and Cabora Bassa since construction of dams.”

“Known from Mossamedes [Trewavas 1983], and the rivers Cunene [Trewavas 1966, 1983], Quanza and Lebuzi [Fowler 1930]. [Angola]”

“Reported as native in the Umgeni River [South Africa] [Fowler 1935].”

Introduced Froese and Pauly (2018) list Oreochromis andersonii as introduced in Democratic Republic of the Congo, Kenya, South Africa, and Tanzania.

From Froese and Pauly (2018):

“Reported as introduced in Kasanka National Park (upper Congo River basin) in Zambia [Van Steenberge et al. 2014].”

“Introduced fish collected in main channel of Kasanka River and its associated pools (upper Luapula River, upper Congo River basin) [Zambia]; […]”

“Introduced in the Shashe River (Limpopo tributary) [Botswana] [Kleynhans and Hoffman 1992].”

“Introduced by the Botswana government from the Okavango River (country unknown) to the Shashi Dam in Botswana in 1973, probably for angling purposes [Wohlfarth and Hulata 1983]. Introduction in the region of the confluence of the Orange and Vaal Rivers (South Africa) resulted in the fish dying out probably due to low winter temperatures; a date or area of origin for this last introduction is not given [Wohlfarth and Hulata 1983].”

“Acclimatised to Kipopo River [Democratic Republic of the Congo] [Moreau et al. 1988].”

“Introduced [to Kenya] in 1980 from Botswana by I. Parker for aquaculture purposes [Seegers et al. 2003]. About a thousand juvenile tilapiines, which later proved to be a mixture of Oreochromis andersonii, Oreochromis macrochir and Tilapia rendalli, were introduced in a dam at Nairobi; it is possible some specimens found their way from the dam to the Nairobi River system [Seegers et al. 2003]. It is unknown if it is established in natural waters [Seegers et al. 2003].”

FAO (2018) lists Oreochromis andersonii as established through natural reproduction in Tanzania, the Democratic Republic of the Congo, and South Africa.

Means of Introduction Outside the United States From Froese and Pauly (2018):

“Also introduced for the control of aquatic vegetation [Robins et al. 1991].”

“[…] it was further distributed, probably for sport fishing or as a forage fish for bass [Anonymous 2001].”

“[…]; possibly escaped from a nearby farm to the Mulembo River during the 2002 rainy season [Van Steenberge et al. 2014].”

Short Description From Froese and Pauly (2018):

“Dorsal spines (total): 15 - 18; Dorsal soft rays (total): 11-15; Anal spines: 3; Anal soft rays: 9 - 13; Vertebrae: 30 - 32. Diagnosis: male genital papilla bluntly conical with a narrow flange slightly notched in the middle; jaws enlarged in breeding males, which in this species are normally not less than 30cm TL; scales in lateral line series 31-35, usually 32-33; scales of cheek in 3 full rows; vertebrae 30-32; total number of dorsal rays 28-31. Pectoral fin in adults 34-43% SL [Trewavas 1983], very long [Castelnau 1861]. Depth of body 40.5-50.5% SL; color-pattern of non-breeding fish and female always including 3 or 4 conspicuous mid-lateral blotches and a red margin on dorsal and caudal fins; breeding male with red margins broader and brighter and general dark, iridescent purplish-brown color of head, back and flanks, masking the blotches; no series of vertical spots or vertical stripes on caudal fin; nest a simple circular depression [Trewavas 1983].”

Biology From Froese and Pauly (2018):

“Occurs in both river and swamp habitats and is adapted to fairly fast-flowing rivers [de Moor and Bruton 1988]. Hardy, tolerating fresh and brackish water (up to 20ppt, [Philippart and Ruwet 1982]), preferring slow-flowing or standing water; adults occupy deep open waters, juveniles remain inshore among vegetation [Skelton 1993, 2001]. Prefers fairly deep, quiet water with some weed cover; hippo pools are a favoured retreat [Bell-Cross 1976; Bell-Cross and Minshull 1988]. Forms schools [Trewavas 1983; Bell-Cross 1976; Bell-Cross and Minshull 1988]. Mainly diurnal; a detritivore which feeds on fine particulate matter [Trewavas 1983], including algae [Jackson 1961; Bell-Cross 1976; Bell-Cross and Minshull 1988; Thorstad et al. 2003a], diatoms, detritus [Skelton 1993, 2001; Thorstad et al. 2003a] and zooplankton [Skelton 1993, 2001]. Larger individuals also take insects and other invertebrates [Thorstad et al. 2003a]. Feeding regime is variable, the diet changes according to food availability [de Moor and Bruton 1988]. Female mouthbrooder [Jackson 1961; Bell-Cross 1976; Lowe-McConnell 1982; Bell-Cross and Minshull 1988; de Moor and Bruton 1988]. Fine angling and table species [Bell-Cross 1976; Bell-Cross and Minshull 1988; de Moor and Bruton 1988].”

“Spawning did not occur in ponds at a temperature below 21°C [Trewavas 1983]. Rarely more than one brood in a season [Jackson 1961; Lowe-McConnell 1982], but known to breed at least twice a year under pond conditions [Bell-Cross 1976; Bell-Cross and Minshull 1988] Males excavate saucer-shaped nests [Mortimer 1960; Jackson 1961; Bell-Cross 1976; Bell-Cross and Minshull 1988; de Moor and Bruton 1988; Kenmuir 1989] that can be up to 75cm in diameter and 30cm deep, using mouth and fins [Mortimer 1960; Trewavas 1983; Lamboj 2004], in the center of their territory [Lamboj 2004], on a sandy substrate (any vegetation is uprooted with its mouth) and in water from 1-3m deep, where they display to attract females [Bell-Cross 1976; Bell-Cross and Minshull 1988; Kenmuir 1989]. Up to 40 nests can be found together [de Moor and Bruton 1988]. Females are the primary care-givers [Lamboj 2004], moutbrooding eggs, larvae and fry; multiple broods are raised during the warmer months [Skelton 1993, 2001]. She lays her eggs in the concavity on top of the nest, the male fertilizes the eggs whereupon the female takes the eggs into her mouth where they are incubated; males guard the nest and females against all intruders; parental care is exercised for the first few weeks after the eggs hatch [Bell- Cross 1976; Bell-Cross and Minshull 1988].”

Human Uses From Froese and Pauly (2018):

“Fisheries: commercial; aquaculture: commercial; gamefish: yes”

“Used in hybridisation trials [Mafwenga 1994].”

Diseases Epizootic ulcerative syndrome is on the 2019 list of OIE-reportable diseases (OIE 2019).

From Froese and Pauly (2018):

“Fish tuberculosis (FishMB), Bacterial diseases Fish Tuberculosis 2, Parasitic infestations (protozoa, worms, etc.)”

Poelen et al. (2014) lists Acanthogyrus tilapiae as a parasite of Oreochromis andersonii.

According to Songe et al. (2012), O. andersonii is confirmed to be susceptible to epizootic ulcerative syndrome.

Threat to Humans From Froese and Pauly (2018):

“Potential pest [de Moor and Bruton 1988]”

3 Impacts of Introductions The following information regards potential impacts of introduction of Oreochromis andersonii.

From de Moor and Bruton (1988):

“O. andersonii is a very adaptable species which thrives in permanent swamps and large rivers as well as in newly inundated shallow pools and small streams. This eurytopy probably means that this species would be a successful invader of new habitats which are-within its range of environmental tolerances (Bruton 1986). It is possible that this species could compete with O. mossambicus as their habitat and feeding preferences are similar. The danger of interbreeding with other indigenous cichlids such as O. mossambicus is real and should be avoided as pure genetic stocks of both species should be conserved.”

Oreochromis andersonii is regulated in Florida, Louisiana, Oklahoma, Texas, and Virginia. It is listed as approved for possession without permit in New Mexico.

4 History of Invasiveness Oreochromis andersonii has not been introduced to the United States (although it has regulations in Florida and other states), that has been introduced in Democratic Republic of the Congo, Kenya, South Africa, and Tanzania, assumingly for angling and aquaculture purposes. It has become established in at least of few of those locations. Some information on potential impacts exists but no information was found regarding documented impacts. For these reasons, the History of Invasiveness is “Data Deficient”.

5 Global Distribution

Figure 1. Known global distribution of Oreochromis andersonii. Locations are in Angola, Democratic Republic of the Congo, Namibia, Zambia, Botswana, Zimbabwe, and Mozambique. Map from GBIF Secretariat (2018).

Figure 2. Additional known global distribution of Oreochromis andersonii. Locations are in Angola, Democratic Republic of the Congo, Namibia, Zambia, Botswana, Zimbabwe, and Mozambique. Map from Froese and Pauly (2018).

6 Distribution Within the United States No records of Oreochromis andersonii in the United States were found.

7 Climate Matching Summary of Climate Matching Analysis The climate match for Oreochromis andersonii was high in western Texas and other areas of the southwest. There were areas of medium match surrounding the high match areas as well as in southern Florida. Everywhere else in the contiguous United States had a low match. The Climate 6 score (Sanders et al. 2018; 16 climate variables; Euclidean distance) for the contiguous United States was 0.050, medium (scores between 0.005 and 0.103, exclusive, are classified as medium). The following states had high individual climate scores: Arizona, New Mexico, and Texas.

Figure 3. RAMP (Sanders et al. 2018) source map showing weather stations in southern Africa selected as source locations (red; Angola, Democratic Republic of the Congo, Namibia, Zambia, Botswana, Zimbabwe, Mozambique) and non-source locations (gray) for Oreochromis andersonii climate matching. Source locations from Froese and Pauly (2018) and GBIF Secretariat (2018). Selected source locations are within 100 km of one or more species occurrences, and do not necessarily represent the locations of occurrences themselves.

Figure 4. Map of RAMP (Sanders et al. 2018) climate matches for Oreochromis andersonii in the contiguous United States based on source locations reported by Froese and Pauly (2018) and GBIF Secretariat (2018). Counts of climate match are tabulated on the left. 0/Blue = Lowest match, 10/Red = Highest match.

The High, Medium, and Low Climate match Categories are based on the following table:

Climate 6: Overall (Count of target points with climate scores 6-10)/ Climate Match (Count of all target points) Category 0.000≤X≤0.005 Low 0.005

8 Certainty of Assessment The certainty of assessment is low. Information on the biology and ecology of this species was available with peer-reviewed literature. Records of introductions were found but there was no information on demonstrated impacts of introduction.

9 Risk Assessment Summary of Risk to the Contiguous United States Threespot tilapia (Oreochromis andersonii) is native to major river systems in southern Africa. It can be found in open water and wetland habitats. O. andersonii is used for both commercial and recreational fisheries. It can carry epizootic ulcerative syndrome, an OIE-reportable disease. This species has been introduced outside of its native range within countries where it is native in other areas and in nearby countries, primarily for aquaculture purposes. Some of those introductions resulted in established populations. The history of invasiveness is classified as “Data Deficient.” There was no information on demonstrated impacts of introduction. The climate match was medium with the areas of highest match in the southwest. The certainty of assessment is low and the overall risk assessment category is uncertain.

Assessment Elements  History of Invasiveness (Sec. 4): Data Deficient  Overall Climate Match Category (Sec. 7): Medium  Certainty of Assessment (Sec. 8): Low  Remarks/Important additional information: Susceptible to epizootic ulcerative syndrome, an OIE-reportable disease  Overall Risk Assessment Category: Uncertain

10 Literature Cited Note: The following references were accessed for this ERSS. References cited within quoted text but not accessed are included below in Section 11.

Canonico GC, Arthington A, McCrary JK, Thieme ML. 2005. The effects of introduced tilapias on native biodiversity. Aquatic Conservation: Marine and Freshwater Ecosystems 15:463–483. de Moor IJ, Bruton MN. 1988. Atlas of alien and translocated indigenous aquatic animals in southern Africa. Pretoria, South Africa: Council for Scientific and Industrial Research, South African National Scientific Programmes 144.

Eschmeyer WN, Fricke R, van der Laan R, editors. 2018. Catalog of fishes: genera, species, references. California Academy of Science. Available: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp (June 2018).

[FAO] Fisheries and Agriculture Organization of the United Nations. 2018. Database on introductions of aquatic species. Rome: FAO. Available: http://www.fao.org/fishery/introsp/search/en (June 2018).

[FFWCC] Florida Fish and Wildlife Conservation Commission. 2016. Prohibited species list. Tallahassee, Florida: Florida Fish and Wildlife Conservation Commission. Available: http://myfwc.com/wildlifehabitats/nonnatives/regulations/prohibited/ (June 2018).

Froese R, Pauly D, editors. 2018. Oreochromis andersonii (Castelnau, 1861). FishBase. Available: https://www.fishbase.de/summary/Oreochromis-andersonii.html (June 2018).

GBIF Secretariat. 2018. GBIF backbone taxonomy: Oreochromis andersonii (Castelnau, 1861). Copenhagen: Global Biodiversity Information Facility. Available: https://www.gbif.org/species/2372323 (June 2018).

[ITIS] Integrated Taxonomic Information System. 2018. Oreochromis andersonii (Castelnau, 1861). Reston, Virginia: Integrated Taxonomic Information System. Available: https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=648 837 (June 2018).

Louisiana State Legislature. 2019. Exotic fish; importation, sale, and possession of certain exotic species prohibited; permit required; penalty. Louisiana Revised Statutes, Title 56, Section 319.

New Mexico Department of Game and Fish. 2010. Director’s species importation list. Santa Fe, New Mexico: New Mexico Department of Game and Fish. Available: http://www.wildlife.state.nm.us/download/enforcement/importation/information/Director s-Species-Importation-List-08_03_2010.pdf (November 2020).

[OIE] World Organisation for Animal Health. 2019. OIE-listed diseases, infections and infestations in force in 2019. Available: http://www.oie.int/animal-health-in-the- world/oie-listed-diseases-2019/ (June 2019).

Oklahoma Secretary of State. 2019. List of restricted exotic species. Oklahoma Administrative Code, Title 800, Chapter 20-1-2.

Poelen JH, Simons JD, Mungall CJ. 2014. Global Biotic Interactions: an open infrastructure to share and analyze species-interaction datasets. Ecological Informatics 24:148–159.

Sanders S, Castiglione C, Hoff M. 2018. Risk Assessment Mapping Program: RAMP. Version 3.1. U.S. Fish and Wildlife Service.

Songe MM, Hang’ombe MB, Phiri H, Mwase M, Choongo K, van der Wall B, Kanchanakhan S, Reanaso MB, Subasinghe RP. 2012. Field observations of fish species susceptible to epizootic ulcerative syndrome in the Zambezi River basin in Sesheke District of Zambia. Tropical Animal Health Proceedings 44:179–183.

Texas Parks and Wildlife. 2020. Invasive, prohibited and exotic species. Austin, Texas: Texas Parks and Wildlife. Available: https://tpwd.texas.gov/huntwild/wild/species/exotic/prohibited_aquatic.phtml (November 2020).

Virginia Department of Game and Inland Fisheries. 2020. Nongame fish, reptile, amphibian and aquatic invertebrate regulations. Henrico, Virginia: Virginia Department of Game and Inland Fisheries. Available: https://www.dgif.virginia.gov/fishing/regulations/nongame/ (November 2020).

Washington State Senate. 2019. Invasive/nonnative species. Washington Administrative Code, Chapter 220-640.

11 Literature Cited in Quoted Material Note: The following references are cited within quoted text within this ERSS, but were not accessed for its preparation. They are included here to provide the reader with more information.

Anonymous. 2001. The co-management of fresh water resources in the Okavango/Zambezi river systems. Proceedings of a Consultative Workshop, Katima Mulilo, Caprivi Region, Republic of Namibia, 2000.

Balon EK, Coche AG. 1974. Lake Kariba: a man-made tropical ecosystem in Central Africa. The Hague, Monograms Biology 24.

Beadle LC. 1981. The inland waters of tropical Africa. An introduction to tropical limnology, 2nd edition. London: Longman Group.

Bell-Cross G. 1976. The fishes of Rhodesia. Salisbury, Rhodesia: National Museums and Monuments of Rhodesia.

Bell-Cross G, Minshull JL. 1988. The fishes of Zimbabwe. Harare, Zimbabwe: National Museums and Monuments of Zimbabwe.

Booth AJ, Merron GS, Buxton CD. 1995. The growth of Oreochromis andersonii (Pisces: Cichlidae) from the Okavango Delta, Botswana, and a comparison of the scale and otolith method of ageing. Environmental Biology of Fishes 43:171–178.

Bruton MN. 1986. Life history styles of invasive fishes in southern Africa. Pages 201–208 in Macdonald IAW, Kruger FJ, Ferrar AA, editors. The ecology and management of biological invasions in southern Africa. Cape Town, South Africa: Oxford University Press.

Castelnau F (de). 1861. Mémoire sur les poissons de l'Afrique australe. Paris: J.-B. Baillière et fils.

Everett GV. 1974. An analysis of the 1970 commercial catch in three areas of the Kafue floodplain. African Journal of Tropical Hydrobiology and Fisheries 3:147–159.

Feresu-Shonhiwa F, Howard JH. 1998. Electrophoretic identification and phylogenetic relationships of indigenous tilapiine species of Zimbabwe. Journal of Fish Biology 53:1178–1206.

Fowler HW. 1930. The fresh-water fishes obtained by the Gray African Expedition 1929. With notes on other species in the Academy collection. Proceedings of the Academy of Natural Science Philadelphia 82:27–83.

Fowler HW. 1935. South African fishes received from Mr. H. W. Bell-Marley in 1935. Proceedings of the Academy of Natural Science Philadelphia 87:361–408.

Hay CJ, van Zyl BJ, Steyn GJ. 1996. A quantitative assessment of the biotic integrity of the Okavango River, Namibia, based on fish. Water SA 22(3):263–284.

IGFA. 2001. Database of IGFA angling records until 2001. Fort Lauderdale, Florida: IGFA.

Jackson PBN. 1961. The fishes of Northern Rhodesia. A check list of indigenous species. Lusaka, Zambia: The Government Printer.

Kapasa CK, Cowx IG. 1991. Post-impoundment changes in the fish fauna of Lake Itezhi-tezhi, Zambia. Journal of Fish Biology 39:783–793.

Kapetsky JM. 1974. The Kafue River floodplain: an example of pre-impoundment potential for fish production. Pages 497–523 in Balon EK, Coche AG, editors. Lake Kariba: a man- made tropical ecosystem in Central Africa. The Hague, Monographs in Biology 24.

Kenmuir, DHS. 1989. Fishes of Kariba. Harare, Zimbabwe: Longman Zimbabwe.

Kleynhans CJ, Hoffman A. 1992. First record of Oreochromis macrochir (Boulenger, 1912) (Pisces: Cichlidae) from the Limpopo River in southern Africa. Southern African Journal of Aquatic Sciences 18(1-2):104–107.

Lamboj A. 2004. The cichlid fishes of Western Africa. Bornheim, Germany: Birgit Schmettkamp Verlag.

Losse GF. 1998. Lake Kariba and the Gwembe Valley. Pages 22–31 in Losse GF. The small- scale fishery on Lake Kariba in Zambia. Eschborn, Germany: Deutsche Gessellscahft für Technische Zusammenarbeit (GTZ) GmbH.

Lowe-McConnell RH. 1982. Tilapias in fish communities. Pages 83–113 in Pullin RSV, Lowe- McConnell RH, editors. The biology and culture of tilapias. ICLARM Conference Proceedings 7.

Mafwenga GAL. 1994. Aquaculture development and research in Tanzania. CIFA Technical Paper 23(supplement):313–349.

Merron GS, Bruton MN. 1995. Community ecology and conservation of the fishes of the Okavango Delta, Botswana. Environmental Biology of Fishes 43:109–119.

Moreau J, Arrignon J, Jubb RA. 1988. Les introductions d'espèces étrangères dans les eaux continentales africaines. Intérêt et limites. Pages 395–425 in Lévêque C, Bruton MN, Ssentongo GW, editors. Biologie et écologie des poissons d'eau douce africains. Éditions se l'ORSTOM, Coll. Trav. et Doc. 216.

Mortimer MAE. 1960. Observations on the biology of Tilapia andersonii (Castelnau), (Pisces, Cichlidae) in Northern Rhodesia. Joint Fisheries Research Organization, Annual Report 9(1959):42–67.

Okeyo DO. 2003. On the biodiversity and the distribution of freshwater fish of Namibia: an annotated update. Pages 156–194 in Palomares MLD, Samb B, Diouf T, Vakily JM, Pauly D, editors. Fish biodiversity: local studies as basis for global inferences. ACP-EU Fisheries Research Report 14.

Philippart JC, Ruwet JC. 1982. Ecology and distribution of tilapias. Pages 15–60 in Pullin RSV, Lowe-McConnell RH, editors. The biology and culture of tilapias. ICLARM Conference Proceedings 7.

Pullin RSV, editors. 1988. Tilapia genetic resources for aquaculture. ICLARM Conference Proceedings 16.

Robins CR, Bailey RM, Bond CE, Brooker JR, Lachner EA, Lea RN, Scott WB. 1991. World fishes important to North Americans. Exclusive of species from the continental waters of the United States and Canada. Bethesda, Maryland: American Fisheries Society. Special Publication 21.

Seegers L, De Vos L, Okeyo DO. 2003. Annotated checklist of the freshwater fishes of Kenya (excluding the lacustrine haplochromines from Lake Victoria). Journal of East African Natural History 92:11–47.

Skelton PH. 1993. A complete guide to the freshwater fishes of southern Africa. Southern Book Publishers. [Source material did not give full citation for this reference.]

Skelton PH. 1994. Diversity and distribution of freshwater fishes in East and Southern Africa. Pages 95–131 in Teugels GG, Guégan JF, Albaret JJ, editors. Biological diversity of African fresh-and brackish water fishes. Geographical overviews presented at the PARADI Symposium, Senegal, 1993. Annales du Musée Royal de l'Afrique Centrale: Sciences Zoologiques 275.

Skelton PH. 2001. A complete guide to the freshwater fishes of southern Africa. Cape Town, South Africa: Struik Publishers.

Thorstad EB, Hay CJ, Næsje TF, Chanda B, Økland F. 2003a. Space use and habitat utilisation of tigerfish and two cichlid species nembwe and threespot tilapia in the Upper Zambezi River. Implications for fisheries management. NINA Project Report 24.

Thorstad EB, Hay CJ, Næsje TF, Chanda B, Økland F. 2003b. Movements and habitat utilisation of threespot tilapia in the Upper Zambezi River. Implications for fisheries management. NINA Project Report 23.

Thys van den Audenaerde DFE. 1963. La distribution géographique des Tilapia au Congo. Bulletin des Séances. Académie Royale des Sciences d'Outre-Mer 9:570–605.

Trewavas E. 1966. A preliminary review of fishes of the genus Tilapia in the eastward-flowing rivers of Africa, with proposals of two new specific names. Revue de Zoologie et de Botanique Africaines 74(3-4):394–424.

Trewavas E. 1983. Tilapiine fishes of the genera Sarotherodon, Oreochromis and Danakilia. London: British Museum of Natural History. van der Waal BCW.1985. Aspects of the biology of larger fish species in Lake Liambezi, Caprivi, South West Africa. Madoqua 14:101–144. van der Waal BCW. 1991. Fish life of the oshana delta in Owambo, Namibia, and the translocation of Cunene species. Madoqua 17:201–209. van der Waal BCW, Skelton PH. 1984. Check list of fishes of Caprivi. Madoqua 13:303–320.

Van Steenberge M, Vreven E, Snoeks J. 2014. The fishes of the Upper Luapula area (Congo basin): a fauna of mixed origin. Ichthyological Explorations of Freshwaters 24:329–345.

Winemiller KO, Kelso-Winemiller LC. 2003. Food habits of tilapiine cichlids of the Upper Zambezi River and floodplain during the descending phase of the hydrologic cycle. Journal of Fish Biology 63:120–128.

Wohlfarth GW, Hulata G. 1983. Applied genetics of tilapias. ICLARM Student Review 6, 2nd edition.