Oreochromis placidus ssp. rovumae
| Kingdom |
Phylum |
Class |
Order |
Family |
| ANIMALIA |
CHORDATA |
ACTINOPTERYGII |
PERCIFORMES |
CICHLIDAE |
| Scientific Name: |
Oreochromis placidus ssp. rovumae |
| Infra-specific Authority: |
(Trewavas, 1966) |
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Common Name/s:
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| Taxonomic Notes: |
From Bills 2004: (36. Oreochromis rovumae (Trewavas 1966), Rovuma tilapia, likwale.
All specimens of Oreochromis collected appear the same and are characterised by relatively small adult size (largest specimen collected 108 mm SL), a series of 3 to 4 spots on the flanks, often with a series of vertical bars on the flanks (up to nine), four anal fin spines. The species appears to be the only Oreochromis in the system also noted by Trewavas (1966). The features agree with the description of O. rovumae Trewavas 1966 although there is overlap with O. shiranus chilwae Trewavas 1966 (Lake Chiuta) and O. placidus Trewavas 1941 (lower Zambezi, Pungwe and Buzi). Oreochromis rovumae was synonomised with O. placidus by Trewavas and Teugels (1991), however, I have observed O. placidus from the type locality and the Rovuma fishes appear distinct, attaining a smaller adult size, being shallower bodied and having a slightly different adult male colour pattern. Oreochromis rovumae are widespread and common in the Niassa Reserve (19 sites, 192 specimens), they are of commercial importance in the fishery and are a dominant species in the trap fishery. Together with the next species they are the most likely candidates for aquaculture developments). |
Assessment Information
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| Red List Category & Criteria: |
Least Concern
ver 3.1
|
| Year Published: |
2007 |
| Assessor/s: |
Bills, R., Engelbrecht, J., Cambray, J. & Marshall, B.E. |
| Reviewer/s: |
Snoeks, J. (Freshwater Fish Red List Authority) & Darwall, W. (Freshwater Biodiversity Assessment Unit) |
Justification:
Widespread and common in suitable habitats of large rivers of the Mozambique coastal plain. Extends into Zimbabwe in the Save River system and the lower Shire in Malawi. No major threats known.
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Geographic Range
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| Range Description: |
Coastal plain rivers of the east African coast from the Mkuze River in KwaZulu-Natal to Lindi, southern Tanzania. In Zimbabwe it occurs in the lower Save-Runde system and lower sections of some Zambezian tributaries e.g., the Mazowe (Bell-Cross and Minshull 1988).
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| Countries: |
Native:
Malawi; Mozambique; South Africa; Tanzania, United Republic of
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| Range Map: |
Click here to open the map viewer and explore range.
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Population
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| Population Trend: |
Unknown
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Habitat and Ecology
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| Habitat and Ecology: |
In the lower Zambezi it was collected in slow flowing sections of main channel habitats and not marginal lagoons. Has been reported only from freshwaters and low altitudes and so its salinity tolerances are probably narrower than O. mossambicus.
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| Systems: |
Freshwater |
| Major Threat(s): |
The spread of O. niloticus is a potential threat although interbreeding between the two species has not yet been reported.
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Conservation Actions
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| Conservation Actions: |
Possibly maintenance of pure stocks in refuge areas. Control of the spread of O. niloticus.
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Bibliography
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Bell-Cross, G. and Minshull, J.L. 1988. The fishes of Zimbabwe. National Museums and Monuments of Zimbabwe, Harare, Zimbabwe.
Bills, I.R. 1999. An inventory of fishes from the lower Zambezi River, Mozambique (27/7/1999 to 14/8/1999). J.L.B. Smith Institute of Ichthyology, Investigational report. J.L.B. Smith Institute of Ichthyology, Grahamstown.
IUCN. 2007. 2007 IUCN Red List of Threatened Species. Available at: www.iucnredlist.org. (Accessed: 12th September 2007).
Skelton, P.H. 2001. A Complete Guide to the Freshwater Fishes of Southern Africa. Struik Publishers, Cape Town, South Africa.
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