Sarotherodon linnellii


Taxonomy [top]

Kingdom Phylum Class Order Family

Scientific Name: Sarotherodon linnellii
Species Authority: (Lönnberg, 1903)
Common Name(s):
English Blackbelly Tilapia, Blackfin Tilapia, Unga
Sarotherodon linnelli (Lönnberg, 1903)
Tilapia linnellii Lönnberg, 1903

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(iii)+2ab(iii) ver 3.1
Year Published: 2010
Date Assessed: 2009-02-16
Assessor(s): Moelants, T.
Reviewer(s): Brummett, R., Mbe Tawe, A.N., Dening Touokong, C., Reid, G.M., Snoeks, J. Staissny, M., Moelants, T., Mamonekene, V., Ndodet, B., Ifuta, S.N.B., Chilala, A., Monsembula, R., Ibala Zamba, A., Opoye Itoua, O., Pouomogne, V., Darwall, W. & Smith, K.
The species is endemic to the crater Lake Brombi Mbo (7 km²). The species is currently major threat is from oil plantations and slash and burn agriculture leading to sedimentation and pollution in the lake (1 location). There are plans to commercial development the area for tourism. There is also a potential threat from the lake 'burping' - CO2 (as in Lake Nyos). In addition deforestation of the surroundings of the crater may cause more wind which could lead to the lake 'turning', as the lake is stratified, lower layer being very low in oxygen and high in organic matter. Higher winds may cause currents in the lake which could cause this lower layer to mix with the upper layer where the fish live. This would cause a massive decrease in oxygen in the water and kills the fish. Together with the water abstraction to supply the town of Kumba (which is likely to increase) and the plans to commercial development the area for tourism, this species is considered Critically Endangered.
1996 Critically Endangered
1994 Vulnerable (Groombridge 1994)
1990 Vulnerable (IUCN 1990)
1988 Vulnerable (IUCN Conservation Monitoring Centre 1988)
1986 Vulnerable (IUCN Conservation Monitoring Centre 1986)

Geographic Range [top]

Range Description: A Lower Guinea endemic, only known from Lake Barombi-Mbo, Cameroon.
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: No information available.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: Sarotherodon linnellii occasionally forms schools; is mainly diurnal. Juveniles feed on mayfly larvae and various terrestrial insects among a diet in which animal items formed a high proportion. Adults feed predominantly on phytoplankton (Trewavas 1983). It is a demersal species.
Systems: Freshwater

Threats [top]

Major Threat(s): The species is potentially threatened by crater lake 'burping' - CO2 gasses (pers. comm., Brummet, R.) as in Lake Nyos. There is evidence that the lake released some CO2 in 2007, as many deep water species were found dead on the surface in the middle of the lake, the water was also very turbid (pers. comm., Dening, C.). Deforestation, palm oil plantation and slash and burn agriculture are leading to pollution and sedimentation of the lake. Deforestation of the area surrounding the lake would lead to increased wind and therefore risk of turnover (it is a stratified lake, where the lower part is very low in oxygen and high in organic matter). This would destroy the top stratified layer where the fish live. Water abstraction is also present in the lake to supply the town of Kumba, which is likely to increase. This will also increase the likelihood of the two stratified layers mixing. There are also plans to commercial development the area for tourism. However, there are no introduced species in the lake, and commercial fishing is forbidden in the lake.

Conservation Actions [top]

Conservation Actions: Commercial fishing is forbidden in the lake.

Citation: Moelants, T. 2010. Sarotherodon linnellii. The IUCN Red List of Threatened Species. Version 2014.3. <>. Downloaded on 02 April 2015.
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