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Etheria elliptica 

Scope: Global
Language: English
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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Bivalvia Unionoida Etheriidae

Scientific Name: Etheria elliptica Lamarck, 1807
Regional Assessments:
Synonym(s):
Etheria semilunata Lamarck, 1807
Etheria transversa Lamarck, 1807
Etheria trigonula Lamarck, 1807
Taxonomic Source(s): Graf, D.L. and Cummings, K.S. 2015. The Freshwater Mussels (Unionoida) of the World (and other less consequential bivalves), updated 5 August 2015. The MUSSEL Project Web Site: MUSSELp. Available at: http://mussel-project.uwsp.edu/index.html.
Taxonomic Notes: Etheria ellipica populations in Africa can be split into two groups with divergent MT DNA (D. Graf pers. comm). The synonyms here listed only pertain to Madagascar material.

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2017
Date Assessed: 2016-06-15
Assessor(s): Van Damme, D. & Seddon, M.B.
Reviewer(s): Sayer, C.
Contributor(s): Graf, D.
Facilitator/Compiler(s): Soulsby, A.-M., Whitton, F., Dyer, E., Kasthala, G., McGuinness, S., De Silva, R., Milligan, H.T., Herdson, R., Thorley, J., Collins, A. & McMillan, K.
Justification:
Etheria elliptica has been assessed as Least Concern as it is widespread throughout continental Africa with no major threats affecting its global population. On Madagascar it appears to have become extinct possibly as early as the beginning of the 20th century. Siltation and increased turbidity due to logging and agriculture are probably the main causes for extinction.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is widely distributed throughout the African continent, from the Nile in Northeast Africa, through the Chad-Chari system to West Africa, and south through the entire Congo Basin to Angola and Zambia. It was formerly also present in northern Madagascar.

Central Africa: It occurs throughout the Congo. Recent research on the distribution in the Congo suggests Cryptic species have been identified, with three distinct clades within the catchment area.

Eastern Africa: It is known from Lakes Victoria, Edward and Tanganyika. In Lake Victoria, Mwanbungu (2004) did not record the species in their dredging surveys in the Tanzanian waters of Lake Victoria, presumably a result of sampling methodology. Graf and Cummings (Mussel-P 2016) found museum specimens from Kisuma in Kenya (Coll. 1984 by Kat, ANSP), Entebbe in Uganda (collection data) and Jinja in Uganda (collection data).

Northern Africa:
In the Nile Basin it was historically reported from the Great Lakes to the Delta. Now it is rare in the Nile, with just one known site where it is possibly already extinct in lower Egypt (Ibrahim et al. 1999).

Northeastern Africa:
It is reported from Sudan, South Sudan, Ethiopia and Somalia.

Southern Africa:
It is found in the Kunene River (recorded from Otjinungua, Ondorusu Falls and at the confluence with Chabicua), the Cuanza River (recorded from Lucala river and Rio Lui) and the Cassai (Cuango) River in Angola.

Western Africa:
This species is not found in northwest Africa. Inhabited rivers include Senegal, Gambia, Mao, Abitifi, Sacbayere, Sewa and Lake Chad (Leveque 1967).

Madagascar: 
It was also present in two western and one northern region on Madagascar, namely from the Mahavavy, Sahondra and Betsiaka basins (Graf and Cummings 2009), but is now likely to be extinct since it has not been recorded live there since the early 20th century. It has never been cited from any of the islands in the Indian Ocean.
Countries occurrence:
Native:
Angola (Angola); Benin; Burkina Faso; Burundi; Cameroon; Central African Republic; Chad; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Equatorial Guinea (Annobón, Bioko, Equatorial Guinea (mainland)); Ethiopia; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Kenya; Liberia; Mali; Mauritania; Niger; Nigeria; Senegal; Sierra Leone; Somalia; South Sudan; Sudan; Tanzania, United Republic of; Togo; Uganda; Zambia
Possibly extinct:
Egypt (Egypt (African part))
Regionally extinct:
Madagascar
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This species is locally abundant throughout its range on the African continent (Yonge 1962). In regions with increasing erosion and pollution the species is decreasing (D. Van Damme pers. comm. 2016). The species is presently extinct from Madagascar and close to extinction in Egypt.
Current Population Trend:Decreasing
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:This species is found in freshwaters with a preference for fast flowing rivers, oxygen-rich borders of large lakes, rapids and waterfalls and attaching to hard substrates such as other oyster shells (forming oyster banks) or rocks (Yonge 1962).
Systems:Freshwater

Use and Trade [top]

Use and Trade: This species is harvested by local people, but no scientific records have been maintained, therefore effects of harvesting are unclear (David 2010). Historically, the shells have been utilised to make lime for cementing and white washing (Pilsbry and Bequaert 1927).

Threats [top]

Major Threat(s): Although there are no specific threats documented for this species, sedimentation as a result of logging, mining and dam building, and pollution are grave issues concerning the freshwater systems of Africa (Graf and Cummings 2009). The species is harvested although it is unclear to what extent.

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation measures in place for this species. Insufficient data exist on population status and trends, in particular in the main river systems of Africa, so that further research is recommended.

Amended [top]

Amended reason: Point locality records for this species were recently compiled by D. Van Damme. As a result of these records, there has been a slight extension to the previously published distribution range for this species. These point locality records are also now displayed on the distribution map.

Citation: Van Damme, D. & Seddon, M.B. 2017. Etheria elliptica. (amended version published in 2016) The IUCN Red List of Threatened Species 2017: e.T165311A110761805. . Downloaded on 18 November 2017.
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