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Tomichia cawstoni

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA MOLLUSCA GASTROPODA LITTORINIMORPHA POMATIOPSIDAE

Scientific Name: Tomichia cawstoni
Species Authority: Connolly, 1939
Synonym/s:
Tomicha cawstoni Connolly, 1939

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(iii)+2ab(iii) ver 3.1
Year Published: 2010
Assessor/s: Kristensen, T.K., Stensgaard, A-S. & Appleton, C.
Reviewer/s: Curtis, B. & Smith, K.
Contributor/s:
Justification:
This species is currently only known from one location, a stream near the Eastern Cape Province, South Africa (M. Bursey and D. Herbet, pers. comm.). It was originally known from the original specimens collected near Kokstad also in the Eastern Cape province (last seen before 1939). Davis and Brown have surveyed the area and not found the species, one area of suitable habitat was found to be polluted with oil and the surrounding fields were heavily grazed by cattle which had trampled the habitat (Davis 1981). Based on this information the species qualifies for Critically Endangered. However, the habitat of the stream the species is currently known from is very different from those visited by Davis (1981) and may indicate a wider distribution for the species than is currently known.
History:
2007 – Critically Endangered
2000 – Critically Endangered
1996 – Extinct

Geographic Range [top]

Range Description: This species is known from the original specimens collected near Kokstad in eastern Cape province (South Africa) (last seen in this area before 1939). Davis and Brown have surveyed the area and not found the species; one area of suitable habitat was found to be polluted with oil and the surrounding fields were heavily grazed and the habitat had been trampled (Davis 1981). It was collected again in 1999 in a stream near the coast of eastern Cape province (M. Bursey and D. Herbet, pers. comm.). This habitat is very different from those visited by Davis (1981) and may indicate a wider distribution for the species than is currently known.
Countries:
Native:
South Africa (Eastern Cape Province)
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: It is found in saline, brackish and freshwaters.
Systems: Freshwater

Threats [top]

Major Threat(s): Oil pollution and trampling of suitable habitat by cattle threaten this species. Species of genus Tomichia are extremely sensitive to changes in their ecosystems relative to pollution of all types as well as interferences in the natural dry-wet seasonal cycles.

Conservation Actions [top]

Conservation Actions: No conservation measures known of.

Bibliography [top]

Brown, D.S. 1994. Freshwater Snails of Africa and their Medical Importance. Taylor & Francis, London.

Brown, D.S. and Kristensen, T.K. 1989. A field guide to African freshwater snails.

Davis, G.M. 1981. Different Modes of Evolution and Adaptive Radiation in the Pomatiopsidae. Malacologia 21(1-2): 209-262.

IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.3). Available at: http://www.iucnredlist.org. (Accessed: 2 September 2010).
Citation: Kristensen, T.K., Stensgaard, A-S. & Appleton, C. 2010. Tomichia cawstoni. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>. Downloaded on 19 May 2013.
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