Discus guerinianus

– Endangered

Taxonomy

Kingdom:	ANIMALIA
Phylum:	MOLLUSCA
Class:	GASTROPODA
Order:	STYLOMMATOPHORA
Family:	DISCIDAE
Scientific Name:	Discus guerinianus
Species Authority:	Lowe, 1852
Common Name/s:	MADEIRAN LAND SNAIL (Eng)

Assessment Information

Red List Category & Criteria:

EN B1+B2c ver 2.3 (1994)

Year Assessed:

2000

Assessor/s:

Seddon, M.B.

Evaluator/s:

Seddon, M.B. (Mollusc Red List Authority)

Justification:

This species was originally listed as possibly extinct by Wells and Chatfield (1992) and Groombridge (1994). It was reassessed as Extinct in the 1996 list (Baillie and Groombridge 1996) as the species has not been recorded since the 1860s despite intensive searching since 1983. Cameron and Cook (1999) rediscovered the species at the west end of the island at two close, but separate locations, in drier but well vegetated regions, which were relatively undisturbed, but differed from the habitats described in Wollaston (1878). Only fresh shells have been recorded to date, but these are sufficiently fresh to assume the species is living at these sites.

History:

1983	-	Vulnerable (Wells et al. 1983)
1986	-	Vulnerable (IUCN Conservation Monitoring Centre 1986)
1988	-	Vulnerable (IUCN Conservation Monitoring Centre 1988)
1990	-	Vulnerable (IUCN 1990)
1994	-	Extinct? (Groombridge 1994)
1996	-	Extinct (Baillie and Groombridge 1996)
1999	-	Critically Endangered (Hilton-Taylor 2000)

Geographic Range

Range Description:	Discus guerinianus is endemic to the Madeiran Islands.
Countries:	Native: Portugal (Madeira)

Population

Population:	After 80 years of being regarded as extinct, the species was rediscovered in a different area of the island.
Population Trend:

Habitat and Ecology

Habitat and Ecology:	In 1878, Wollaston described the habitat as intermediate to high elevations, confined to deep wooded ravines under stones and leaf litter. No other published data is known. Since the species has only recently been rediscovered, there is no available specific information on habitat preferences.
System:	Terrestrial

Citation:	Seddon, M.B. 2000. Discus guerinianus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 04 July 2008.
Disclaimer:	To make use of this information, please check the Copyright and Data Disclaimer.
Feedback:	If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided.