Trochulus caelatus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Stylommatophora Hygromiidae

Scientific Name: Trochulus caelatus
Species Authority: (S. Studer, 1820)
Trichia caelata S. Studer, 1820
Trochulus caelata (S. Studer, 1820)

Assessment Information [top]

Red List Category & Criteria: Near Threatened ver 3.1
Year Published: 2013
Date Assessed: 2010-10-01
Assessor(s): Rüetschi, J.
Reviewer(s): Neubert, E., Bilz, M. & Ward, J.
The species has a very restricted distribution with an extent of occurrence of less than 5,000 km2. The populations are not severely fragmented, occur at several localities and have a presumably stable trend at the moment. However, the habitat is known to be declining and degrading in places as a result of rock climbers and quarrying which takes place in the area, as well as a motorway being built. It is not quite clear how these threats will affect the species and it is therefore classed as Near Threatened (NT). If further population research is carried out the species might also approach Criterion C2(a i) as the number of mature individuals is suspected to be less than 10,000 and the populations are all very small. However, there is not enough evidence to assess the species under this Criterion at present.
Previously published Red List assessments:
1996 Data Deficient (DD)
1994 Rare (R)

Geographic Range [top]

Range Description: This species is endemic to an area South of Basel in the Jura mountains in north-western Switzerland. The extent of occurrence is less than 5,000 km2. The 29 known sites are small and are from between 400 and 1,280 m in altitude.
Countries occurrence:
Lower elevation limit (metres): 400
Upper elevation limit (metres): 1280
Range Map: Click here to open the map viewer and explore range.

Population [top]


 The density is low but the population is thought to be stable at present.

Current Population Trend: Stable
Additional data:
Population severely fragmented: No

Habitat and Ecology [top]

Habitat and Ecology: This species lives in cool, moist gorges on steep carbonate rocks. Few populations have been found on open rocks exposed to sunshine.
Systems: Terrestrial

Threats [top]

Major Threat(s): Quarrying is taking place in the area and rock climbing is another potential threat. There is also a new motorway being built from Biel to Basel with potential implications.

Conservation Actions [top]

Conservation Actions: The species is listed on the Swiss Red List as Vulnerable (VU) (Turner et al. 1998).

The impact of the habitat threats on the species need to be studied and the size of populations needs to be verified if possible.

Citation: Rüetschi, J. 2013. Trochulus caelatus. The IUCN Red List of Threatened Species 2013: e.T22108A9360490. . Downloaded on 02 December 2015.
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