Species

BackLeiostyla cassidula (R.T. Lowe, 1852)

Leiostyla cassidula (R.T. Lowe, 1852)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Lauriidae
CR Critically Endangered
IUCN Red List Status:

Countries of Occurrence:
Portugal - Madeira

Archipelago(s):
Madeira

Assessor/s:
Seddon, M.B.

Reviewer/s:
Cameron, R., Groh, K., Cuttelod, A. & Neubert, E.

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

This species occurs at one site with a restricted area of occupancy of 4 km2. The site is close to a road where declining quality of habitats is inferred and hence it meets the criteria for Critically Endangered (CR) B2ab(iii).

Geographic Range:

This species is endemic to the Madeiran islands, the type locality was from the head of the Ribeira de Sta Luzia. It was recorded in recent surveys at a single site in central Madeira. It was previously recorded by Waldén (1983) from a single site, which is thought to be close to the current site.

Regions:
Portugal - Madeira
Extent of Occurrence (EOO):
(km2)
Area of Occupancy (AOO):
4 (km2)
Elevation Lower Limit:
(m)
Elevation Upper Limit:
(m)
Biogeographic Realms:
Palearctic
Presence:
Extant
Origin:
Endemic Madeira
Seasonality:
Resident

Population:

The species is not considered abundant, and there are very few recent records in recent surveys at the single site known in central Madeira. Therefore it is not possible to establish trends.

Habitat and Ecology

Wollaston (1878) suggests it is in leaf-litter on rock ledges of large crags. However, Coles (pers. comm. 2008) found it on rock ledges in damp areas. Uncertain whether Wollaston (1878) recorded it from shaded crags within laurisilva forest, as past records suggest the known site at that time was wooded.

Major Threat(s):

The site is close to a road where declining quality of habitats is inferred, as the road creates an area with pollution from run-off, and the species lives in damp habitats with leaf-litter, which would be vulnerable to seepage.

 

Conservation Actions

There are no known conservation actions for the species. Further survey work on the central habitats close to the last records, especially in remote ravines to determine if the species is still extant and if it has a wider range.