IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackDiscula attrita (R.T. Lowe, 1831)

Discula attrita (R.T. Lowe, 1831)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Hygromiidae
NT Near Treatened
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:
Abreu, C. & Teixeira, D.

Facilitators / Compilers/s:


Assessment Rationale:

Seddon (2008) suggested that the status should be Vulnerable B1ab(iii)  based on the fact that recent records are only from three locations in two small regions (3 km x 3 km) on Porto Santo. The habitats are grassland with threats including possible impact from introduced species, Theba pisana and the rodents which predate on landsnails. Other threats include changes of land-use impacting the grassland.  However, given that these populations have been stable for the last 30 years and that the decline of the habitat quality is not impacting significantly the species, this species has been assessed as Near Threatened (NT), almost meeting criteria B.

Geographic Range:

This species is endemic to the Madeiran islands where it is restricted to three locations in two small areas on the island of Porto Santo (Seddon 2008).

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

Population:

There is no recet data on population trends, although this species is abundant in suitable localities (Seddon 2008).

Habitat and Ecology

This species is found on ground, on rocks and amongst low growing grasses and herbs in Porto Santo.

Major Threat(s):

The grassland species has possible threats including impact from introduced species, Theba pisana and the rodents which predate on landsnails, as well as changes of land-use possibly impacting the grassland due to tourist activity.

Conservation Actions

There are no specific conservation actions for this species, although Porto Santo does now have protected areas.