IUCN SSC Mid-Atlantic Island Invertebrates Specialist Group

Species

BackTheba impugnata (Mousson, 1857)

Theba impugnata (Mousson, 1857)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Helicidae
VU Vulnerable
IUCN Red List Status:

Countries of Occurrence:
Spain - Canaries

Archipelago(s):
Canaries

Assessor/s:
Groh, K. & Neubert, E.

Reviewer/s:
Neubert, E., Cuttelod, A. & Bilz, M.

Contributor/s:

Facilitators / Compilers/s:


Assessment Rationale:

There are only a few locations known for this species in the north-west of the Island of Lanzarote. There are some threats to this species, and very obviously, living specimens are rare. It thus can be concluded that the population size is small, and non-regulated recreation activities may impact this susceptible species seriously. Therefore, it is assessed as Vulnerable (VU) B1ab(iii).

Geographic Range:

This species is endemic to Lanzarote on the Canary Islands. The species is restricted to the northeastern part of Lanzarote and the adjacent islet of Graciosa. Specimens have been observed at Isla Graciosa and in Lanzarote: El Risco, Orzola, Malpais de la Corona, Cueva de los Verdes, Jameos de Agua, Haría los Valles, Teneguime, Playa de Famara, Montana Corona, Montana de las Nuevas (Gittenberger and Ripken 1987).

Regions:
Spain - Canaries
Extent of Occurrence (EOO):
(km2)
Area of Occupancy (AOO):
(km2)
Elevation Lower Limit:
(m)
Elevation Upper Limit:
(m)
Biogeographic Realms:
Paleartic
Presence:
Extant
Origin:
Endemic Canaries
Seasonality:
Resident

Population:

There is no information available on the population size or trend of this species. Field observation show that the species is rare and hard to find alive.

Habitat and Ecology

There are no specific habitat type in the literature, however, it is nearly always sympatric with T. geminata. (Shells of T. geminata occur in great abundance locally on the islet Graciosa. T. geminata and T. impugnata are sympatric on northern Lanzarote and on Graciosa. Where the two species are found together they are about equally common). This species probably lives in the dry temperate shrub vegetation (Piso basal).

Major Threat(s):

There are some threats to this species by goat grazing and tourist activities. The Riscos are a well known recreation spot with barbecue sites, miradors, and similar infrastructure.

Conservation Actions

There is no conservation action in place for this species.