BackTheba geminata (Mousson, 1857)

Theba geminata (Mousson, 1857)

  • Kingdom: Animalia
  • Phylum:
  • Class: Mollusca
  • Order: Gastropoda
  • Family: Helicidae
DD Data Deficient
IUCN Red List Status:

Countries of Occurrence:
Spain - Canaries


Groh, K. & Neubert, E.

Cuttelod, A. & Bilz, M.

George, S.

Facilitators / Compilers/s:

Assessment Rationale:

This is most probably a species complex, which urgently needs scientific research (Greve et al. 2010). For this reasons it is impossible to assess any conservation status, the complex is thus listed as Data Deficient (DD).

Geographic Range:

T. geminata is a common species-complex on the Canary Islands. On Lanzarote, at least two species exist under that taxon name, one of them is yet undescribed and also occurs on Furteventura and on Tenerife (Greve et al. 2010: Theba sp. 1) and further research will lead most probably to further species within that complex. At least three additional undescribed species are known to La Gomera and to Lanzarote and another three new species to Fuerteventura (Greve at al. 2010).  Distribution maps for the complex are given in Alonso et al. (1990), and Ibanez and Alonso (2001). Individuals have been taken from the following specific locations on the Canary Islands, these were recorded in 1987 (Gittenberger and Ripken 1987):


Lanzarote:  Isla Graciosa, Orzola, Jameos dei Agua, Haría, los Valles, Bajamar (Tías), Playa de Famara, El Mojón, Montana de las Nuevas, Castillo de Guanapay, Tinajo, Tiagua, Teguise, Mozaga, Mozaga, Yaiza, Playa de Janubio, Playa Blanca, Playa Blanca, Punta dei Papagayo, Isla de Lobos. 


Fuerteventura: Corallejo, La Oliva, Montaria Muda, Playa dei Matorral, Los Molinos, Betancuria, Vega dei Rio de Palmas, Barranco Morra Fénduca, Toto, Cortijo de Chilegua, Playa de Ugán, Gran Tarajal, Istmo de la Pared, Morro Jable, Cofete, Punta de Gandia.


 Tenerife: Bajamar Buenavista, Los Silos, La Palma, Gomera, Hierro: Sabinosa (to be confirmed).

Spain - Canaries
Extent of Occurrence (EOO):
Area of Occupancy (AOO):
Elevation Lower Limit:
Elevation Upper Limit:
Biogeographic Realms:
Endemic Canaries


The size and trend within the subpopulations are supposed to be stable.

Habitat and Ecology

This species lives in the dry temperate shrub vegetation (Piso basal).

Major Threat(s):

Theba geminata has been seen to be predated on by feral cats (Medina et al. 2008) but whether this has a significant effect on the population will have to be researched further due to no data. Once the species complex is unravelled taxonomically it may turn out that single species have very small distribution areas. These might then be affected by urbanization, agriculture – especially goats – tourist industry, road construction, etc.

Conservation Actions

There are no conservation actions. More research is needed on the taxonomy of this species-complex and on the exact distribution and population.