Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Stylommatophora Hygromiidae

Scientific Name: Xerotricha gasulli
Species Authority: (Ortiz de Zarate, 1950)
Helicella gasulli Ortiz de Zarate, 1950
Taxonomic Notes: Some authors consider this species must be included in the genus Helicella instead of Xerotricha (Giusti and Manganelli 1989, Arrébola 1995).

Assessment Information [top]

Red List Category & Criteria: Endangered B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) ver 3.1
Year Published: 2013
Date Assessed: 2010-08-29
Assessor(s): Arrébola, J.
Reviewer(s): Gómez, B., Martínez-Ortí, A., Neubert, E., Seddon, M.B., Cuttelod, A. & Lutz, M.L.
The strong development in agriculture, both extensive and intensive and all its secondary effects, has displaced this species from where it was formerly distributed. In 2008, 61 localities were sampled, including the four where the species had been previously cited, in order to define the range of the species and its threatened status. However, no individuals were found (Arrébola, Díaz, Ruiz and Puente 2008). Urgent actions are needed to try to rescue this species. It is currently listed as Endangered (EN) B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v), however if future surveys fail to find this species, it might need to be upgraded to Critically Endangered (CR) or possibly even Extinct (EX).
Previously published Red List assessments:
1996 Lower Risk/near threatened (LR/nt)

Geographic Range [top]

Range Description: This Spanish endemic is known from only three locations (four records): two in the province of Seville and one, the type locality, in the province of Málaga. The three locations are far from each, delimiting a quite fragmented range.
Countries occurrence:
Spain (Spain (mainland))
Estimated area of occupancy (AOO) - km2: 300
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2: 2644
Continuing decline in extent of occurrence (EOO): Yes
Number of Locations: 3
Upper elevation limit (metres): 150
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: There are no population data about this species. However, it is possible to infer a strong and continuous decline over the several decades (loss of habitat).
Current Population Trend: Decreasing
Additional data:
Continuing decline of mature individuals: Yes
Population severely fragmented: No
Continuing decline in subpopulations: Yes

Habitat and Ecology [top]

Habitat and Ecology: The appropriate habitat of this species is not very well known. The three locations where it was sampled were strongly modified by human activities: one in the margins of cultivated land and two in erial. The two locations in Sevilla are situated in the agricultural regions "La Campiña" and "La Vega", a large expanse of land almost fully occupied by different crops. So, it seems that X. gasulli only survives in those places where the agricultural influence allows it.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes

Use and Trade [top]

Use and Trade: This species is not used.

Threats [top]

Major Threat(s): The main threat is the strong development in agriculture, both extensive and intensive, and all its secondary effects, that occurred in the area where this species was formerly distributed. In 2008, 61 localities were sampled, including the four where the species had been previously cited, in order to define the range of this species and its threatened status.  No individual was found (Arrébola et al. 2008).

Conservation Actions [top]

Conservation Actions: Urgent actions are needed to try to save this species, including captive breeding, reintroduction, protection and management of its habitat, etc. It is included in the "Conservation and Sustainable Use of Andalusian Snails Program" promoted by the Andalusian Regional Ministry of Environment (Junta de Andalucía). This species was firstly classified as Endangered (EN) in the Spanish Red Book of Invertebrates Invertebrates (Verdú and Galante 2006) and the Red Book of Andalusian Invertebrates (Arrébola and Ruiz 2008), but later it was proposed as Critically Endangered (CR) in the Atlas of the Spain Threatened Invertebrates (Arrébola, Díaz, Ruiz and Puente 2008) .

Citation: Arrébola, J. 2013. Xerotricha gasulli. The IUCN Red List of Threatened Species 2013: e.T9793A13016353. . Downloaded on 09 October 2015.
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