Pachnodus oxoniensis 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Stylommatophora Cerastidae

Scientific Name: Pachnodus oxoniensis
Species Authority: Gerlach, 1994

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(iii)+2ab(iii) ver 3.1
Year Published: 2009
Date Assessed: 2006-01-11
Assessor(s): Gerlach, J.
Reviewer(s): Miller, R.M., Pollock, C.M. & Seddon, M.B.
This species is restricted to a very small range; its EOO and AOO are both estimated to be 3 km², and it is found in only 1 location. Within this area the population is stable, but vulnerable to habitat deterioration and habitat change resulting from climate change (changes in rainfall patterns), as well as ongoing habitat degradation caused by the impacts of invasive alien plant species (e.g., Cinnamomum verum).

Geographic Range [top]

Range Description: A Seychelles endemic, this snail is known only from Silhouette island and has an estimated extent of occurrence (EOO) and area of occupancy (AOO) of just 3 km².
Countries occurrence:
Seychelles (Seychelles (main island group))
Estimated area of occupancy (AOO) - km2: 3
Continuing decline in area of occupancy (AOO): No
Extreme fluctuations in area of occupancy (AOO): No
Estimated extent of occurrence (EOO) - km2: 3
Continuing decline in extent of occurrence (EOO): No
Extreme fluctuations in extent of occurrence (EOO): No
Number of Locations: 1
Continuing decline in number of locations: No
Extreme fluctuations in the number of locations: No
Lower elevation limit (metres): 450
Upper elevation limit (metres): 774
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Population estimates showed 423,000 individuals in 2005.
Current Population Trend: Stable
Additional data:
Number of mature individuals: 423000 Continuing decline of mature individuals: No
Extreme fluctuations: No Population severely fragmented: No
Continuing decline in subpopulations: No
Extreme fluctuations in subpopulations: No All individuals in one subpopulation: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This is an arboreal species restricted to high moss forest, above 450 m.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes

Threats [top]

Major Threat(s): Pachnodus oxoniensis is vulnerable to habitat deterioration and habitat change resulting from climate change (changes in rainfall patterns), as well as habitat degradation caused by the impacts of invasive alien species (e.g., Cinnamomum verum).

Conservation Actions [top]

Conservation Actions: No conservation measures are in place. The forest areas of Silhouette should be protected, and invasive species must be controlled throughout the Seychelles.

Citation: Gerlach, J. 2009. Pachnodus oxoniensis. The IUCN Red List of Threatened Species 2009: e.T168119A6454126. . Downloaded on 30 November 2015.
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