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Aaadonta fuscozonata ssp. depressa

Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_offStatus_en_offStatus_cr_onStatus_ew_offStatus_ex_off

Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA MOLLUSCA GASTROPODA STYLOMMATOPHORA ENDODONTIDAE

Scientific Name: Aaadonta fuscozonata ssp. depressa
Species Authority: Solem, 1976
Parent Species:

Assessment Information [top]

Red List Category & Criteria: Critically Endangered B1ab(i,ii,iii)+2ab(i,ii,iii) ver 3.1
Year Published: 2012
Date Assessed: 2011-08-22
Assessor(s): Rundell, R.J.
Reviewer(s): Seddon, M., Barker, G. & Pippard, H.
Justification:

Aaadonta fuscozonata depressa is a minute ground-dwelling snail for which only one live shell was found at a single locality on Ngemelis in 2005. The subspecies was previously known only from Peleliu, where three specimens were collected at two localities in 1936 by Y. Kondo. However, no specimens were found on this island in recent surveys. The species is listed as Critically Endangered, based on the limited area of occupancy, the single location, and a decline in its native habitat. Surveys to determine the current distribution of this species and population size, status and trends are recommended.

Geographic Range [top]

Range Description:

The historical geographic range of A. fuscozonata depressa was 12km2. The subspecies was previously known only from Peleliu, where three specimens were collected at two localities in 1936 by Y. Kondo. The species was probably historically more abundant prior to this - indeed, substantial change had already occurred on that island by that time. The area of occupancy for this subspecies is now estimated at 1km2, since few specimens have been found recently at a single locality on Ngemelis, a smaller nearby island.

Countries:
Native:
Palau
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: This subspecies was previously known only from Peleliu, where three specimens were collected at two localities in 1936 by Y. Kondo (Solem 1976). Only one live shell was found at a single locality in 2005 (R.J. Rundell, 2005, unpublished data) on Ngemelis. However, no specimens were found on Peleliu in recent surveys. (Rundell 2003 unpublished data, Rundell 2005 and 2010).
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This is a ground dwelling species recorded from tropical moist lowland forest.
Systems: Terrestrial

Use and Trade [top]

Use and Trade: This species is not utilized.

Threats [top]

Major Threat(s):

A. fuscozonata depressa is threatened by destruction and modification of native lowland forest. Therefore it is not surprising that the subspecies has probably been extirpated from the highly modified island of Peleliu, whose forest was burned in World War II with flamethrowers (Hinz 1995; Crombie and Pregill 1999). Disruption of the ground, rocks and leaf litter may be of particular significance to this and other endodontid species. Endodontoid land snails are among the most threatened land snails on Pacific Islands in the few places where they still exist (Solem 1983), and therefore the fact that this subspecies is still extant is important. This subspecies is in need of conservation attention.

Conservation Actions [top]

Conservation Actions:

Field work to define the current distribution of this species, as well as research on its population status and trends, is required. Identification of priority sites for species conservation (e.g. key biodiversity areas that include threatened land snails) and reducing the impacts of human activities, especially on the small islands, is also urgently needed. The Palau Conservation Society has been supportive of recent land snail survey work in Palau.


Citation: Rundell, R.J. 2012. Aaadonta fuscozonata ssp. depressa. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 19 December 2014.
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