Aaadonta constricta ssp. komakanensis 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Gastropoda Stylommatophora Endodontidae

Scientific Name: Aaadonta constricta ssp. komakanensis
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: 2011-08-24
Assessor(s): Rundell, R.J.
Reviewer(s): Barker, G., Seddon, M. & Pippard, H.

This is a minute ground-dwelling snail for which no shells (live or dead) have been found in recent years, despite recent extensive surveys of its island habitat of Koror. The subspecies was previously known only from Koror, where it was collected at a single locality in 1936 by Y. Kondo. The species is listed as Critically Endangered (Possibly Extinct) due to a very small and declining extent of occurrence and area of occupancy, the species being found in a single location, and a decline in availability and quality of its habitat. Additional surveys of the island are needed to verify whether the subspecies is in fact Extinct, but based on extinctions of endodontids elsewhere in the Pacific, as well as other extirpations of endemic land snails on Koror, optimism is low.

Geographic Range [top]

Range Description:

This is a minute ground-dwelling snail that was historically known from the island of Koror (Oreor), where it was collected at a single locality in 1936 by Y. Kondo (Solem 1976). The historical geographic range was less than 20km2, and probably only approximately 7km2 (R. Rundell pers.comm. 2011). The species was probably historically more abundant prior to its collection at only a single locality in 1936.

Countries occurrence:
Possibly extinct:
Estimated area of occupancy (AOO) - km2: 0
Continuing decline in area of occupancy (AOO): Yes
Estimated extent of occurrence (EOO) - km2: 7
Continuing decline in extent of occurrence (EOO): Yes
Number of Locations: 1
Lower elevation limit (metres): 1
Upper elevation limit (metres): 200
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: Aaadonta constricta komakanensis is a minute ground-dwelling snail for which no shells (live or dead) have been found in recent years, despite surveys of its island habitat of Oreor (“Koror”) in 2003, 2005 and 2007 (R.J. Rundell 2007 unpublished data; Rundell, 2005, 2010). The subspecies was previously known only from Oreor, where it was collected at a single locality in 1936 by Y. Kondo (Solem 1976: 478).
Current Population Trend: Unknown
Additional data:

Habitat and Ecology [top]

Habitat and Ecology: This is a ground-dwelling snail recorded from moist lowland forest.
Systems: Terrestrial
Continuing decline in area, extent and/or quality of habitat: Yes

Use and Trade [top]

Use and Trade: This species is not utilized.

Threats [top]

Major Threat(s):

A. constricta komakanensis is (or was) threatened by destruction and modification of native lowland forest. Therefore it is not surprising that the species has probably been extirpated from the highly modified and deforested island of Koror. 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).

Conservation Actions [top]

Conservation Actions: This species is not protected. 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 constricta ssp. komakanensis. The IUCN Red List of Threatened Species 2012: e.T198785A2534908. . Downloaded on 30 November 2015.
Disclaimer: To make use of this information, please check the <Terms of Use>.
Feedback: If you see any errors or have any questions or suggestions on what is shown on this page, please provide us with feedback so that we can correct or extend the information provided