Aaadonta fuscozonata ssp. fuscozonata
|Scientific Name:||Aaadonta fuscozonata ssp. fuscozonata (Beddome, 1889)|
|Red List Category & Criteria:||Critically Endangered D ver 3.1|
|Reviewer(s):||Seddon, M., Barker, G. & Pippard, H.|
The subspecies was previously known only from Koror, where it was collected at a single locality in 1936 by Y. Kondo. In recent surveys, only nine live specimens have been found, from four distinct and tiny Rock Islands (four localities). The subspecies is listed as Critically Endangered, based on the limited area of occupancy (approximately 2km2) and the very small number of specimens that have been found recently, despite surveys of available native habitat. The species is also found in areas where habitat quality and quantity is in decline. Site protection is recommended, as are surveys to determine the current distribution of this species and population size, status and trends.
This is a minute ground-dwelling snail historically known from the island of Koror (Oreor) in Palau. Its historical geographic range is estimated at 7km2 based on occupancy of a small area of Koror. The species was probably historically more abundant prior to its collection at only a single locality in 1936. In recent surveys (Rundell 2010), the subspecies was found in very small areas on very small islands, and its current area of occupancy is estimated as 2km2.
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Only few live shells (nine) were found in 2007 (R.J. Rundell 2007, unpublished data) on four northern Rock Islands in four localities on those islands. However, no specimens were found on the island from which the subspecies was described (Koror) in 2003, 2005 or 2007 surveys (R.J. Rundell 2007 unpublished data, Rundell 2005 and 2010).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||This is a ground dwelling snail found in moist lowland forest.|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||This species is not utilized.|
A. fuscozonata fuscozonata is 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).
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.
Colin, PL. 2009. Marine Environments of Palau. Indo-Pacific Press, San Diego.
Cowie, RH, Allison, A, Howarth, FG, Samuelson, GA, Evenhuis, NL. 1996. Impacts of the Palau Compact Road: Survey of the non-marine fauna of the Island of Babeldaob. Will Chee Planning, Honolulu.
Crombie, R.I. and Pregill, G.K. 1999. A checklist of the herpetofauna of the Palau Islands (Republic of Belau), Oceania. Herpetological Monographs 13: 29-80.
Hinz, E. 1995. Pacific Island Battlegrounds of World War II: Then and Now. The Bess Press, Honolulu.
IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.2). Available at: http://www.iucnredlist.org. (Accessed: 17 October 2012).
Motteler, LS. 2006. Pacific Island Names. Bishop Museum Press, Honolulu.
Rundell, RJ. 2005. The land snails of Belau: Survey of the 16 states.
Rundell, RJ. 2008. Cryptic diversity, molecular phylogeny and biogeography of the rock- and leaf litter-dwelling land snails of Belau (Republic of Palau, Oceania). Philosophical Transactions of the Royal Society of London B 363: 3401-3412.
Rundell, RJ. 2010. Diversity and conservation of the land snail fauna of the western Pacific islands of Belau (Republic of Palau, Oceania). American Malacological Bulletin 28: 81-90.
Smith, B.D. 1993. Working list of the terrestrial gastropods of Palau, Caroline Islands. Working List No. 4. Dickinson Memorial Mollusc Collection, Marine Laboratory, University of Guam.
Solem, A. 1976. Endodontoid land snails from Pacific islands (Mollusca: Pulmonata: Sigmurethra). Part I. Family Endodontidae. Field Museum of Natural History, Chicago.
Solem, A. 1983. Endodontoid land snails from Pacific islands (Mollusca: Pulmonata: Sigmurethra). Part II. Families Punctidae and Charopidae. Zoogeography. Field Museum of Natural History, Chicago.
|Citation:||Rundell, R.J. 2012. Aaadonta fuscozonata ssp. fuscozonata. The IUCN Red List of Threatened Species 2012: e.T198787A2535087.Downloaded on 25 November 2017.|
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