Dlinza pinwheel  (Trachycystis clifdeni)

Dlinza pinwheel

Facts

Also known as:Dlinza forest pinwheel
Kingdom Animalia
Phylum Mollusca
Class Gastropoda
Order Stylommatophora
Family Charopidae
Genus Trachycystis (1)
Size Diameter: up to 9.7 mm (2)

Status

Classified as Critically Endangered (CR) on the IUCN Red List 2006 (1).

Description

This exceptionally striking snail immediately stands out for the unusual whorl of bristles that radiate out from the edge of its shell, somewhat resembling the pinwheel firework after which it is named. The fragile, almost translucent pale-brown shell is a spiral shape with up to five whorls, sculptured with widely spaced axial riblets (2).

Range

Known only from Dlinza Forest, in the province of KwaZulu-Natal, South Africa, which covers an area of just c. 250 hectares (1) (2).

Habitat

This unique snail is found in coastal scarp forest (1) beneath leaves of understorey vegetation, under fallen logs, in leaf-litter, and occasionally in damp swampy areas (2).

Biology

Nothing is known of the Dlinza pinwheel's reproductive biology, life history patterns or feeding behaviour.

Threats

The Dlinza Forest is officially protected and is under the control of Ezemvelo KwaZulu-Natal Wildlife (1) (3). However, the forest's location within an urban environment does give some cause for concern. Furthermore, its very limited distribution means that it is highly vulnerable to the damaging effects of extreme stochastic weather conditions and climate change (1).

Conservation

The fact that Dlinza Forest is an officially protected area, supported by an enthusiastic local community, does confer a degree of protection to this Critically Endangered species. Nevertheless, the small and exposed nature of its home means that this rare and fascinating snail remains somewhat helpless to the changing world around it (1). More research into the ecology and behaviour of this small but captivating species may help unearth valuable information to help guide appropriate conservation action and bring the diminutive ‘pinwheel' back from the brink of extinction.

Further Information

For more information on the Dlinza pinwheel see:

  • Herbert, D.G. & Kilburn, R.N. (2004) Field guide to the land snails and slugs of eastern South Africa. 340pp. Natal Museum, Pietermaritzburg.
  • IUCN Red List:
    http://www.iucnredlist.org

Authentication

Authenticated (13/07/2006) by Dr. Dai G. Herbert, Chief Curator: Mollusca, Natal Museum, and member of the IUCN/SSC Southern African Invertebrate, and Mollusc Specialist Groups.
http://www.nmsa.org.za/

Endemic: A species or taxonomic group that is only found in one particular country or geographic area.
Scarp: An escarpment, cliff, or steep slope of some extent along the margin of a plateau or ridge.
Stochastic: Random, uncertain or unpredictable.
Whorl: In molluscs,the spiral coils of the shell of a snail.

References

  1. IUCN Red List (June, 2006)
    http://www.iucnredlist.org
  2. Inland Invertebrate Initiative: Database of Threatened Invertebrates of South Africa (June, 2006)
    http://www.ukzn.ac.za/redlist/detail_page.asp?id=210
  3. Herbert, D. (2006) Pers. Comm.