Rhachistia aldabrae Martens, 1898

Aldabra banded snail



Taxonomy & Nomenclature



Conservation Status

Last record: 1997 (Gerlach, 2007)

Rediscovered in 23 August 2014

IUCN RedList status: Extinct


The reported decline and subsequent disappearance of the species has been reported to be due to climate change (Gerlach, 2007). But the declaration of the species' extinction was viewed as premature by some (Hambler et al., 2007), and it was subsequently rediscovered (Battarbee, 2014). A new preprint also questions the cause of the species original decline (Altaba, 2022).



Aldabra Atoll, Seychelles


Biology & Ecology










Altaba, Cristian R. (2022). Extinction through Climate Change: Review of Evidence and Analysis of Two Land Snails from the Seychelles Islands. Preprints 2022100315 (

Battarbee, Richard W. (2014). The rediscovery of the Aldabra banded snail, Rhachistia aldabrae. Biology Letters 10:  20140771.

Commentary by Rhett A. Butler, (August 12, 2007). Climate change claims a snail.

Cowie, Robert H., Régnier, Claire, Fontaine, Benoît, and Bouchet, Philippe. (2017). Measuring the Sixth Extinction: what do mollusks tell us? The Nautilus 131(1): 3-41.

Fryer, J. C. F. (1911). The structure and formation of Aldabra and neighbouring islands—with notes on their flora and fauna. Trans. Linn. Soc. Lond. Ser. 2: Zool 14: 401-442.

Gerlach, Justin. (2006). Terrestrial and freshwater Mollusca of the Seychelles Islands. Leiden, The Netherlands: Backhuys Publishers.

Gerlach, Justin. (2007). Short-term climate change and the extinction of the snail Rachistia aldabrae (Gastropoda: Pulmonata). Biology Letters 3: 581-585.

Gerlach, Justin. (2009). Rhachistia aldabrae. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.2. ( Downloaded on 01 June 2013.

Gerlach, Justin. (2012). Red Listing reveals the true state of biodiversity: a comprehensive assessment of Seychelles biodiversity. Phelsuma 20: 9-22.

Hambler, Clive et al. (2007). “Extinction” of Rhachistia aldabrae contested. Unpublished manuscript. [automatic download]

Holmes, Branden. (2021). What's Lost and What Remains: The Sixth Extinction in 100 Accounts (eBook). Self published.

Régnier, Claire, Fontaine, Benoît and Bouchet, Philippe. (2009). Not Knowing, Not Recording, Not Listing: Numerous Unnoticed Mollusk Extinctions. Conservation Biology 23(5): 1214-1221.


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