| Aldabra banded snail | |
|---|---|
| Drawing of the shell of Rhachistia aldabrae | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Gastropoda |
| (unranked): | clade Heterobranchia
clade Euthyneura |
| Superfamily: | Enoidea |
| Family: | Cerastidae |
| Genus: | Rhachistia |
| Species: | † R. aldabrae |
| Binomial name | |
| † Rhachistia aldabrae (von Martens, 1898)[2] |
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| Synonyms | |
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The †Aldabra banded snail, scientific name Rhachistia aldabrae, was a species of land snail, a pulmonate gastropod mollusc in the family Cerastidae. It lived on one atoll in the Seychelles Islands, Indian Ocean, and was easily recognizable because of its purplish blue banded shell. The species is thought to have died out because of climate change.[3]
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The shell of this snail was very unusual in its coloring: purple, indigo blue, and orange, and this made the snail very easy to recognize and identify. The Aldabra snail grazed on algae and thus was very low on the food chain.[4]
The shell is oblong, ovate-conical, rather thick, slightly striated, glossy, in the upper part is pale, in the lower part it is black brown.[2] The shell has seven slightly curved and regularly increasing whorls.[2] The upper 3-4 whorls are blackish, the following are dim bluish.[2]
The Aldabra banded snail was endemic to Aldabra Atoll in the Indian Ocean. In 1906 it was the most common snail species on the atoll.[5][6]
After 1976 however, only adult snails were found on Aldabra, and no live individuals have been found at all since 1997.[3] Researchers believe that this species became extinct during the late 1990s, after a series of unusually long, hot, and dry summers caused by climate change. These summers appear to have killed off a large number of the younger snails.[7]
The habitat of this snail suffered a sudden decline in rainfall, which was essential to the survival of this species, and this dryness appears to have caused its extinction.
This article incorporates public domain text from the reference [2].