Tag Archives: Bulimulus adelphus Dall

Naesiotus adelphus Dall

Adelphus’ Galapagos Snail (Naesiotus adelphus)

Adelphus’ Galapagos Snail, described in 1917, is endemic to the Isla Santa Cruz, Galápagos Islands, where it inhabited the island’s arid zones. [1]  

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Robert P. Smith, a gastropod specialist, investigated the snail populations on six of the larger islands of the Galápagos archipelago in 1970, including Isla Santa Cruz. By 2005 and 2005, when exactly the same areas were investigated again, many populations had disappeared.  

The touristic industry is booming on the islands, particularly on Isla Santa Cruz, and many of the former habitats are destroyed today, not only by development but also by the introduction of foreign species (animals and plants).  

The highlands, formerly home to endemic species like the Galapagos Miconia (Miconia robinsoniana Cogn.) and the Santa Cruz Scalesia (Scalesia pedunculata Hook. F.) are now overrun by introduced plant species, just like the lower regions of the island are.  

The snails are also killed by introduced ants, especially by the Little Fire Ant, also known as Electric Ant, (Wasmannia auropunctata (Roger)). [2][3]

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Adelphus’ Galapagos Snail was not found in recent years, despite specific searches, and is considered most likely extinct.  

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References:  

[1] William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928 
[2] Christine E. Parent; Robert P. Smith: Galápagos bulimulids: status report on a devastated fauna. Tentacle 14. 2006
[3] Christine E. Parent; Bernard J. Crepsi: Sequential colonization and diversification of Galapágos endemic land snail genus Bulimulus (Gastropoda, Stylommatophora). Evolution 60(11): 2311-2328. 2006  

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Photo from: ‘William Healey Dall; Washington Henry Ochsner: Landshells of the Galapagos Islands. Proceedings of the California Academy of Sciences. Ser. 4. Vol. 17.: 141-185. 1928’

(under creative commons license (3.0))
https://creativecommons.org/licenses/by-nc-sa/3.0/

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edited: 01.06.2021