Tag Archives: Partula faba

Partula faba ssp. faba (Gmelin)

Bean-shaped Tree-Snail (Partula faba ssp. faba)

The Bean-shaped Tree-Snail was described in 1791, being the first species of its genus to be described.

The species inhabited the sister islands of Ra’iatea and Taha’a, Society Islands, with both islands harbouring an endemic subspecies respectively. It was extremely abundand in former times and was found everywhere on the islands from the sea level to the highest peaks.

The great variability of the shell coloration led to the description of various ‘varieties’. [1]

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The Bean-shaped Tree-Snail was heavily declining in the 1990s after the Rosy Wolf-Snail (Euglandina sp.) had been introduced to and established on the island. 

In an effort to save this species from extinction as much as 89 individuals were collected in 1991 and brought into captivity to be bred. One year later, in 1992, one last surviving individual was found and collected in the Vaiapu Valley, another 65 individuals were found and collected on the Temehani Plateau also to be brought into captivity – this was the last time the species was ever seen in the wild.

These last known individuals did well in captivity and even readily produced offspring and the future prospects for the this partulid species appeared to be good, however, the individuals born in captivity did not produce that much offspring, and the following generations finally produced none at all and the number of individuals dwindled. 

The last surviving individuals were kept in several Zoos in Great Britain, including the Zoos of Bristol and London, but the number still dropped and dropped to only two remaining individuals in 2015. These last two survivors of their species were finally brought to the Zoo of Edinburgh, who had the greatest experiences with breeeding endangered partulid snails, however, this was unsuccessful.

The very last individual finally died today, February 21th, 2016, making it the 34th partulid species to have become extinct within the last 20 years. [1] 

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References:

[1] Justin Gerlach: Icons of Evolution: Pacific Island Tree-Snails of the Family Partulidae. Phelsuma Press 2016

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Photo: Naturalis Biodiversity Center  
https://www.naturalis.nl

(no copyright)  

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edited: 29.04.2019