Tag Archives: Partula

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

Partula dentifera ssp. imperforata (Garrett)

Unperforated Tree-Snail (Partula dentifera ssp. imperforata)  

This form was described in 1884, originally as a distinct species.  

The Unperforated Tree-Snail was endemic to the island of Ra’iatea, Society Islands, where it inhabited the Mt. Tefatua, as well as many of the smaller valleys on the western side of the island at elevations from sea-level to about 700 m.  

This form differs from the nominate form by several characters, for example by its narrower umbilicus, which sometimes is fully closed. [1]  

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The Unperforated Tree-Snail, like all its congeners from the lowland areas of Ra’iatea, is now extinct.  

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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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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

(public domain) 

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edited: 21.10.2017

Partula dentifera ssp. formosa (Garrett)

Beautiful Tree-Snail (Partula dentifera ssp. formosa 

This subspecies was described in 1884, originally as a distinct species.  

The Beautiful Tree-Snail was endemic to the southwestern part of Ra’iatea, Society Islands, where it inhabited several valleys, including the Faaroa, the Faatemu, the Tivae, the Vaeanae, and the Vaiaau valleys. It was an arboreal form and was usually found on shrubs. [2]  

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The following citation about this species in life is from Andrew Garrett.:  

The metropolis of this very distinct species is in Fatimu, or on the southwest part of Raiatea. It occurs in vast numbers on bushes on the lowlands near the seashore, becoming more scarce inland, where it is found associated with P. Hebe, var. bella. It ranges north as far as Vaiau valley, becoming less and less abundant as the distance increases from its specific centre.” [1]  

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The shells of this rather large form reached a height of about 2,5 cm.  

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References:  

[1] Andrew Garrett: The terrestrial Mollusca inhabiting the Society Islands. Philadelphia: Academy of Natural Sciences of Philadelphia 1884 [2] Justin Gerlach: Icons of Evolution: Pacific Island Tree-Snails of the Family Partulidae. Phelsuma Press 2016  

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’ 

(public domain)

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edited: 21.10.2017

Partula cytherea Cooke & Crampton

Mountain Tree-Snail (Partula cytherea 

This species, named with another name of the Greek goddess Aphrodite, was described in 1930.  

The Mountain Tree-Snail is known only from the upper slopes of the three highest mountains on the island of Tahiti, Mt. Aorai, Mt. Marau, and Mt. Orohena.  

The species was arboreal, living on ferns and shrubs, mainly on the leaves of lower trees.  

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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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edited: 18.10.2017

Partula desolata Baumann & Kerr

Desolate Tree-Snail (Partula desolata)

This species was described in 2013 based on subfossil shells that were recovered from Holocene deposits on the island of Rota, Mariana Islands.

The species occurred sympatrically with the Humped Tree-Snail (Partula gibba Férussac), which, however, still survives until today.

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References:

[1] Scott Baumann; Alexander M. Kerr: Partula desolata sp. nov. (Pulmonata: Partulidae), an extinct land snail from Rota, Mariana Islands, micronesia. Micronesica 5: 1-2. 2013

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edited: 18.06.2019

Partula lutea (Lesson)

Yellow Tree Snail (Partula lutea)  

This variably colored species was described in the year 1831.  

The species was endemic to the island of Bora Bora, Society Islands, where it was the only member of its genus, and where it was still numerously found in the 19th century on the stems, branches, and leaves of the native vegetation.  

The shells reached a height of nearly 2 cm and was usually pale yellowish to light brown with the apex being of the same color or slightly darker.  

The Yellow Tree-Snail is now extinct. [1]  

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The same species was introduced to the island of Maupiti sometimes after 1929, from where it is known, however, only from subfossil shells, found and photographed in 2010, 2012 and 2017 by J.-F. Butaud, J. Gerlach and others.  

The species is extinct on Maupiti as well. [1][2]  

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References:  

[1] Justin Gerlach: Icons of Evolution: Pacific Island tree-snails, family Partulida, Phelsuma Press, Cambridge U.K. 2016 
[2] Justin Gerlach: Partula survival in 2017, a survey of the Society Islands  

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Photo: Alexander Lang 

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edited: 18.05.2019

Partula dolorosa Crampton & Cooke

Temehani Tree-Snail (Partula dolorosa)  

This species was described in 1953.  

The Temehani Tree-Snail was endemic to the island of Ra’iatea, Society Islands, where it was apparently restricted to the Temehani Plateau.  

The species was arboreal and was usually found sitting on the leaves of native screw pines (Pandanus spp.). [1]  

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The Temehani Tree-Snail appears to have been found in 1992 for the last time, and is extinct since.  

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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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edited: 21.10.2017

Partula producta Pease

Faarahi Tree-Snail (Partula producta)  

This species was described in 1865.  

The species was endemic to the island of Tahiti, Society Islands, where it was very abundant at the time of its discovery and description, and inhabited several valleys, including Apirimaue, Faarahi, Faone, Papeiti, Taharua, Temarua, Tereehia, Titaviri, Vaihiria, Vairaharaha, Vaitunamea.  

The species was mainly terrestrial, living beneath decaying leaves and among stones etc..  

The shells reached sizes of about 1,8 to 2,1 cm, there was some slight geographical variation, but most specimens were light brown with darker stripes. [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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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

(public domain)

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edited: 21.10.2017

Partula dentifera ssp. callifera (Pfeiffer)

Callus-carrying Tree-Snail (Partula dentifera ssp. callifera)  

This form was described in 1856, originally as a distinct species.  

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The following citation about this species in life is from Andrew Garrett.:  

A well-characterized species, restricted to the higher portion of Haamoa valley, on the east coast of Raiatea, where it is not uncommon on foliage. It may be easily determined by its creamy white color, yellow apex, constant parietal tooth, inflated body-whorl, oval or rounded “key-hole” aperture, conspicuous labial tooth and the total absence of epidermis in the adult shells. It is never banded.” [1]  

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The shells reached a height of 1,7 to 2,1 cm, they differed from the nominate race in several characters, for example in being more ovate, having an inflated body-whorl and a more open umbilicus. [2]  

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The species died out for the same reasons as all the other extinct Polynesian tree-snail species.  

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References:  

[1] Andrew Garrett: The terrestrial Mollusca inhabiting the Society Islands. Philadelphia: Academy of Natural Sciences of Philadelphia 1884 
[2] Justin Gerlach: Icons of Evolution: Pacific Island Tree-Snails of the Family Partulidae. Phelsuma Press 2016  

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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

(public domain) 

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edited: 21.10.2017

Partula diminuta C. B. Adams

Small Tree-Snail (Partula diminuta)  

This species was described in 1851.  

The Small Tree-Snail was restricted to the Pirae valley in northwestern Tahiti, Society Islands, which is now largely cleared for agriculture.  

The species appears to have been last recorded in 1970, when it was already restricted to the uppermost parts of its former range. It is now extinct.  

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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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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’

(public domain)

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edited: 21.10.2017

Partula garretti Pease

Garrett’s Tree-Snail (Partula garretti 

Garrett’s Tree-Snail was described in 1865, it includes three subspecies of which the nominate, discussed here, was restricted to the central range of northeastern Ra’iatea, Society Islands.

The species, like all Raiatean partulid species, is extinct. [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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Depiction from: ‘George W. Tryon; Henry A. Pilsbry; a.o.: Manual of Conchology. Second Series: Pulmonata Vol. 20, Caecilioides, Clessula and Partulidae. Index to Vols. 16-20. 1909-1910’ 

(public domain)

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edited: 30.04.2019

Partula cuneata Crampton

Wedge-shaped Tree-Snail (Partula cuneata)  

The Wedge-shaped Tree-Snail was described in 1956.  

The species was endemic to the island of Ra’iatea, Society islands, where it was restricted to the Ere’eo Valley on the west coast of the island, which it shared with five additional tree-snail species – all of them now extinct. [1][2]

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References:

[1] Henry E. Crampton: New Species of Land Snails of the Genus Partula from Raiatea, Society Islands. American Museum Novitates 1761: 1-17. 1956
[2] Justin Gerlach: Icons of Evolution: Pacific Island Tree-Snails of the Family Partulidae. Phelsuma Press 2016

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edited: 30.04.2019

Partula sagitta Crampton & Cooke

Arrow-shaped Tree-Snail (Partula sagitta)  

This species was described in 1953.  

The Arrow-shaped Tree-Snail was apparently restricted to a single locality at about 230 m in the Hamene valley at the slopes of Mt. Purauti in the center of Taha’a, Society Islands, where it was only ever found by the “Mangareva Expedition” in 1934.  

The species is now clearly extinct.  

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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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edited: 18.10.2017

Partula aurantia Crampton

Golden Tree-Snail (Partula aurantia)  

This species was described in 1932.  

The species was endemic to the eastern part of Mo’orea, Society Islands, where it inhabited several valleys, including the Faamaariri valley, the Paraoro valley and the Vaipohe valley.  

The Golden Tree-Snail was an arboreal species and was often found on the leaves of the epiphytic fara pape (Freycinetia demissa Benn.). [1]  

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The species is now extinct, the reasons for its extinction are the same as for the other Polynesian tree-snail species.  

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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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edited: 18.10.2017

Partula levistriata Crampton

Striated Tree-Snail (Partula levistriata 

This arboreal species was described in 1956.  

The Striated Tree-Snail is apparently known from a single specimen that was collected in the Ereeo valley, where it lived sympatrically with another tree snail species that is now extinct, the Cuneate Tree-Snail (Partula cuneata Crampton.).  

The shell was yellowish corneous and was decorated with irregularly spaced transverse strigations of warm brown. The lip was white and shining. [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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edited: 18.10.2017