Partula citrina Pease

Light Yellow Tree-Snail (Partula citrina)

This species was described in the year 1866.

The Light Yellow Tree-Snail occurred only in the Uparu valley on the west coast of the island of Ra’iatea.

The shell reached a height of about 2,3 cm.

Advertisements

Justin Gerlach: Partula – Icons of Evolution

Justin Gerlach: Partula – Icons of Evolution

The genus Partula, extremely rich in Polynesian species, will soon get it’s newest monograph (I’m not sure, but it may be the first monograph at all).

The book, written by Justin Gerlach and named “Partula – Icons of Evolution”, is nearly ready to be published, but the project can still be supported.:

https://www.kickstarter.com/projects/507116283/partula-icons-of-evolution

 

Partula otaheitana (Bruguière)

Otaheite Tree Snail (Partula otaheitana)

The Otaheite Tree-Snail, whose name refers to it as being endemic to the island of Tahiti (Otaheite is an old name of the island), was described in 1792.

This species is nowadays highly threatened with extinction, yet somehow managed to withstand the introduction of the Rosy Wolf Snail (Euglandia rosea (Férussac)) to Polynesia, that had cost the lives of so many other endemic snail species.

~~~

The Otaheite Tree-Snail is split into four so called anatomical forms, which overlap or are linked to each other by intermediate forms, and which are each restricted to certain parts of Tahiti. They may or may not be treated as subspecies, and are named as Partula otaheitana ssp. crassa Garrett (in the western part of Tahiti nui), Partula otaheitana ssp. otaheitana Bruguière (in the northern part of Tahiti nui), Partula otaheitana ssp. rubescens Reeve (in the eastern part of Tahiti nui as well the northern part of Tahiti iti), and finally Partula otaheitana ssp. sinistrorsa Garrett (in the largest part of Tahiti nui, including the center of the island and the southern part, as well as the most parts of Tahiti iti).

*********************

References:

[1] Justin Gerlach: Icons of Evolution: Pacific Island tree-snails, family Partulida, Phelsuma Press, Cambridge U.K. 2016

********************

Photo: Antonio Machado; by courtesy of Antonio Machado

********************

edited: 31.08.2017

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]

~~~

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]

*********************

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

*********************

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

(public domain)

*********************

edited: 31.08.2017

Partula fusca Pease

Brown Tree-Snail (Partula fusca)

The Brown Tree-Snail, whose shells were not always brown colored, but were as variable as the shells of most tree-snails, was endemic to the island of Ra’iatea.

The species was obviously not a tree dweller but terrestrial.

The Brown Tree-Snail, like most of its relatives from the island of Ra’iatea, died out at the end of the 20th century.

*********************

partula-fusca-mc

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

http://www.biodiversitylibrary.org

Partula auriculata Broderip

Ear-shaped Tree-Snail (Partula auriculata)

This species was decsribed in the year 1832.

The Ear-shaped Tree-Snail was an endemic species of the island of Ra’iatea and disappeared shortly after the introduction of the Rosy Wolfsnail (Euglandina rosea (Férussac)) to the island. In the year 1992, when the species was seen for the last time, only a few individuals were left.

The species was not found during field surveys in the years 1994 and 2000, nor during any other subsequent survey, and therefore is considered extinct now.

*********************

partula-auriculata-mc

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

http://www.biodiversitylibrary.org

Partula cuneata Crampton

Wedge-shaped Tree-Snail (Partula cuneata)

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

The species was endemic to the island of Ra’iatea, where it was restricted to the Ereeo Valley on the west coast of the island, which it shared with five additional tree-snail species – all of these species are now extinct.

*********************

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

Partula rustica Pease

Rustic Tree-Snail (Partula rustica)

This species comes from the island of Ra’iatea, and was obviously restricted to a single valley at the west coast of the island, where the animals were found under decaying plant material.

The Rustic Raiatea Tree-Snail is now, like most of its relatives from the island of Ra’iatea, considered extirpated.

*********************

partula-rustica-mc

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

http://www.biodiversitylibrary.org

Partula callifera Pfeiffer

Callus-carrying Tree-Snail (Partula callifera)

This species was described in the year 1856.

The Callus-carrying Tree-Snail occurred in the higher parts of the Haamoa valley in the east of the island of Ra’iatea, where it formerly was found quite commonly, sitting on the foliage of the native vegetation.

The shells reached a heigth of 1,7 to 2,1 cm.

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