Partula gibba
| Partula gibba | ||||||||||||
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Partula gibba |
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| Scientific name | ||||||||||||
| Partula gibba | ||||||||||||
| Férussac , 1821 |
Partula gibba is an endangered species of snail in the genus Partula that is found in the Mariana Islands, including Guam .
description
The right- or left-wound, conical egg-shaped, thin-walled snail shell of Partula gibba reaches a length of 14 to 18 mm and a width of 10 to 14 mm. The thread is pointed and consists of four to four and a half whorls, with the body circumference protruding. The shell is provided with spiral stripes and weak growth stripes. The white or brown seam is lightly pressed. The case mouth is elongated, egg-shaped, approximately square with a bent, widened, white case edge. The edge of the spindle is somewhat widened above, over the navel. The color of the housing surface is very variable from chestnut brown to whitish yellow or even purple. The hermaphroditic snail gives birth to living young. It feeds on microscopic plants and detritus.
Spread and endangerment
Partula gibba is native to nine islands of the Mariana Islands : Guam , Rota , Aguiguan , Tinian , Saipan , Anatahan , Sarigan , Alamagan and Pagan . Like other tree snails, it can be found on deciduous trees.
In investigations since the 1990s, Partula gibba was no longer found in various locations on the islands of Guam, Saipan, Rota, Tinian and Aguiguan, where it was still common in 1920 and 1949, respectively. The reason for the decline is the destruction of the habitat by animal husbandry and the like. a. with goats as well as the introduction of predatory snails and flatworms . To combat large agate snails introduced on Guam, the rosy wolf snail ( Euglandina rosea ) was introduced in 1957 and the land planarie Platydemus manokwari in 1978 , whereupon the populations of agate snails and also the native snail species declined sharply. In contrast to many other Partula species, colonies of Partula gibba are still being found on Guam, among others, but their existence cannot be guaranteed without protective measures.
literature
- Barry D. Smith, Ramsay Cooper-Nurse, and Ann Marie Gawel (2015): Survey of Endangered Tree Snails on Navy-Owned Land in Guam . PDF
- David R. Hopper, Barry D. Smith (1992): Status of tree snails (Gastropoda: Partulidae) on Guam, with a resurvey of sites studied by HE Crampton in 1920 . Pacific Science 46, pp. 77-85. PDF
