Partula hyalina

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Partula hyalina
Naturalis Biodiversity Center - ZMA.MOLL.384965 - Partula (Partula) hyalina Broderip, 1832 - Partulidae - Mollusc shell.jpeg

Partula hyalina

Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Partuloidea
Family : Partulidae
Genre : Partula
Type : Partula hyalina
Scientific name
Partula hyalina
Broderip , 1832

Partula hyalina is a species of snail in the genus Partula . It is the only Partula species in French Polynesia to be native to several islands - Tahiti , the Austral Islands and the Cook Islands . Since no invasive predatory slugs have been introducedon some of these islands, it is the only species of the Partulidae familythat still has some stable populations.

description

The elongated, whitish translucent snail shell of Partula hyalina reaches a length of about 23 mm and a diameter of 8 mm with 6 whorls. The case mouth is 9 mm long and 3 mm wide. The surface shows slight vertical stripes and numerous weak transverse lines. The lip of the case mouth is white. The hermaphroditic snail gives birth to living young. It feeds on microscopic plants and detritus.

Spread and endangerment

Partula hyalina can be found on seven islands of French Polynesia and the Cook Islands : from the Society Islands only on Tahiti , from the Austral Islands on Rurutu , Tubuai , Raivavae and Rimatara , from the Southern Cook Islands on Mangaia and Mauke . Like other tree snails, it lives on deciduous trees.

On the basis of molecular genetic studies by Lee et al. a. (2007) it is assumed that the species was initially only native to Tahiti and was brought to four of the Austral Islands and two of the Cook Islands by Polynesian traders . Until the 20th century, the shells of the Partula snails, which were previously common in the region, served as an important material for jewelry , so that humans were a direct enemy, but also a factor in the spread of these snails. Partula hyalina is closely related to Partula clara , which is also native to Tahiti and which is possibly just a variety of Partula hyalina .

Like other Partula species, the population of Partula hyalina was severely decimated by the rosy wolf snail ( Euglandina rosea ), which was introduced into French Polynesia from 1974 to combat imported large agate snails . While other Partula species have completely disappeared, colonies of Partula hyalina were found in 2007 in about a third of the valleys of Tahiti and on the island of Tubuai , although the rosy wolf snail has established itself there. This gives reason to hope that Partula hyalina can survive even in the presence of the predator, albeit with a significantly lower population density. There are no rosy wolf snails on the other five islands in their range, so there are intact populations of Partula hyalina there. The introduction of said predatory snails or other carnivorous invasive species to these islands is seen as the greatest danger . The ant species Wasmannia auropunctata is also one of the predators of Tahiti .

literature


Individual evidence

  1. ↑ William John Broderip (1832): Characters and descriptions of new species of Mollusca and Conchifera collected by Mr. Cuming . Proceedings of the Committee of Science and Correspondence of the Zoological Society of London 2, pp. 25-33. P. 32 . Genus Partula. Partula hyalina. Part. Testâ oblongâ, hyalinâ, anfractibus sex, longitudinaliter levissimè striatis et transversim minutissimè creberrimèque lineatis; labro albo: long: long. 9/10, lat. 3/10 poll. [= inch] Habitat in Polynesiâ. (Oheataroa.) The sculpture of this elegant species is most minutely delicate. - WJB