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Exploring The Almost Unknown: Land Snail Fauna (Timor-Leste Expedition)

By: Dr Frank Köhler, Michael Hugill, Category: Science, Date: 05 Sep 2012

The humble land snail can be an important environmental indicator. Malacologist Dr Frank Kohler reports on the first ever land snail survey in Timor-Leste, conducted during the Museum's terrestrial expedition.

Timor-Leste Terrestrial Expedition #57

Chris Reid © Australian Museum

Timor-Leste Expedition #5

Why is the Australian Museum in Timor-Leste? To assist with conservation planning and more.

Timor-Leste's land snail fauna is very poorly documented and only a handful of species have been reported until recently. Even if they're not amongst your favourite garden pets, land snails represent a significant proportion of overall biodiversity and are an important element of the food chain in all kinds of natural habitats.

Moreover, because many land snails have quite specific habitat requirements with respect to moisture, soil type, elevation and habitat structure and so forth, they are also considered good environmental indicators. Such indicator species, for example, may tell us about the condition of ecosystems and the effects of disturbances relating to land use or climate change.

What little is known stems from a few studies mainly undertaken during colonial times in the western part of the island of Timor (which today is part of Indonesia). Thus, the Museum's 2012 Timor-Leste Expedition 2012 is also the first ever land snail survey in this country.

In order to find as many different species as possible, the Museum's land snail experts Vince Kessner and I, together with Timorese students, searched for snails in all sorts of habitats throughout the country.

During this survey we found about 100 species of land snails, increasing the number of known species in Timor-Leste by the order of a magnitude. We estimate that perhaps up to 70% of these species may be new to science.

The identification of species requires detailed studies, which entails both morphological and molecular methods; their completion will take probably two years.

Some remarks on the some particularly interesting groups:

  • The family Camaenidae, which is particularly diverse in Australia, is represented in Timor-Leste by two genera that diversified extensively. Tree snails of the genus Amphidromus have conspicuously colourful shells and are represented by an unknown number of cryptic species, which are characterised by highly variable shells. The genus Chloritis encompasses at least thirteen species (ten of them new). In addition, the genus Landouria comprises probably three species.
     
  • Snails of the family Dyakiidae are amongst the largest and most conspicuous snails in Timor-Leste. Species belonging to the genus Asperitas are represented by several differently coloured forms. We are currently studying whether these different colour forms represent different species or not.
     
  • Diplommatinidae is a family that encompasses often minute and narrowly endemic species throughout Southeast Asia. These snails are exclusively found at high altitudes and most of the species found are probably new to science.

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