Land Snail Research
To study land snail endemism in Malaysia and Singapore
Limestone in the humid tropics is subject to severe weathering because of high rainfall, humidity, and biological productivity. This may result in spectacular morphologies such as blocks of limestone with steep cliffs and riddled with caves and sinkholes. In Peninsular Malaysia and Borneo, numerous more or less isolated karst outcrops of this type are widely scattered over the landscape. Since the late 19th century it is known that Malaysian limestone hills hold a very high diversity of – often endemic – landsnails (Stylommatophora).it has recently been estimated that a patch of limestone habitat can support two to five times more species than a similar patch of non-limestone habitat, and that the number of shells found there is 10-1000 times as high. Limestone hills represent less than 1% of land but support probably around 80% of all terrestrial molluscs of Malaysia!
Because limestone karst ecosystems contain high numbers of endemic and threatened taxa, they qualify for inclusion into reserves. Karst biodiversity, such as landsnails, exhibits relatively high endemism, but various activities, primarily mining and construction, but also tsunamis, trampling by livestock etc., threaten their survivorship and in some cases have caused extinctions.
In this project, a critical issue concerning unsampled localities facing extirpation is addressed: can their levels of endemism be predicted, and can those that warrant conservation be singled out?
Datasets of 17 environmental variables and species occurrences (historical and modern) of snails endemic to Peninsular Malaysia, Sabah, Sarawak and Thailand, are being fitted into statistical models in conjunction with a geographical information system (GIS) to predict landsnail endemism at unsampled karsts. The project addresses a wide range of species belonging to no less than 41 genera: Achatina, Dyakia, Hemiplecta, Macrochlamys, Microcystina, Pseudoplecta, Quantula, Amphidromus, Chloritis, Phaedusa, Alycaeus, Chamalycaeus, Cyclophorus, Geotrochus, Lagochilus, Opisthostoma, Platyraphe, Pterocyclus, Rhiostoma, Diplommatina, Philalanka, Ena, Coneuplecta, Liardetia, Queridomus, Helicarion, Georissa, Pupina, Discartemon, Gullela, Sinoennea, Cecilioides, Lamellaxis, Paropeas, Sublina, Videna, Vitrinopsis, Pupisoma, Gyliotrachela, Hypselostoma, Paraboysidia.
WAZA Conservation Project 06011 is supported by Singapore Zoological Gardens through its Wildlife Research and Conservation Fund, and the National University of Singapore.
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