Liew Thor-Seng, MSc

Research interests

Comparative Phylogeography of Animals and Plants on Mount Kinabalu

Mount Kinabalu (4095 m) is the highest mountain in South-East Asia. It stands 1000 m taller than the second highest point in Borneo Islands. Mount Kinabalu holds a tremendous diversity of plants and animals, of which many of them are locally endemics. Despite of this, the ecological and evolutionary processes in this dynamic wide range of habitat are poorly known. At this moment, we are working on ecology of mosses (Genus Dicranoloma and Pogonatum), higher plant (Genus Begonia), beetles (Chrysomelidae: Ivalia) snail (Genus Everettia) and slug (Genus Meghimatium) on Mount Kinabalu. We are also collecting genetic data from these organisms in order to understand their intra- and inter-specific variation along elevational gradient. At the end, we hope to provide a biological evolutionary model for the organisms on Mount Kinabalu; and also predict the response of organisms to current/incoming environmental changes (e.g. climate changes) by understanding the processes that create present-day diversity and distribution patterns.

Revision of Genus Everettia and Genus Meghimatium in Sabah/Borneo

Since Bornean terrestrial malacological inventory research had at its peak in 1890s – 1910s, more information have been accumulated over the past 10 years with the efforts of Menno Schilthuizen and Jaap Jan Vermeulen. More and more new species have been discovered and many of the genera have been revised. However, we have some problems on several groups of land snails, which have only simple conchological setup or high variability in their intra-specific key characters. Among those are land snail Everettia spp. and terrestrial slug Meghimatium spp.

Genus Everettia had been described and revised by Godwin-Austen (1891) and Smith (1895). Until 1920s, at least 16 “Everettia” species were described, mainly from West and North-West Borneo. Since then, little information had been updated and this genus was known as difficult group to work with:

The genus Meghimatium is a wide spread species in East and South East Asia. However, little information of this genus was known from Sabah and Borneo. To date, there were only a few records from this genus in Malaysia (Peninsula Malaysia and Malaysian Borneo). We found an interesting distribution pattern of this genus along the elevational gradient of Mount Kinabalu. Based on the field observation, we noticed that these allopatrically congener species along elevational gradient on Mount Kinabalu have different feeding and ecological behaviour.

We examined the shell morphology (for Everettia), animal body colour, genitalia, genetic and distribution of the specimens in Sabah. In addition to taxonomical revision of the Everettia and Meghimatium, we also try the inference their evolutionary patterns in Northern Borneo and Mount Kinabalu

Island Biogeography of Terrestrial Mollusks in the Tun Sakaran Park (Sabah)

Sabah is known for its heavenly tropical islands. The popular Sipadan Islands is one of them, and there are still plenty of the nice and unexplored islands nearby east coast of Sabah. During the first visit of Menno Schilthuizen to some other adjacent islands around Semporna in 2005, he found a remarkably differences in that land snail compositions between two adjacent islands (of eight islands in Tun Sakaran Marine Park) that least than 50 m apart (and should had been connected during the LGM – 20 kya). In 2007, I was also shocked by the intra-specific variation within species after I examined the snails in all eight Islands.

From our preliminary data, we found that the same species that occur at different island has different shell characteristic. For example, the population of Amphidromus sp. in Bod Gaya Island is 25 % larger in shell size than the population in Bohey Duland Island. There are also some other land snails genera (e.g. Japonia, Leptopoma and Videna) show similar patterns.

However, we are still trying to understand how these variations arise between these adjacent Islands. Is it merely a product of genetic drift or resulted from some underlying ecological adaptation? Why the snails from another study conducted at a few islands on the west coast of Sabah didn’t show the similar trends?