Natural History, Biogeography and Evolution of Mangrove-Associated Molluscs

David G. Reid

Department of Zoology, Natural History Museum, London SW7 5BD, United Kingdom

Mangrove forests are one of the iconic tropical marine habitats, but are seriously threatened by deforestation and sea-level rise. Both mangrove plants and their associated fauna show maximum global diversity in SE Asia, but this is centred in the South China Sea – not, as in most marine groups, in the Coral Triangle. A few gastropods (e.g. families Potamididae, Batillariidae, Littorinidae) show an obligate association with mangroves for food or habitat, and show remarkable adaptations for life in this challenging environment. A combination of species-level molecular phylogenies, geographical distributions and the fossil record is being used to reconstruct the biogeographic history of these groups. Three processes have contributed to the present distribution and diversity patterns of these molluscs in SE Asia: relictualism, diversification and extinction. All three groups show examples of clades that were once widespread outside the Indo-West Pacific (IWP), but are now restricted to SE Asia and Australasia. The geographical distribution of sister species indicates patterns of both speciation and extinction in the SE Asian hotspot.

Dr David Reid is a Merit Researcher at the Natural History Museum, London. His research interests involve the reconstruction of gastropod phylogenies using both morphological and molecular approaches, and the use of such hypotheses in the study of biogeography and speciation in marine invertebrates, and in the interpretation of the evolution of adaptive morphological characters.