South American apple snails, Pomacea spp. (Ampullariidae), in Singapore T.H. Ng1, S.K. Tan2 and D.C.J. Yeo1 1Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Singapore 117543. Email:
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[email protected] 2Lee Kong Chian Natural History Museum, National University of Singapore, 2 Conservatory Drive, Singapore 117377 Abstract South American apple snails, Pomacea spp. (Ampullariidae) have been established in Singapore since the late 1980s. Based on molecular analyses and shell morphology, two species of Pomacea (P. canaliculata and P. maculata) have been found. The introduction of Pomacea to Singapore was probably accidental via the aquarium trade. Their current status and distribution in Singapore are summarised herein. In highly urbanised Singapore, the species have not caused obvious environmental damage, in contrast to the agricultural damage they have caused in rice plantations throughout neighbouring Southeast Asian countries. Nevertheless, the introduced Pomacea are now widespread throughout the island city-state, and may be competing with the native Southeast Asian ampullariid, Pila scutata, which has declined since the arrival of Pomacea. Other potential impacts of Pomacea spp. in Singapore include modification of wetland habitat and acting as vectors of human disease. Some measures to remove Pomacea in localised areas have been initiated. However, eradication of these introduced apple snails appears difficult, if not impossible. Additional keywords: introduced, invasive, gastropod, freshwater, Mollusca 221 Introduction There are some 25 species of freshwater gastropods in the island city-state of Singapore, the largest of which are species of the family Ampullariidae (Tan & Woo, 2010; Tan et al., 2012).