Abstract
P. canaliculata is a freshwater snail native to parts of Argentina and Uruguay. The distribution of P. canaliculata has been steadily increasing since its introduction to Asia, primarily as a human food resource but perhaps also by the aquarium trade, beginning around 1979 or 1980 (Mochida, 1991; Halwart, 1994a; Cowie, 2002; Joshi and Sebastian, 2006). Once introduced to an area, it spreads rapidly through bodies of water such as canals and rivers and during floods. It feeds on aquatic plants and can devastate rice (in South-east Asia), taro (in Hawaii) and other aquatic or semi-aquatic crops. It may out-compete native apple snails (Halwart, 1994a; Warren, 1997), prey on native fauna (Wood et al., 2005, 2006) and alter natural ecosystem function (Carlsson et al. 2004a). It is also an important vector of various parasites including the nematode Angiostrongyulus cantonensis, which causes human eosinophillic meningitis (Lv et al., 2011; Yang et al., 2013).It is listed among '100 of the world's worst invasive species' (Lowe et al., 2000). In the United States its transport between states is restricted (Gaston, 2006), as is its transport between islands in the Hawaiian archipelago (Tamaru et al., 2006). It is listed as a quarantine pest in Malaysia (Yahaya et al., 2006) and in Japan. Australia has strong quarantine restrictions and is particularly concerned about P. canaliculata (Cowie, 2005).