The Applesnail Pomacea canaliculata originally lives in South-America,where it lives in Southern Brazil and Argentina.It is a large freshwatersnail,with a shellsize of up to 10 cm.The shell is brownish or greenish with some spiral banding,the body of the animal can be dark to cream colored. Like all Applesnails the sexes are separate. The habitat of this snail are swamps,ponds and lakes where it hides during the day and comes out at night to feed on fresh vegetation. It was imported in the 1980's to Southeast Asia as a foodsource.Unfortunatly the enter- prise never became a success.Export to Europe failed because of the risk of a dangerous parasite being present in the snail. Snails which escaped from commercial breeding farms quickly spread throughout Southeast, South and East-Asia.Probably from The Phillipines it got introduced in Hawaii,again as a foodsource.It has also made its way into Texas and California.Australia is very worried about the impact of the snail on its natural wetlands and agricultural fields. The impact of the snail on infested areas has different aspects.First there is the damage to the crops,also the broken shells cause injuries to workers feet. Farmers used and use a lot of different chemicals to get rid of the snail.This kills other native wildlife as well. Besides this Pomacea is posing a threat to native freshwatersnails for example Pila species in South-East Asia.The voracious eating habits are also causing problems in natural wetlands when native plants get eaten.
It is very difficult to get rid of Pomacea canaliculata once it is established in a ricefield or wetland area.Chemicals are harmful to both humans and other animals. The best method is probably handpicking,when its done on a regular basis.Also removing egglaying opportunities around fields like vegetation can hold back further spreading.
More info: Fact sheet for Pomacea canaliculata Invasive species database The South East Asian snail disaster