Giant East Africa Snail
Synonym(s): Lissachatina fulica
Photographer: R. Zimmerman USDA-APHIS
The giant African snail can most readily be recognized by its large size with shells at least 2 inches in length and averaging the size of an adult human fist when the snails are mature. Giant African snails that are found in the United States can be one of three species: giant African snail (Achatina fulica), giant Ghana tiger snail (Achatina achatina), and margies (Archachatina marginata). All three species of snails are terrestrial and can reach up to 8 inches in length and 4 inches in diameter. The shells of the snail are darker colored with stripped markings covering half of the shell or more.
Ecological Threat: Giant African snails are highly capable of becoming agricultural threats due to their large size and foraging behavior. As hearty and aggressive mollusks, giant African snails pose the largest threat to damaging food crops grown all over the United States. With enormous appetites the giant African snail is known to eat over 500 species of plants when fruits and vegetables aren't available. When adequate vegetation isn't available in the form of fruits or vegetables the giant African snail will consume ornamental plants, tree bark, or stucco on houses. They also pose a health risk for humans and should not be consumed as food or handled. Snails from this family are known carriers of the parasite (Angiostrongylus cantonensis) which transmits eosinophilic meningitis. However, no infected snails have been confirmed in the United States. Giant African snails become infected with this parasite by consuming infected rat feces. The risk of transmitting this disease in the United States is low, but the possibility is still present.
To learn more about Angiostrongylus cantonensis click here
Biology: Like most snails, the giant African snail contains both male and female parts on one individual (hermaphroditic). This allows for rapid breeding potential of 100 to 400 eggs laid per season with up to 1,200 eggs laid in one year due to the high reproductive potentials of the male and female organs.
History: In 1966, three giant African snails were introduced to Florida (illegally) as pets in a home in Miami. The snails were released into the garden without knowledge of their damage potential. Within a short time of 7 years, 18,000 giant African snails were present in Florida costing the state $1 million in efforts to eradicate the species. The giant African snail has been declared illegal to sell and own as a pet in the United States due to the risks associated with the animal. Confiscations have been made in Ohio, Wisconsin, and Illinois from pet stores that were illegally selling the giant snails as pets. Other snails have been confiscated from schools due to teachers using them as teaching tools without being aware of the potential dangers and illegality of owning the animal.
U.S. Habitat: Giant African snails can be found in areas that are moist and contain adequate vegetation for food consumption. Like most snails, the giant African snail can be found in gardens or fields of cultivated crops where water is regularly supplied. The giant African snail is terrestrial in all three species that can be found in the United States, but it prefers moist areas. Native to warm and tropical climates, the giant African snail thrives where it is warm, however it is capable of surviving in colder northern states by hibernating through the winter months.
Native Origin: East Africa
U.S. Present: Hawaii and Florida; with possible sightings in Texas (yet to be confirmed).
Local wildlife authorities are working to enforce prevention and early detection as the primary method of managing the giant African snail. It is important to notify local wildlife authorities if you find a snail that has a shell that is 2 inches or larger. Native snails are never larger than 2 inches in length and will be obviously smaller than the invasive giant African snail. It is important to remove any snails that have been released and prevent further release of the the giant African snail so it does not become established in new areas.
Bequaert, J. C. (1950). Studies in the Achatininae, a group of African land snails. Bulletin of the Museum of Comparative Zoology at Harvard College 105(1): 1-216.
Raut, S. K., and G. M. Barker. (2002). Achatina fullica Bowdich and other Achatinidae as pests in tropical agriculture. In: Barker, G. M. (ed.) Molluscs as Crop Pests, CAB International 2002, pp. 55-114.