Giant African Snail

• It is on the IUCN list of the 100 most damaging invasive alien species in the world.
• It is hermaphroditic: two individuals fertilise each other and both lay eggs, and a single pair can produce hundreds of offspring in a year.
• It can transmit the nematode Angiostrongylus cantonensis, which causes eosinophilic meningitis in humans, so it should not be handled without washing your hands afterwards.
• In the dry season it seals the shell opening with a sheet of hardened mucus and goes dormant.
• It appears on the IUCN list of the hundred worst invasive species in the world.
• It eats almost anything: it prefers decomposing vegetation, lichens and fungi, but it has been recorded on hundreds of plant species, and masses of snails can raze an entire seedbed in a single night.
• Its health risk is the most serious part: it is an intermediate host of the nematode Angiostrongylus cantonensis, the rat lungworm, which causes eosinophilic meningitis in people. Infection comes from eating raw or undercooked snails, or vegetables contaminated with their slime.
• It was almost always introduced on purpose: as food, as a pet, for educational purposes or for rearing. It is a textbook case of invasion by the deliberate route.
• Its size helps explain the problem: its shell reaches 20 cm and it lays several hundred eggs per clutch, with several clutches a year.
• It is a hermaphrodite, and a single individual is enough to found a population if it has already been fertilised.
• Florida managed to eradicate it twice, most recently with the lifting of the quarantine in 2021 after years of campaigning; it is one of the few successful eradications of an invasive mollusc.

Skeleton type

Invertebrate - external calcareous shell (mollusc)

Habitat and environment

Humid tropical areas: crops, gardens and forest edges

Sexual maturity

5-8 months

Gestation / incubation

11-15 days

Litter / clutch size

100-400 eggs per clutch, with several clutches a year

Life expectancy in captivity

Up to 9 years

Sources consulted: https://es.wikipedia.org/wiki/Lissachatina_fulica