Introduced Species Summary Project
Giant (East) African Snail (Achatina fulica)

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Figure 1 – Achatina fulica Thailand

Common Name:  Giant (East) African Snail (giant African land snail, escargot Geant, Achatine, Caramujo)

Scientific Name:  Achatina fulica


Phylum or Division:   Mollusca
Order:  Pulmonata                                                                                                                                                      Suborder:  Sigmurethra                                                                                                                                             Infraorder:  Holopodopes

Identification:   Full grown Achatina fulica reach up to 20 cm in length and 12 cm in maximum diameter.  The dark and light brown (sometimes more of a cream color) swirls wrap around its cone like shell.   Its convex body allows for about 7 to 9 whorls.  The outlines of the whorls fluctuate from narrow to broad even within the same colony.  An adult Achatina Fulica’s lip opening is generally very thin and sharp.  The shell itself is thick and strong if healthy (needs a high calcium diet).  The rest of the body resembles a slug like appearance with a variance in color. 


        Figure 2 – Anatomy of an achatinid snail                                                                                                                       

Original Distribution:  Achatina fulica originates from coastal East Africa particularly Kenya and Tanzania.  First sightings occurred before the 1800’s.

Current Distribution:  Giant African Snails can be found in most southern hemisphere countries, eg. throughout Africa, Indian Ocean Islands, Australia, New Zealand, South America.  In addition, these snails have been identified in Southern, Southeastern and Eastern Asia, Polynesia and other Pacific Islands, West Indies and the United States.  Typically, Giant African Snails have been found along the coastline and in southern states of the USA.  However, sightings have also occurred in Wisconsin, Michigan and Ohio.  These snails thrive in humid, tropical climates. 

Site and Date of Introduction:  As indicated in the map below, introduction of Giant African Snails dates back to the early 1800’s.  These snails spread throughout East Africa into Ethiopa, Somalia, Mozambique, and Madagasar.  Interestingly, they were not sighted in northern Africa until the late 1980’s.  

The first occurrence of these snails outside of Africa was Bengal, India in 1847.  Since then, the Giant African Snail has been transported mistakenly and purposefully throughout the countries listed in the above section. 

Giant African Snails were first spotted in the US in the late 1940’s around San Pedro, California.  Many of these snails were affixed to cargo imported to the US.  Over 50 interceptions occurred within a ten year span (from 1948-1958) in the California ports.

In 1958, a young boy stashed Giant African Snails into his suitcase from his travels in Hawaii returning to California and driving to Arizona.  Once the snails were discovered in his belongings, they family released them to the outdoors.  Another very similar incident occurred in 1966, where another young boy visiting Hawaii decided to take a few Giant African Snails home to Miami, Florida to keep as pets and were released into the family’s garden.  The Florida State eradication process took 10 years costing over one million dollars.

These snails continue to enter the US through illegal trade or in shipping containers and in plant shipments from the Hawaiian Islands, Guam and other Pacific Islands.  Inspectors fairly easily identify these snails, intercept them and eradicate them.

In the early 2000’s the introduction of Giant African Snails have also occurred in Wisconsin, Michigan and Ohio due to pet store trade and educational institutions’ requests. 

Figure 3 - Dissemination of achatinid snails from Africa since 1804

Mode(s) of Introduction:   As mentioned above, Giant African Snails are intercepted most often in the California ports from shipments containing goods and plants from Hawaii, Guam and the Pacific Islands.  Other modes of introduction are through illegal trade to pet stores and to educational institutions.  One assumes that those making the requests for these snails are not aware of the hazardous lethal health effects to humans.  Generally once sold or used in the classroom, the snails are released to the outdoors.

            If these snails are not immediately intercepted, they populate exponentially making it extremely difficult to control in a timely and cost efficient fashion. 

Reason(s) Why it has Become Established:   Achatina fulica begin laying eggs at 5 to 6 months.  Each snail can produce from 10 to more than 400 eggs, 8 to 20 days after mating.  If optimal conditions exist, a single snail can produce from 300 to 1000 eggs in 3 to 4 batches per year.  In tropical (humid) conditions, eggs can hatch after 11 days.  Giant African Snails’ lifespan lasts about 3 to 5 years, however some may live as long as 9 years. 

Even though Achatina fulica prefer and thrive in more humid and warm conditions, they are highly adaptable to dry and cooler climates.  They hibernate 10 to 15 cm deep in soft soil during less favorable conditions for up to one year.  Their herbivore diet includes over 500 different plant species, including breadfruit, cocoa, papaya, peanut, rubber, and most types of beans, peas, cucumbers and melons.  In addition, they forage on animal matter, lichens, algae and fungi. 

The Achatina fulica produces a heavy slimy substance allowing for smooth and easy travel across rough and sharp surfaces.  They can slide over a razor blade without being injured.

Ecological Role:  Achatina fulica forage on over 500 different plant species.  During less favorable conditions (dry, cool), they nest in lose soil for during their period of hibernation.  One may postulate that this behavior promotes health in the soil as the soil is churned and as matter from the snail settles into the soil.  However, with over population, the snails destroy and pollute their surroundings, including the soil.

Benefit(s):  Giant African Snails contribute to the degradation of animal matter.  In addition, the Giant African Snail provides nutrients to the India glowworm Beetle; specifically to the larvae (male larvae consume 20 to 40 Achatinas; female larvae eat 40 to 60 Achatinas during their development).  Other beetle species consume the Achatina fulica, such as the lampyriad and the coprine beetle. 

The hermit crab is one of the most dangerous predators to the Achatina fulica and has been known to use the shell as its home.  The coconut crab also views the Achatina fulica as a delicacy.  The domesticated duck along with a vast variety of other bird species forage on Giant African Snails.  Other mammals such as the wild pig prey on Achatina fulica.

Threat(s):    The Giant African Snails’ greatest lethal threat to humans is eosinophilic meningitis.  This condition is caused by the rat lungworm parasite, angiostrongylus cantonesnsis.  Most often this parasite is transferred by eating the snail, as some humans consider snails a delicacy.  In addition the Giant African Snail can carry the gram-negative bacterium, aeromonas hydrophila, causing a wide variety of symptoms, especially in persons with a weak immune system. 

Giant African Snails cause great economic peril to farmers due to their propensity in consuming large amounts of crops/plants.  Their diet consists of over 500 different plant species.  A wide variety of horticulture and medicinal plants are known to be attacked by this snail.  Not only does this decrease the income for agricultural producers, but it also impacts their living conditions (often requiring relocation) and decreases food and medical resources for humans, animals and other species. 

The economic consequences persist in eradicating these creatures, sometimes costing millions of dollars.  Another economic penalty involves the decrease in tourism.  As noted earlier, Giant African Snails thrive in warm, tropical conditions – often tourist destinations.

Giant African Land Snail

Figure 4 – Giant African Snail invading plant site

Control Level Diagnosis:  The Giant African Snail is considered one of the most land damaging snails in the world. 

The most significant time period for the Giant African Snail to cause destruction to a given area is when it is first established.  Their ability to reproduce exponentially with in their first 5 to 6 month of life offers little time to respond to such infestation.  Therefore, the Giant African Snail is designated as “high priority” for the need to be controlled/eradicated immediately after the first sighting in a given area.   

Control Method:  Molluscicides have been designated as one of the most effective means to eradicate the Giant African Snail.  The most widely used active ingredient is the metaldehyde.  The downside is that most molluscicides negatively impact the soil, plants and other beneficial organisms (such as ground beetles and earthworms). 

Iron phosphate is becoming more popular in use for killing snails with less negative consequences to other beneficial organisms.

Education provides great opportunity to decrease and eventually stop the illegal trading and importation of the Achatina fulica.  Educational institutions would prohibit such introductions of this snail if the lethal consequences were known.  The same would be true for pet trade stores selling these creatures as pets.

The above measures are the most effective in controlling across large areas of land.  Other methods, such as creating frigid temperatures or saturating the snails in ethanol, are also effective in controlling the Giant African Snail.


Biosecurity New Zealand: ;                            

ITIS Report:

New Pest Response Guidelines: Giant African Snails: Snail Pests in the Family Achatinidae:

The Animal and Plant Health Inspection Service: ;

The Giant African Snail: A problem in Economic Malacology.  Chapter 7.  Biological Control. :

United States Department of Agriculture:  National Agricultural Library:



Figure 1:  Achatina fulica Thailand:

Figure 2:  New Pest Response Guidelines: Giant African Snails: Snail Pests in the Family Achatinidae. Pg. 26.

Figure 3:  New Pest Response Guidelines: Giant African Snails: Snail Pests in the Family Achatinidae. Pg. 16

Figure 4:  Oregon State University:

Author: Heather Stokes
Last Edited: November 12, 2006

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