Giant African snail (Lissachatina fulica)

Synonyms: Achatina fulica, Achatina (Lissachatina) fulica

Common Names: giant African land snail, East African land snail, giant East African snail, GALS

Description:

Giant African snail (Lissachatina fulica) is one of the largest and most damaging land snails in the world, native to East Africa and spread around the globe through the pet trade and cargo [1][2]. It is a federally prohibited organism in the United States ? it cannot be legally sold or kept ? and MISIN tracks it because it eats hundreds of kinds of plants, damages buildings, and can carry a parasite that causes a form of meningitis in people [1][2]. It is not established in Michigan, but it has turned up in shipments and luggage, so early detection matters [2].

Identification:

The giant African snail is unmistakably huge. Its pointed, cone-shaped shell can reach about 8 inches (20 cm) long and 4 inches (10 cm) across ? roughly the size of an adult fist ? with seven to nine whorls [1]. The shell is brownish with dark brown vertical stripes over at least the lower half, fading to nearly white near the pointed tip [1]. No native North American land snail comes close to this size, so a snail this large is a red flag [1][2].

These snails are most active at night and in damp, warm weather, when they feed on plants and may climb walls and buildings [1]. Look for the snails themselves, large ragged holes chewed in plants, and scraped or eaten patches of paint and stucco on houses, where the snails rasp at surfaces to get calcium for their shells [1][3]. Do not handle one bare-handed ? see Management [1].

At-a-glance cues:

1. Very large pointed, cone-shaped shell up to about 8 inches (20 cm) long ? fist-sized or bigger, far larger than any native snail [1]
2. Brownish shell with dark brown vertical stripes, fading to near-white at the tip, with 7?9 whorls [1]
3. Large ragged holes chewed in many kinds of plants [1]
4. Scraped or eaten paint and stucco on buildings, where snails get calcium [1][3]

Habitat:

The giant African snail does best in warm, humid, tropical and subtropical places, and in the United States the main concern is warmer regions with plenty of crops and gardens [3]. It shelters by day under plants, debris, and structures and comes out to feed at night and after rain [1]. It is a generalist that is not tied to any one habitat, turning up in gardens, farms, nurseries, and around buildings [1][2].

The snail is native to East Africa [2]. It has been carried far beyond its home range through the pet trade and in cargo, and is now established in parts of Asia, the Pacific, the Caribbean, and South America [1][2]. In the continental United States it has repeatedly invaded Florida and been the target of eradication, but it is not established in Michigan [2]. It feeds on an enormous range of hosts ? more than 500 kinds of plants, including many crops and ornamentals [1][2].

Reproduction:

The giant African snail spreads almost entirely because people move it. It is carried on purpose as an illegal pet or for classroom use, and it travels by accident in cargo, in the soil of potted plants, and in luggage ? snails from this species have been intercepted in travelers' bags arriving in the United States [1][2]. Because it is a federally prohibited organism, keeping, selling, or moving it is illegal, and even one snail can be a serious problem [1][2].

This snail is a hermaphrodite ? each one has both male and female parts ? and it can fertilize itself, so a single snail can start a whole new population [2]. It breeds fast: snails begin laying eggs at about six months old and lay clutches every couple of months, on the order of a hundred eggs in the first year and several hundred a year after that, adding up to as many as a thousand eggs over a life of up to about five years [3]. This explosive output is why finding and reporting even one snail early is so important (see Management) [1].

Impact and Damage:

The giant African snail is a rare invader that threatens people, property, and farms at once. The most serious concern is human health: the snail can carry the rat lungworm (Angiostrongylus cantonensis), a parasite that can infect people who handle infected snails or eat contaminated produce and cause a form of meningitis (eosinophilic meningitis) [1][2]. For this reason the snails should never be handled with bare hands [1].

It is also a major pest of plants and buildings. It feeds on more than 500 kinds of plants ? including many crops and garden plants ? and it rasps at plaster, stucco, and paint to get calcium for its shell, damaging houses and other structures [1][2]. Because dense populations can build quickly and the snail is so hard to remove once established, it is treated as a top-priority invader: the United States has carried out costly eradication programs in Florida, removing well over 150,000 snails in a single campaign [2]. Its effects on native snails and natural areas add to the concern [1].

Similar species:

Nothing native to the region reaches the giant African snail's size, but a few snails are worth comparing.

Other giant African land snails (Achatina and Archachatina spp.) are close relatives sometimes seen in the illegal pet trade and are also federally prohibited; they are similarly huge and best separated by an expert from shell shape and the color inside the opening.

Rosy wolfsnail (Euglandina rosea) is a large snail of the southeastern United States, but it is much smaller (about 3 inches), with a narrow spindle-shaped pinkish-brown shell rather than the giant African snail's massive striped cone.

Brown garden snail (Cornu aspersum) is a common garden snail, but it is far smaller (about an inch) with a rounded, wrinkled brown shell, nothing like the giant African snail's fist-sized pointed shell.

Monitoring and rapid response:

Signs to watch for:

1. Very large, fist-sized or bigger snails with a pointed, brown, dark-striped shell ? far larger than any native snail [1]
2. Large ragged holes chewed in many kinds of plants, especially after warm, damp nights [1]
3. Scraped or eaten paint and stucco on buildings where snails get calcium [1][3]

What you can do:

1. Do not touch a suspected giant African snail with bare hands ? it can carry a parasite (rat lungworm) that infects people; if you must move one, wear gloves and wash your hands well afterward [1][2].
2. Do not keep, sell, trade, or move these snails ? they are federally prohibited, and even one self-fertilizing snail can start a population [1][2].
3. Photograph the snail next to a coin or ruler for scale, note the exact location, and report it right away (below) ? this is a top-priority invader and rapid reporting drives eradication [1][2].
4. If safe to do so, contain the snail (for example under a bucket) so officials can collect it; do not release it [1].
5. Natural area crews and land managers should treat any suspected find as a regulatory matter and coordinate with USDA APHIS and the state agriculture program, which run surveys, canine and visual detection, and hand removal under an official eradication program [1][2].

When to call a professional:

1. Any suspected giant African snail ? report it immediately to USDA APHIS or your state agriculture department, since this species is federally actionable and targeted for eradication [1][2].
2. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. USDA Animal and Plant Health Inspection Service (APHIS). Giant African Snail (Lissachatina fulica) ? Mollusks / Plant Pests & Diseases. aphis.usda.gov
2. USDA National Invasive Species Information Center. Giant African Snail (Lissachatina fulica). invasivespeciesinfo.gov
3. Michigan Department of Natural Resources, Invasive Species Program. Giant African Snail (Lissachatina fulica). michigan.gov/invasives

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