Archachatina marginata

File:African Giant Snail.jpg

This species occurs in Western Africa (Cameroon to the Democratic Republic of the Congo) and the Caribbean (Martinique).{{Cite web|url = https://www.aphis.usda.gov/plant_health/plant_pest_info/gas/downloads/achatinamarginata.pdf|title = Archachatina marginata (Swainson, 1821)|access-date = October 29, 2015|website = United States Department of Agriculture|publisher = USDA/APHIS|archive-date = July 22, 2021|archive-url = https://web.archive.org/web/20210722002632/https://www.aphis.usda.gov/plant_health/plant_pest_info/gas/downloads/achatinamarginata.pdf|url-status = dead}} How the species reached Martinique is unknown, but they may have been intentionally introduced as "pets" or by workers returning from West Africa.{{Cite web|url = http://freshfromflorida.s3.amazonaws.com/The-Giant-African-Snail-Lissachatina-fulica-History-and-Reported-Biology_Robinson.pdf|title = The Giant African snail (Lissachatina fulica); its history and reported biology|access-date = October 29, 2015|publisher = USDA APHIS National Malacology Laboratory and The Academy of Natural Sciences|last = Robinson|first = David G.|archive-date = March 4, 2016|archive-url = https://web.archive.org/web/20160304064639/http://freshfromflorida.s3.amazonaws.com/The-Giant-African-Snail-Lissachatina-fulica-History-and-Reported-Biology_Robinson.pdf|url-status = dead}}

The natural spread of this species is very slow; however, unintentional spread by individuals for food and as folk medicine is very common.[https://www.sciencedaily.com/releases/2009/11/091119101207.htm Let Them Eat Snail: Nutritional Giant Snails Could Address Malnutrition]. ScienceDaily (November 20, 2009) The USDA routinely checks for the species in the luggage of travelers from West Africa, Nigeria particularly, Ghana, and Cameroon.

This species has not yet become established in the United States, but it is considered to represent a potentially serious threat as a pest, an invasive species that could negatively affect agriculture, natural ecosystems, human health, or commerce. Therefore, this species may be given top national quarantine significance in the United States.{{cite journal|author=Cowie R. H., Dillon R. T., Robinson D. G. & Smith J. W. |year=2009|title=Alien non-marine snails and slugs of priority quarantine importance in the United States: A preliminary risk assessment|journal=American Malacological Bulletin|volume=27|issue=1–2 |pages=113–132|doi=10.4003/006.027.0210 |s2cid=54919881 |url=http://dillonr.people.cofc.edu/Cowie-et-al-2009.pdf |archive-url=https://web.archive.org/web/20160616175729/http://dillonr.people.cofc.edu/Cowie-et-al-2009.pdf |archive-date=2016-06-16 }}

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File:African Giant Snail 3.jpg

The snail has a bulbous, large, and broad protoconch, with a white or bluish-white columella, parietal wall, and outer lip. The shell of the snail can grow up to 21 cm in height, and 13 cm in diameter. The shell, when magnified, has the appearance of a woven texture.

The snail feeds on a variety of plants, including economically important crops such as bananas, lettuce, peanuts, and peas.{{Cite book|title = The Giant African Snail: A Problem In Economic Malacology|last = Mead|first = Albert|publisher = The University of Chicago Press|year = 1961|location = Chicago, Illinois|pages = 40–49}} There are also possible public health ramifications of the spread of the snail as an invasive species: it is a carrier of the parasitic rat lungworm, which causes angiostrongyliasis, which in turn is the most common cause of the eosinophilic meningitis or eosinophilic meningoencephalitis.

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Achatinids are nocturnal forest dwellers, but can adapt to disturbed habitats. They prefer concealed habitats, and if overcrowding occurs, they may colonize more open habitats. During periods of high humidity, achatinids are more active, but individuals being found during broad daylight are most likely due to high population density.

File:Giant West African Land Snail.jpg

Eggs of achatinids are normally laid in the soil, but can be found under leaves or rocks. They produce as many as 40 eggs, which are yellow in color with dark blotches, and their incubation period is about 40 days.

In this organism's nervous system, the two main types of nerves are pallial and visceral. Pallial nerves are the subject of the majority of scientific research. Visceral nerves are split into the main visceral nerve and the rectal visceral nerve. The main visceral nerve is on the snail's back and connects to a large group of nerve cells to transmit information in the body. The rectal visceral nerve starts further down under the main visceral and extends a short length before branching off near the rectum.{{Cite journal|title = Some Aspects of the Structure and Function of the Nervous System of Archachatina (Calachatina) marginata (Swainson)|journal = Proceedings of the Royal Society of London B: Biological Sciences|date = 1961|pages = 267–288|volume = 154|issue = 955|doi = 10.1098/rspb.1961.0032|first = R. H.|last = Nisbet| bibcode=1961RSPSB.154..267N | s2cid=84036235 }}

Heat can stimulate reactions in the West African snail as a result of the snail's nervous system. The nerves produce warm responsive fibers when the temperature exceeds 25 °C and produce cold responsive fibers when the temperature falls below 19 °C. The ideal temperature range for this species falls between 13 and 32 °C, the thermopreferendum of the species.{{Cite journal|title = Electrophysiological responses to thermal stimuli in peripheral nerves of the African giant snail, Archachatina marginata S.|journal = Journal of Thermal Biology|date = 2001|pages = 21–27|volume = 26|issue = 1|doi = 10.1016/S0306-4565(00)00021-8|pmid = 11070341|first1 = M.|last1 = Voss|first2 = H.|last2 = Schmidt}}

• A. m. var. ovum
• A. m. var. suturalis
• A. m. var. marginata
• A. m. var. egregia
• A. m. var. eduardi
• A. m. var. candefacta
• A. m. var. grevillei
• A. m. var. icterica
• A. m. var. ikom

• List of non-marine molluscs of Nigeria

{{Commons category|Archachatina marginata}}

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Category:Achatinidae

Category:Gastropods described in 1821