Lissachatina fulica

Appearance

The eggs of ''Lissachatina fulica'' are pure white and opaque but may be slightly yellowish or even somewhat transparent.contradictory The eggs have a thin, calcareous shell, and are about 5 mm long and 4 mm wide.

A newly hatched snail is called a neonate. When the giant African land snail hatches, its shell is about 5 to 5.5 mm long, consisting of 2.5 whorls. As the snail grows, its shell extends either clockwise or counter-clockwise , coiling and creating whirls as the snail ages.

Younger snails will have a vertical pattern on their shell of brown and cream color bands. As the snail grows, the new whorls of its shell will be smooth and glossy, consisting of only a brown color. A fully adult snail is around 7 cm in diameter and 20 cm or more in length, making it one of the largest of all extant land snails. An adult snail may be expected to have 7-9 whorls, but this is not necessarily a reliable indicator of age; nor is the width of the snail's peristome , which was traditionally used to measure age, as it varies as well.

While the snail most typically has a brown shell with cream sections at its apex, the shell coloration is highly variable. A buttery yellow body is possible, rather than the typical brownish grey body and brown shell. This variety is nicknamed the 'white jade snail' in China. The snail also comes in the 'golden' variety, sometimes considered an albino type; with a yellow body and yellow shell.
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Naming

In many places, this snail is a pest of agriculture and households, with the ability to transmit both human and plant pathogens. Suggested preventive measures include strict quarantine to prevent introduction and further spread. This snail has been given top national quarantine significance in the United States. In the past, quarantine officials have been able to successfully intercept and eradicate incipient invasions on the mainland USA.

This snail was twice established in southeastern Florida and was successfully eradicated both times. They were brought to the U.S. through imports, intended for educational uses and to be pets. Some were also introduced because they were accidentally shipped with other cargo. An eradication effort in Florida began in 2011 when they were first sighted, and the last sighting was in 2017. In October 2021 the Florida Department of Agriculture declared the eradication a success after no further sightings in those four years. In June 2022 the snail was again found in Florida.

In the wild, this species often harbors the parasitic nematode ''Angiostrongylus cantonensis'', which can cause a very serious meningitis in humans. Human cases of this meningitis usually result from a person having eaten the raw or undercooked snail, but even handling live wild snails of this species can infect a person with the nematode, thus causing a life-threatening infection.

In some regions, an effort has been made to promote use of the giant African snail as a food resource to reduce its populations. However, promoting a pest in this way is a controversial measure, because it may encourage the further deliberate spread of the snails.

One particularly catastrophic attempt to biologically control this species occurred on South Pacific Islands. Colonies of ''A. fulica'' were introduced as a food reserve for the American military during World War II and they escaped. A carnivorous species was later introduced by the United States government, in an attempt to control ''A. fulica'', but the rosy wolf snail instead heavily preyed upon the native ''Partula'' snails, causing the extinction of most ''Partula'' species within a decade.

The snail has been eradicated from California , Queensland , Fiji, Western Samoa, Vanuatu, and Wake Island, but these were relatively small populations.

The Argentinian National Agricultural Health Service has established an ongoing project to detect, study, and prevent the expansion of this pest.

In early April 2021, USCBP intercepted 22 being smuggled from Ghana into the US, along with various other prohibited quarantine items.

Distribution

The species is native to East Africa, but it has been widely introduced to other parts of the world through the pet trade, as a food resource, and by accidental introduction.

Within Africa, the snail can be found along the eastern coast of South Africa, extending northward into Somalia. However, some of its distribution into northern African may be due to human introduction, starting in northern Mozambique, Tanzania, Kenya, and extending through Somalia into Ethiopia. The snail has been reported in Morocco, Ghana, and the Ivory Coast as early as the 1980s.

In 1961, Albert R. Mead, published the seminal work entitled "The Giant African Snail: A Problem in Economic Malacology". This book compiled known information on the snail, as well as a detailed overview on its global distribution.

Prior to 1800, the snail was found in Madagascar, spreading westward to Mauritius, reaching Réunion in 1821, then to Seychelles in 1840. In 1847, they were introduced to India and in 1900 in Sri Lanka. In 1911, the snail was present in northern Malaysia, possibly from India or Myanmar. In 1922, the snail was identified in Singapore although it may have been present as early as 1917. In 1925, the snail was shipped to Java, from which it spread across Indonesia. In 1928, the snail was observed in Sarawak.

This species has been found in China since 1931 and its initial point of distribution in China was Xiamen. The snail has also been established on Pratas Island, of Taiwan.

The species was established in Hawaii, United States, by 1936. The snail was present in Papua New Guinea by 1946, spreading from New Ireland and New Britain to the mainland by 1976–77. By 1967 the snail was present in Tahiti, spreading through New Caledonia and Vanuatu by 1972 into French Polynesia by 1978, including America Samoa.

By 1990, the snail was reported in Samoa and the Federated States of Micronesia in 1998.

In 1984, ''L. fulica'' was found established in the French West Indies, spreading across Guadeloupe and by 1988 arriving in Martinique. In 2008, populations of ''L. fulica'' were reported in Trinidad but were greatly reduced by 2010. In 2014, the snail was reported in Havana, Cuba.

In Brazil, the first introduction of ''L. fulica'' came in 1988 in Paraná. By 2007, it was recorded in 23 of the 26 Brazilian states. In 2006–08, the snail was recorded in Ecuador, in Pichincha, and may have been present at least 10 years prior in 'snail farms'. The presence of the snail in Colombia was reported by 2008–2009. Although the time of the initial introduction is unknown, it has been registered in all regions of the country by 2012. Live specimens were found in Piura, Peru, around 2008 as well. The snail may be present in Venezuela and was reported in Puerto Iguazú, Argentina in 2010.

The species has been observed in Bhutan , where it is an invasive species since 2006 and their number increased drastically since 2008.

In the contiguous United States, the snail had been reported in the state of Florida in 2011, and later in 2021–2022; however, the snail has not yet become established.

Habitat

This section needs additional citations for . Please help improve this article by adding citations to reliable sources in this section. Unsourced material may be challenged and removed. Within its native range in Africa, the snail is found along the margins of forests. Within its invasive range it can be found in agricultural areas as well as urban areas. The snails prefer areas that shelter them from light in the daytime and prevent desiccation; examples are leaf litter or piles of debris. It will also climb tree trunks or walls when conditions allow.

''L. fulica'' occurs in a wide range of temperate climates, now including most regions of the humid tropics. The snail can tolerate a broad range of soil pH and calcium conditions, although calcium is critical for snail shell development. Relative humidity, such as the amount of rain, is an important factor for snail growth. In fact, the snail's shell growth pattern will reflect rain fall patterns, much like the growth rings of a tree. The species can tolerate temperatures of 0-9 °C to 45 °C but thrives in temperatures between 22 and 32 °C . When overwintering is necessary, the snail will burrow below the surface and may not lay eggs until temperatures increase to above 15 °C . This tactic to avoid extreme conditions is called aestivating. The snail can survive in an aestivation state for up to three years by sealing itself into its shell by secretion of a calcareous compound that dries on contact with the air.

Food

The giant African snail is a macrophytophagous herbivore; it eats a wide range of living plant material, commercially important fruits and vegetables, ornamental plants such as flowers, native plants, as well as weeds and detritus plant material. At different life stages and temperatures, the snail has slightly different feeding preferences. For example, young snails are likely to consume soil for its calcium content.

Trash, cardboard, and occasionally stucco have been reportedly consumed. Under some conditions the snail will consume dead snails and other deceased animals. It can also be found consuming animal feces as a protein source, which is required for optimal growth.

Cultural

These snails are used by some practitioners of Candomblé for religious purposes in Brazil as an offering to the deity Oxalá. The snails substitute for a closely related species, the West African giant snail normally offered in Nigeria. The two species are similar enough in appearance to satisfy religious authorities. They are also edible if cooked properly.

In Taiwan, this species is used in the dish of 炒螺肉 , which is a delicacy among many traditional drinking snacks. ''L. fulica'' also constitutes the predominant land snail found in Chinese markets, and larger species have potential as small, efficient livestock.

The snails have also become increasingly popular as pets in some countries, where various companies have sold the animal both as a pet and an education aid. In light of social media posts where pet owners share images in close contact with the snails, a research from the University of Lausanne alerted with the risks of infections transmitted to humans.

The heparinoid, acharan sulfate, is isolated from this species.