Achatina (Lissachatina) fulica
Giant african land snail
Giant african land snail
Achatinidae (New Latin, from Greek "agate") is a family of medium to large sized tropical land snails, terrestrial pulmonate gastropod mollusks from Africa.
Well known species include Achatina achatina the Giant African Snail, and Lissachatina fulica the Giant East African Snail.
As of 2011 there were recognized 176 extant species and subspecies in 16 genera within Achatinidae.
The native distribution of Achatinidae is Africa south of the Sahara. Lissachatina fulica is a species of large land snail that belongs in the subfamily Achatininae of the family Achatinidae.
It is also known as the Giant African land snail. It shares the common name "giant African snail" with other species of snails such as Achatina achatina and Archachatina marginata.
This snail species has been considered a significant cause of pest issues around the world. Internationally, it is the most frequently occurring invasive species of snail.
Outside of its native range, this snail thrives in many types of habitat in areas with mild climates. It feeds voraciously and is a vector for plant pathogens, causing severe damage to agricultural crops and native plants.
It competes with native snail taxa, is a nuisance pest of urban areas, and spreads human disease. This snail is listed as one of the top 100 invasive species in the world.
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.
The adult snail is around 7 cm (2.8 in) in diameter and 20 cm (7.9 in) or more in length, making it one of the largest of all extant land snails.
The shell has a conical shape, being about twice as long as it is broad. Either clockwise (dextral) or counter-clockwise (sinistral) directions can be observed in the coiling of the shell, although the dextral cone is the more common.
Shell colouration is highly variable, and dependent on diet. Typically, brown is the predominant colour and the shell is banded.
The giant African snail is native to East Africa, and can be traced back to Kenya and Tanzania. It is a highly invasive species, and colonies can be formed from a single gravid individual.
In many places, release into the wild is illegal. Nonetheless, the species has established itself in some temperate climates and its habitat now includes most regions of the humid tropics, including many Pacific islands, southern and eastern Asia, and the Caribbean.
The giant snail can now be found in agricultural areas, coastland, natural forest, planted forests, riparian zones, scrub and shrublands, urban areas, and wetlands.
The giant African snail is a macrophytophagous herbivore; it eats a wide range of plant material, fruit, vegetables, lichens, fungi, paper, and cardboard. It sometimes eats sand, very small stones, bones from carcasses, and even concrete as calcium sources for its shell.
In rare instances, the snails consume each other, snail eggs, and other deceased small animals such as mice and birds.
In captivity, this species can be fed on a wide range of fruit and vegetables, plain unseasoned mince, or boiled egg.
They should always be provided with a source of calcium carbonate such as cuttlefish bone, vital for healthy shell growth. They require about 20% of crude protein in their diet for optimal growth.
This species is a simultaneous hermaphrodite; each individual has both testes and ovaries and is capable of producing both sperm and ova.
The testes typically mature first around 5–8 months, followed by the ovaries. Self-fertilization is not viable and therefore snails require a partner to reproduce. Snails typically mate with a snail of similar size.
During the mating, the snails either simultaneously transfer gametes to each other (bilateral sperm transfer), or one snail transfers sperm into the other (unilateral sperm transfer).
Snails mate at night and their mating begins with courtship rituals that can last up to half an hour, including petting their heads and front parts against each other. One snail initiates the courtship, and if all goes well they begin copulation.
However, copulation does not always occur because snails show mate choice behavior, and observations have shown up to 90% of attempted courtships were rejected and did not end in copulation.
Copulation can last anywhere from 1–24 hours, but tends to last 6–8 hours. Transferred sperm can be stored within the body up to two years.
The snails are oviparous and lay shelled eggs. The number of eggs per clutch and clutches per year varies by environment and age of the parent, but averages around 200 eggs per clutch and 5-6 clutches per year.
The eggs hatch after 1–17 days and the snails emerge as juveniles. They reach adult size in about six months, after which growth slows, but does not cease until death. Life expectancy is 3–5 years in the wild and 5–6 years in captivity, but the snails can live for up to 10 years.
Snails are primarily active at night and spend their days in dark, damp places such as buried in soil or under leaf litter. They are capable of aestivating up to three years in times of extreme drought, sealing itself into its shell by secretion of a calcareous compound that dries on contact with the air.
In many places, this snail is a pest of agriculture and households, with the ability to transmit both human and plant pathogens.
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.
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 (Archachatina marginata) 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 (fried snail meat), which is a delicacy among the 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 countries including France and the UK, where various companies have sold the animal both as a pet and an education aide.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Order: Stylommatophora
Suborder: Achatinina
Superfamily: Achatinoidea
Family: Achatinidae
Genus: Lissachatina
Species: L. fulica
Binomial name Lissachatina fulica
(Férussac, 1821)
Synonyms :
Achatina (Lissachatina) fulica (Férussac, 1821)· accepted, alternate representation Achatina fulica (Férussac, 1821)
Well known species include Achatina achatina the Giant African Snail, and Lissachatina fulica the Giant East African Snail.
As of 2011 there were recognized 176 extant species and subspecies in 16 genera within Achatinidae.
The native distribution of Achatinidae is Africa south of the Sahara. Lissachatina fulica is a species of large land snail that belongs in the subfamily Achatininae of the family Achatinidae.
It is also known as the Giant African land snail. It shares the common name "giant African snail" with other species of snails such as Achatina achatina and Archachatina marginata.
This snail species has been considered a significant cause of pest issues around the world. Internationally, it is the most frequently occurring invasive species of snail.
Outside of its native range, this snail thrives in many types of habitat in areas with mild climates. It feeds voraciously and is a vector for plant pathogens, causing severe damage to agricultural crops and native plants.
It competes with native snail taxa, is a nuisance pest of urban areas, and spreads human disease. This snail is listed as one of the top 100 invasive species in the world.
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.
The adult snail is around 7 cm (2.8 in) in diameter and 20 cm (7.9 in) or more in length, making it one of the largest of all extant land snails.
The shell has a conical shape, being about twice as long as it is broad. Either clockwise (dextral) or counter-clockwise (sinistral) directions can be observed in the coiling of the shell, although the dextral cone is the more common.
Shell colouration is highly variable, and dependent on diet. Typically, brown is the predominant colour and the shell is banded.
The giant African snail is native to East Africa, and can be traced back to Kenya and Tanzania. It is a highly invasive species, and colonies can be formed from a single gravid individual.
In many places, release into the wild is illegal. Nonetheless, the species has established itself in some temperate climates and its habitat now includes most regions of the humid tropics, including many Pacific islands, southern and eastern Asia, and the Caribbean.
The giant snail can now be found in agricultural areas, coastland, natural forest, planted forests, riparian zones, scrub and shrublands, urban areas, and wetlands.
The giant African snail is a macrophytophagous herbivore; it eats a wide range of plant material, fruit, vegetables, lichens, fungi, paper, and cardboard. It sometimes eats sand, very small stones, bones from carcasses, and even concrete as calcium sources for its shell.
In rare instances, the snails consume each other, snail eggs, and other deceased small animals such as mice and birds.
In captivity, this species can be fed on a wide range of fruit and vegetables, plain unseasoned mince, or boiled egg.
They should always be provided with a source of calcium carbonate such as cuttlefish bone, vital for healthy shell growth. They require about 20% of crude protein in their diet for optimal growth.
This species is a simultaneous hermaphrodite; each individual has both testes and ovaries and is capable of producing both sperm and ova.
The testes typically mature first around 5–8 months, followed by the ovaries. Self-fertilization is not viable and therefore snails require a partner to reproduce. Snails typically mate with a snail of similar size.
During the mating, the snails either simultaneously transfer gametes to each other (bilateral sperm transfer), or one snail transfers sperm into the other (unilateral sperm transfer).
Snails mate at night and their mating begins with courtship rituals that can last up to half an hour, including petting their heads and front parts against each other. One snail initiates the courtship, and if all goes well they begin copulation.
However, copulation does not always occur because snails show mate choice behavior, and observations have shown up to 90% of attempted courtships were rejected and did not end in copulation.
Copulation can last anywhere from 1–24 hours, but tends to last 6–8 hours. Transferred sperm can be stored within the body up to two years.
The snails are oviparous and lay shelled eggs. The number of eggs per clutch and clutches per year varies by environment and age of the parent, but averages around 200 eggs per clutch and 5-6 clutches per year.
The eggs hatch after 1–17 days and the snails emerge as juveniles. They reach adult size in about six months, after which growth slows, but does not cease until death. Life expectancy is 3–5 years in the wild and 5–6 years in captivity, but the snails can live for up to 10 years.
Snails are primarily active at night and spend their days in dark, damp places such as buried in soil or under leaf litter. They are capable of aestivating up to three years in times of extreme drought, sealing itself into its shell by secretion of a calcareous compound that dries on contact with the air.
In many places, this snail is a pest of agriculture and households, with the ability to transmit both human and plant pathogens.
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.
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 (Archachatina marginata) 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 (fried snail meat), which is a delicacy among the 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 countries including France and the UK, where various companies have sold the animal both as a pet and an education aide.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Order: Stylommatophora
Suborder: Achatinina
Superfamily: Achatinoidea
Family: Achatinidae
Genus: Lissachatina
Species: L. fulica
Binomial name Lissachatina fulica
(Férussac, 1821)
Synonyms :
Achatina (Lissachatina) fulica (Férussac, 1821)· accepted, alternate representation Achatina fulica (Férussac, 1821)
Limicolaria flammea
Snails by their habitat could be grouped into two: aquatic and terrestrial.
However, terrestrial snails are mostly found in wet and damp areas. Both aquatic and terrestrial snails are hosts to a range of parasites.
Snail consumption rate is rising because people are now avoiding red meat for perceived health reasons. Snail meat offers the entire amino acid requirement in man with relatively high iron content and low fat.
Many of the snails consumed in Nigeria are sourced from the wild, only few are reared, hence, wild snail population have considerably declined. In addition, deforestation, pesticide use and bushfires have further reduced the number of snails.
Land snails are sources of protein to man and are hosts to a number of parasites. It is imperative that the roles of the snail hosts and parasites are clearly defined. Before then however, the parasites of the different land snails collected in any locality should be identified.
Achatinidae (New Latin, from Greek "agate") is a
family of medium to large sized tropical land snails,
terrestrial pulmonate gastropod mollusks from Africa.
Well known species include Achatina achatina the Giant African Snail, and Lissachatina fulica the Giant East African Snail. As of 2011 there were recognized 176 extant species and subspecies in 16 genera within Achatinidae.
The native distribution of Achatinidae is Africa south of the Sahara.
The family Achatinidae is classified within the informal group Sigmurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
Limicolaria flammea is a species of tropical air-breathing land snails, terrestrial pulmonate
gastropod mollusks in the family Achatinidae.
Phylum: Mollusca
Class: Gastropoda
(unranked):
clade Heterobranchia
clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
informal group Sigmurethra
Superfamily: Achatinoidea
Family: Achatinidae
Subfamily: Limicolariinae
Genus: Limicolaria
Schumacher, 1817
Species: L. flammea
Binomial name Limicolaria flammea
(Müller, 1774)
However, terrestrial snails are mostly found in wet and damp areas. Both aquatic and terrestrial snails are hosts to a range of parasites.
Snail consumption rate is rising because people are now avoiding red meat for perceived health reasons. Snail meat offers the entire amino acid requirement in man with relatively high iron content and low fat.
Many of the snails consumed in Nigeria are sourced from the wild, only few are reared, hence, wild snail population have considerably declined. In addition, deforestation, pesticide use and bushfires have further reduced the number of snails.
Land snails are sources of protein to man and are hosts to a number of parasites. It is imperative that the roles of the snail hosts and parasites are clearly defined. Before then however, the parasites of the different land snails collected in any locality should be identified.
Achatinidae (New Latin, from Greek "agate") is a
family of medium to large sized tropical land snails,
terrestrial pulmonate gastropod mollusks from Africa.
Well known species include Achatina achatina the Giant African Snail, and Lissachatina fulica the Giant East African Snail. As of 2011 there were recognized 176 extant species and subspecies in 16 genera within Achatinidae.
The native distribution of Achatinidae is Africa south of the Sahara.
The family Achatinidae is classified within the informal group Sigmurethra, itself belonging to the clade Stylommatophora within the clade Eupulmonata (according to taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
Limicolaria flammea is a species of tropical air-breathing land snails, terrestrial pulmonate
gastropod mollusks in the family Achatinidae.
Phylum: Mollusca
Class: Gastropoda
(unranked):
clade Heterobranchia
clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
informal group Sigmurethra
Superfamily: Achatinoidea
Family: Achatinidae
Subfamily: Limicolariinae
Genus: Limicolaria
Schumacher, 1817
Species: L. flammea
Binomial name Limicolaria flammea
(Müller, 1774)
Pomacea canaliculat
Golden apple snail or the channeled apple snail
Golden apple snail or the channeled apple snail
Pomacea canaliculata, commonly known as the golden apple snail or the channeled apple snail, is a species of large freshwater snail with gills and an operculum, an aquatic gastropod mollusc in the family Ampullariidae
the apple snails.
It is South American in origin, this species is considered to be in the top 100 of the "World's Worst Invasive Alien Species". It is also ranked as the 40th worst alien species in Europe and the worst alien species of gastropod in Europe.
The native distribution of P. canaliculata is basically tropical and subtropical, including Argentina,
Bolivia, Paraguay, Uruguay, and Brazil.
The southernmost record for the species is Paso de las Piedras reservoir, south of the Buenos Aires province, Argentina.
The species has also been found in the Philippines, Japan, Korea, Taiwan, Vietnam, Cambodia, Laos, Papua New Guinea, parts of Indonesia and Malaysia, Singapore, and Guam.
In 1980, the apple snail was introduced to south-east Asia as a food item and aquarium pet. First, it was introduced to Taiwan follow by Japan, then Thailand and the Philippines.
The shells of these applesnails are globular in shape. Normal coloration typically includes bands of brown, black, and yellowish-tan; color patterns are extremely variable. Albino and gold color variations exist.
The size of the shell is up to 150 millimetres (6 in) in length.
This species lives in freshwater lake, river, pond and swamp habitats and tolerates a wide range of temperatures. In natural settings, they rely on grasses and other emergent vegetation growing along the perimeter of bodies of water to lay their eggs. Where invasive, they can utilize crops such as rice and taro as a substrate for reproduction.
Pomacea canaliculata is extremely polyphagous, feeding on vegetal (primarily macrophytophagous, feeding on floating or submersed higher plants), detrital, and animal matter. Diet may vary with age, with younger smaller individuals feeding on algae and detritus, and older, bigger (15 millimetres (19⁄32 in) and above) individuals later shifting to higher plants.
This species negatively impacts rice and taro agriculture worldwide where it has been introduced.
In temperate climates, the egg-laying period of this species extends from early spring to early fall. while in tropical areas reproduction is continuous. The duration of the reproductive period of P. canaliculata decreases with latitude, to a minimum of six months in the southern limit of its natural distribution.
Adult females oviposit on emergent vegetation at night, but will also lay their eggs on rocks and manmade surfaces like boats. Once laid, the eggs take approximately two weeks to hatch, during which time the bright pink or orange coloration of the eggs fades.
Approximately 1% of the Pomacea canaliculata on sale on local markets in Dali City, Yunnan, China were found to be infected with pathogenic Angiostrongylus cantonensis in 2009.
This species is edible. Pomacea canaliculata constitutes one of the three predominant freshwater snails found in Chinese markets. In China and Southeast Asia, consumption of raw or undercooked snails of Pomacea canaliculata and other snails is the primary route of infection with Angiostrongylus cantonensis causing angiostrongyliasis.
In Isan, Thailand these snails are collected and consumed. They are picked by hand or with a hand-net from canals, swamps, ponds, and flooded paddy fields during the rainy season. During the dry season when these snails are concealed under dried mud, collectors use a spade to scrape the mud in order to find them.
After collection, the snails are cleaned and parboiled. They are then taken out of their shells, cut, and cleaned in salted water. After rinsing with water, they are mixed with roasted rice, dried chili pepper, lime juice, and fish sauce, and then eaten.
Special dishes, dish name is 田螺塞肉, using Pomacea canaliculata are also produced in China.
Some French restaurants are trying to use Pomacea canaliculata as an alternative to escargot. After boiling, remove Pomacea canaliculata guts and eggs. Washing only the muscular body with vinegar will eliminate the odor. As a result, it can be used as an alternative to escargot.
Pomacea canaliculata has displaced some of the indigenous rice field apple snail species in the genus Pila traditionally eaten in Southeast Asia (including Thailand and the Philippines) such as Pila ampullacea and Pila pesmei; as well as the viviparid trapdoor snail (Cipangopaludina chinensis).
In some paddy fields in Japan, Pomacea canaliulata is used to control weeds by allowing the snail to eat them. However, this method runs risk of the snails also eating young rice plants, and of spreading to nearby fields and waterways as an invasive pest.
It is also a part of the ornamental pet trade for freshwater aquaria.
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Caenogastropoda
informal group Architaenioglossa
Superfamily: Ampullarioidea
Family: Ampullariidae
Genus: Pomacea
Subgenus: Pomacea
Species: Pomacea canaliculata
(Lamarck, 1819)
the apple snails.
It is South American in origin, this species is considered to be in the top 100 of the "World's Worst Invasive Alien Species". It is also ranked as the 40th worst alien species in Europe and the worst alien species of gastropod in Europe.
The native distribution of P. canaliculata is basically tropical and subtropical, including Argentina,
Bolivia, Paraguay, Uruguay, and Brazil.
The southernmost record for the species is Paso de las Piedras reservoir, south of the Buenos Aires province, Argentina.
The species has also been found in the Philippines, Japan, Korea, Taiwan, Vietnam, Cambodia, Laos, Papua New Guinea, parts of Indonesia and Malaysia, Singapore, and Guam.
In 1980, the apple snail was introduced to south-east Asia as a food item and aquarium pet. First, it was introduced to Taiwan follow by Japan, then Thailand and the Philippines.
The shells of these applesnails are globular in shape. Normal coloration typically includes bands of brown, black, and yellowish-tan; color patterns are extremely variable. Albino and gold color variations exist.
The size of the shell is up to 150 millimetres (6 in) in length.
This species lives in freshwater lake, river, pond and swamp habitats and tolerates a wide range of temperatures. In natural settings, they rely on grasses and other emergent vegetation growing along the perimeter of bodies of water to lay their eggs. Where invasive, they can utilize crops such as rice and taro as a substrate for reproduction.
Pomacea canaliculata is extremely polyphagous, feeding on vegetal (primarily macrophytophagous, feeding on floating or submersed higher plants), detrital, and animal matter. Diet may vary with age, with younger smaller individuals feeding on algae and detritus, and older, bigger (15 millimetres (19⁄32 in) and above) individuals later shifting to higher plants.
This species negatively impacts rice and taro agriculture worldwide where it has been introduced.
In temperate climates, the egg-laying period of this species extends from early spring to early fall. while in tropical areas reproduction is continuous. The duration of the reproductive period of P. canaliculata decreases with latitude, to a minimum of six months in the southern limit of its natural distribution.
Adult females oviposit on emergent vegetation at night, but will also lay their eggs on rocks and manmade surfaces like boats. Once laid, the eggs take approximately two weeks to hatch, during which time the bright pink or orange coloration of the eggs fades.
Approximately 1% of the Pomacea canaliculata on sale on local markets in Dali City, Yunnan, China were found to be infected with pathogenic Angiostrongylus cantonensis in 2009.
This species is edible. Pomacea canaliculata constitutes one of the three predominant freshwater snails found in Chinese markets. In China and Southeast Asia, consumption of raw or undercooked snails of Pomacea canaliculata and other snails is the primary route of infection with Angiostrongylus cantonensis causing angiostrongyliasis.
In Isan, Thailand these snails are collected and consumed. They are picked by hand or with a hand-net from canals, swamps, ponds, and flooded paddy fields during the rainy season. During the dry season when these snails are concealed under dried mud, collectors use a spade to scrape the mud in order to find them.
After collection, the snails are cleaned and parboiled. They are then taken out of their shells, cut, and cleaned in salted water. After rinsing with water, they are mixed with roasted rice, dried chili pepper, lime juice, and fish sauce, and then eaten.
Special dishes, dish name is 田螺塞肉, using Pomacea canaliculata are also produced in China.
Some French restaurants are trying to use Pomacea canaliculata as an alternative to escargot. After boiling, remove Pomacea canaliculata guts and eggs. Washing only the muscular body with vinegar will eliminate the odor. As a result, it can be used as an alternative to escargot.
Pomacea canaliculata has displaced some of the indigenous rice field apple snail species in the genus Pila traditionally eaten in Southeast Asia (including Thailand and the Philippines) such as Pila ampullacea and Pila pesmei; as well as the viviparid trapdoor snail (Cipangopaludina chinensis).
In some paddy fields in Japan, Pomacea canaliulata is used to control weeds by allowing the snail to eat them. However, this method runs risk of the snails also eating young rice plants, and of spreading to nearby fields and waterways as an invasive pest.
It is also a part of the ornamental pet trade for freshwater aquaria.
Phylum: Mollusca
Class: Gastropoda
(unranked): clade Caenogastropoda
informal group Architaenioglossa
Superfamily: Ampullarioidea
Family: Ampullariidae
Genus: Pomacea
Subgenus: Pomacea
Species: Pomacea canaliculata
(Lamarck, 1819)
Parmarion martensi
Ariophantidae is a taxonomic family of air-breathing land snails and semi-slugs, terrestrial pulmonate gastropod mollusks in the superfamily Helicarionoidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).
The distribution of the family Ariophantidae includes India and south-eastern Asia.
Parmarion martensi is a species of air-breathing land semislug, a terrestrial pulmonate gastropod mollusk in the family Ariophantidae.
The probable native distribution of Parmarion martensi includes Southeast Asia.
This species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine significance in the USA.
Parmarion martensi is considered to be a pest species in Hawaii, it is a host for the nematode Angiostrongylus cantonensis, which causes rat lungworm disease.
Parmarion martensi feeds on lettuce and on papaya in gardens in Hawaii, and is considered to be a pest.
Phylum: Mollusca
Class: Gastropoda
(unranked):
clade Heterobranchia clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
clade Sigmurethra
clade limacoid clade
Superfamily: Helicarionoidea
Family: Ariophantidae
Subfamily: Ostracolethinae
Genus: Parmarion
Species: P. martensi
Binomial name Parmarion martensi
Simroth, 1893
The distribution of the family Ariophantidae includes India and south-eastern Asia.
Parmarion martensi is a species of air-breathing land semislug, a terrestrial pulmonate gastropod mollusk in the family Ariophantidae.
The probable native distribution of Parmarion martensi includes Southeast Asia.
This species is already established in the USA, and is considered to represent a potentially serious threat as a pest, an invasive species which could negatively affect agriculture, natural ecosystems, human health or commerce. Therefore it has been suggested that this species be given top national quarantine significance in the USA.
Parmarion martensi is considered to be a pest species in Hawaii, it is a host for the nematode Angiostrongylus cantonensis, which causes rat lungworm disease.
Parmarion martensi feeds on lettuce and on papaya in gardens in Hawaii, and is considered to be a pest.
Phylum: Mollusca
Class: Gastropoda
(unranked):
clade Heterobranchia clade Euthyneura
clade Panpulmonata
clade Eupulmonata
clade Stylommatophora
clade Sigmurethra
clade limacoid clade
Superfamily: Helicarionoidea
Family: Ariophantidae
Subfamily: Ostracolethinae
Genus: Parmarion
Species: P. martensi
Binomial name Parmarion martensi
Simroth, 1893
Oxychilus alliarius
Glass snails
Glass snails
Oxychilus is a genus of small air-breathing land snails, terrestrial pulmonate gastropods in the family Oxychilidae, the glass snails.
There are more than 100 (at least 107 including synonyms) species in the genus Oxychilus.
Oxychilus alliarius, commonly known as the garlic snail or garlic glass-snail, is a species of small, air-breathing land snail, a terrestrial pulmonate
gastropod mollusk in the glass snail family, Oxychilidae.
The specific name alliarius refers to Allium which means garlic. The common name also refers to the fact that when this animal is disturbed, it gives off a strong smell similar to that of raw garlic.
The 3.5–4 by 5–7 millimetres (0.14 in–0.16 in × 0.20 in–0.28 in) shell has four or four and a half slightly convex whorls. The last whorl is often weakly descending near aperture. Surface glossy and translucent, pale brown or greenish. Animal dark blue-grey, rarely pale grey, with mantle edge of the same colour.
The whorls from whorl 3 onwards are more narrowly coiled than in Oxychilus cellarius, the last whorl descending lower. The umbilicus is wide (one sixth of diameter). The shell is smooth, shiny, weakly reddish to greenish brown. The animal is blackish blue.
The internal ornamentation of the proximal penis consisting of not more than four longitudinal pleats, usually straight, sometimes slightly wavy, but never laterally branched or papillate.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Superorder: Eupulmonata
Order: Stylommatophora
Family: Oxychilidae
Genus: Oxychilus
Species: O. alliarius
Binomial name Oxychilus alliarius
(Miller, 1822)
There are more than 100 (at least 107 including synonyms) species in the genus Oxychilus.
Oxychilus alliarius, commonly known as the garlic snail or garlic glass-snail, is a species of small, air-breathing land snail, a terrestrial pulmonate
gastropod mollusk in the glass snail family, Oxychilidae.
The specific name alliarius refers to Allium which means garlic. The common name also refers to the fact that when this animal is disturbed, it gives off a strong smell similar to that of raw garlic.
The 3.5–4 by 5–7 millimetres (0.14 in–0.16 in × 0.20 in–0.28 in) shell has four or four and a half slightly convex whorls. The last whorl is often weakly descending near aperture. Surface glossy and translucent, pale brown or greenish. Animal dark blue-grey, rarely pale grey, with mantle edge of the same colour.
The whorls from whorl 3 onwards are more narrowly coiled than in Oxychilus cellarius, the last whorl descending lower. The umbilicus is wide (one sixth of diameter). The shell is smooth, shiny, weakly reddish to greenish brown. The animal is blackish blue.
The internal ornamentation of the proximal penis consisting of not more than four longitudinal pleats, usually straight, sometimes slightly wavy, but never laterally branched or papillate.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Superorder: Eupulmonata
Order: Stylommatophora
Family: Oxychilidae
Genus: Oxychilus
Species: O. alliarius
Binomial name Oxychilus alliarius
(Miller, 1822)
Laevicaulis alte
Air breathing tropical leatherleaf land slugs
Air breathing tropical leatherleaf land slugs
Laevicaulis alte is a taxonomic genus of air-breathing, tropical land slugs, terrestrial pulmonate gastropod mollusks in the family Veronicellidae, the leatherleaf slugs.
Laevicaulis alte is a round, dark-coloured slug with no shell, 7 or 8 cm long. Its skin is slightly tuberculated. The central keel is beige in colour. This slug has a unique, very narrow foot; juvenile specimens have a foot 1 mm wide and adult specimens have a foot that is only 4 or 5 mm wide.
The tentacles are small, 2 or 3 mm long, and they are only rarely extended beyond the edge of the mantle. This species is probably indigenous to Africa (western Africa and eastern Africa). This slug is eaten by the frog Rana tigrina.
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semislugs (this is in contrast to the common name snail, which applies to gastropods that have a coiled shell large enough that the animal can fully retract its soft parts into the shell).
Slugs are hermaphrodites, having both female and male reproductive organs. Once a slug has located a mate, they encircle each other and sperm is exchanged through their protruded genitalia. A few days later, the slugs lay approximately thirty eggs in a hole in the ground, or beneath the cover of an object such as a fallen log.
Slugs play an important role in the ecosystem by eating decaying plant material and fungi. Most carnivorous slugs on occasion also eat dead specimens of their own kind.
Slugs can feed on a wide variety of vegetables and herbs, including flowers such as petunias, chrysanthemums, daisies, lobelia, lilies, daffodils, narcissus, gentians, primroses, tuberous begonias, hollyhocks, irises, and fruits such as strawberries. They also feed on carrots, peas, apples, and cabbage that are offered as a sole food source.
In captivity this slug will eat : Dandelion leaves, Tomatoes - it nibbles the skin first and then the pulp, cucumber apples, spinach and carrot. When other items are not available, it will eat dill. In captivity it will not eat : grapes.
Parasites, this slug is an intermediate host for Angiostrongylus cantonensis, the rat lungworm, a round worm, the most common cause of eosinophilic meningoencephalitis. This species lives in dry areas, mostly at lower altitudes.
This slug hatches from eggs. This species has several adaptations for living in dry conditions: a rounded shape with as small as possible surface area, and a narrow foot to reduce evaporation.
Juvenile specimens search for food nearly always at night, and stay buried in the soil during the day. Larger specimens are active during the day sometimes. This slug can grow up from 0.5 cm to approximately 4 cm in length in 7 months.
When attacked, slugs can contract their body, making themselves harder and more compact and more still and round. By doing this, they become firmly attached to the substrate. This, combined with the slippery mucus they produce, makes slugs more difficult for predators to grasp. The unpleasant taste of the mucus is also a deterrent. Slugs can also incapacitate predators through the production of a highly sticky and elastic mucus which can trap predators in the secretion.
Slugs' bodies are made up mostly of water and, without a full-sized shell, their soft tissues are prone to desiccation. They must generate protective mucus to survive.
Many species are most active just after rain because of the moist ground. In drier conditions, they hide in damp places such as under tree bark, fallen logs, rocks and man-made structures, such as planters, to help retain body moisture. Like all other gastropods, they undergo torsion (a 180° twisting of the internal organs) during development. Internally, slug anatomy clearly shows the effects of this rotation—but externally, the bodies of slugs appear more or less symmetrical, except the pneumostome, which is on one side of the animal, normally the right-hand side.
Slugs produce two types of mucus: one is thin and watery, and the other thick and sticky. Both kinds are hygroscopic.
The thin mucus spreads from the foot's centre to its edges, whereas the thick mucus spreads from front to back.
Slugs also produce thick mucus that coats the whole body of the animal. The mucus secreted by the foot contains fibres that help prevent the slug from slipping down vertical surfaces.
The "slime trail" a slug leaves behind has some secondary effects: other slugs coming across a slime trail can recognise the slime trail as produced by one of the same species, which is useful in finding a mate.
Following a slime trail is also part of the hunting behaviour of some carnivorous slugs. Body mucus provides some protection against predators, as it can make the slug hard to pick up and hold by a bird's beak, for example, or the mucus itself can be distasteful. Some slugs can also produce very sticky mucus which can incapacitate predators and can trap them within the secretion.n Some species of slug, such as Limax maximus, secrete slime cords to suspend a pair during copulation.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Superorder:vEupulmonata
Order: Systellommatophora
Family: Veronicellidae
Genus: Laevicaulis
Species: L. alte
Binomial name Laevicaulis alte
(Férussac, 1822)
Laevicaulis alte is a round, dark-coloured slug with no shell, 7 or 8 cm long. Its skin is slightly tuberculated. The central keel is beige in colour. This slug has a unique, very narrow foot; juvenile specimens have a foot 1 mm wide and adult specimens have a foot that is only 4 or 5 mm wide.
The tentacles are small, 2 or 3 mm long, and they are only rarely extended beyond the edge of the mantle. This species is probably indigenous to Africa (western Africa and eastern Africa). This slug is eaten by the frog Rana tigrina.
Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word slug is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a small internal shell, particularly sea slugs and semislugs (this is in contrast to the common name snail, which applies to gastropods that have a coiled shell large enough that the animal can fully retract its soft parts into the shell).
Slugs are hermaphrodites, having both female and male reproductive organs. Once a slug has located a mate, they encircle each other and sperm is exchanged through their protruded genitalia. A few days later, the slugs lay approximately thirty eggs in a hole in the ground, or beneath the cover of an object such as a fallen log.
Slugs play an important role in the ecosystem by eating decaying plant material and fungi. Most carnivorous slugs on occasion also eat dead specimens of their own kind.
Slugs can feed on a wide variety of vegetables and herbs, including flowers such as petunias, chrysanthemums, daisies, lobelia, lilies, daffodils, narcissus, gentians, primroses, tuberous begonias, hollyhocks, irises, and fruits such as strawberries. They also feed on carrots, peas, apples, and cabbage that are offered as a sole food source.
In captivity this slug will eat : Dandelion leaves, Tomatoes - it nibbles the skin first and then the pulp, cucumber apples, spinach and carrot. When other items are not available, it will eat dill. In captivity it will not eat : grapes.
Parasites, this slug is an intermediate host for Angiostrongylus cantonensis, the rat lungworm, a round worm, the most common cause of eosinophilic meningoencephalitis. This species lives in dry areas, mostly at lower altitudes.
This slug hatches from eggs. This species has several adaptations for living in dry conditions: a rounded shape with as small as possible surface area, and a narrow foot to reduce evaporation.
Juvenile specimens search for food nearly always at night, and stay buried in the soil during the day. Larger specimens are active during the day sometimes. This slug can grow up from 0.5 cm to approximately 4 cm in length in 7 months.
When attacked, slugs can contract their body, making themselves harder and more compact and more still and round. By doing this, they become firmly attached to the substrate. This, combined with the slippery mucus they produce, makes slugs more difficult for predators to grasp. The unpleasant taste of the mucus is also a deterrent. Slugs can also incapacitate predators through the production of a highly sticky and elastic mucus which can trap predators in the secretion.
Slugs' bodies are made up mostly of water and, without a full-sized shell, their soft tissues are prone to desiccation. They must generate protective mucus to survive.
Many species are most active just after rain because of the moist ground. In drier conditions, they hide in damp places such as under tree bark, fallen logs, rocks and man-made structures, such as planters, to help retain body moisture. Like all other gastropods, they undergo torsion (a 180° twisting of the internal organs) during development. Internally, slug anatomy clearly shows the effects of this rotation—but externally, the bodies of slugs appear more or less symmetrical, except the pneumostome, which is on one side of the animal, normally the right-hand side.
Slugs produce two types of mucus: one is thin and watery, and the other thick and sticky. Both kinds are hygroscopic.
The thin mucus spreads from the foot's centre to its edges, whereas the thick mucus spreads from front to back.
Slugs also produce thick mucus that coats the whole body of the animal. The mucus secreted by the foot contains fibres that help prevent the slug from slipping down vertical surfaces.
The "slime trail" a slug leaves behind has some secondary effects: other slugs coming across a slime trail can recognise the slime trail as produced by one of the same species, which is useful in finding a mate.
Following a slime trail is also part of the hunting behaviour of some carnivorous slugs. Body mucus provides some protection against predators, as it can make the slug hard to pick up and hold by a bird's beak, for example, or the mucus itself can be distasteful. Some slugs can also produce very sticky mucus which can incapacitate predators and can trap them within the secretion.n Some species of slug, such as Limax maximus, secrete slime cords to suspend a pair during copulation.
Phylum: Mollusca
Class: Gastropoda
Subclass: Heterobranchia
Superorder:vEupulmonata
Order: Systellommatophora
Family: Veronicellidae
Genus: Laevicaulis
Species: L. alte
Binomial name Laevicaulis alte
(Férussac, 1822)
Above sharing diagram is a source from internet ..
Tentacles Like other pulmonate land gastropods, the majority of land slugs have two pairs of 'feelers' or tentacles on their head. The upper pair is light sensing and has eyespots at the ends, while the lower pair provides the sense of smell. Both pairs are retractable.
Mantle On top of the slug, behind the head, is the saddle-shaped mantle, and under this are the genital opening and anus. On one side (almost always the right hand side) of the mantle is a respiratory opening, which is easy to see when open, but difficult to see when closed. This opening is known as the pneumostome.
Tail The part of a slug behind the mantle is called the 'tail'.
Keel Some species of slugs, for example Tandonia budapestensis, have a prominent ridge running over their back along the middle of the tail (sometimes along the whole tail, sometimes only the final part). This ridge is called a 'keel'.
Foot The bottom side of a slug, which is flat, is called the 'foot'. Like almost all gastropods, a slug moves by rhythmic waves of muscular contraction on the underside of its foot. It simultaneously secretes a layer of mucus that it travels on, which helps prevent damage to the foot tissues. Around the edge of the foot in some slugs is a structure called the 'foot fringe'.
Vestigial shell Most slugs retain a remnant of their shell, which is usually internalized. This organ generally serves as storage for calcium salts, often in conjunction with the digestive glands.
Mantle On top of the slug, behind the head, is the saddle-shaped mantle, and under this are the genital opening and anus. On one side (almost always the right hand side) of the mantle is a respiratory opening, which is easy to see when open, but difficult to see when closed. This opening is known as the pneumostome.
Tail The part of a slug behind the mantle is called the 'tail'.
Keel Some species of slugs, for example Tandonia budapestensis, have a prominent ridge running over their back along the middle of the tail (sometimes along the whole tail, sometimes only the final part). This ridge is called a 'keel'.
Foot The bottom side of a slug, which is flat, is called the 'foot'. Like almost all gastropods, a slug moves by rhythmic waves of muscular contraction on the underside of its foot. It simultaneously secretes a layer of mucus that it travels on, which helps prevent damage to the foot tissues. Around the edge of the foot in some slugs is a structure called the 'foot fringe'.
Vestigial shell Most slugs retain a remnant of their shell, which is usually internalized. This organ generally serves as storage for calcium salts, often in conjunction with the digestive glands.
Amphidromous atricallosus temasek
Singapore green tree snail
Singapore green tree snail
Amphidromus atricallosus is a species of air-breathing, arboreal land snail, a terrestrial pulmonate gastropod mollusk in the family Camaenidae.
The shells of Amphidromus are relatively large, from 25 mm (0.98 in) to 75 mm (3.0 in) in maximum dimension, and particularly colorful.
During the 18th century, they were among the first Indonesian land snail shells brought to Europe by travelers and explorers. Since then, the genus has been extensively studied, several comprehensive monographs and catalogs were authored by naturalists and zoologists during the time period from the early 19th to the mid 20th centuries. Modern studies have focused on better understanding the evolutionary relationships within the group, as well as solving taxonomic problems.
The genus Amphidromus is unusual in that it includes species that have dextral shell-coiling and species that have sinistral shell-coiling. In addition, some species within this genus are particularly notable because their populations simultaneously include individuals with left-handed and right-handed shell-coiling. This is an extremely rare phenomenon, and very interesting to biologists. Studies focused on the soft anatomy of Amphidromus are scattered and fragmentary. Information on the internal anatomy is known only from a few species, and no larger, comparative morphological study has ever been carried out.
Species in the genus Amphidromus are arboreal — in other words, they are tree snails. However, more detailed information on their habits is still lacking. The general feeding habits of these snails are unknown, but a few species are known to feed on microscopic fungi, lichens or terrestrial algae. Amphidromus themselves are preyed upon by birds, snakes, and probably also by smaller mammals such as rats.
The generic name is derived from the ancient Greekwords amphí (ἀμφί), meaning "on both sides", and drómos (δρόμος), meaning "running", alluding to the different chiralities of the shells.
The shells of Amphidromus are relatively large, and quite colorful; considerable numbers of them were among the first Indonesian land snail shells brought back to Europe by travelers and explorers during the 18th century. Comparatively speaking, malacologists have gathered a much smaller number of specimens.
Species in the genus Amphidromus usually have smooth, glossy, brightly colored, elongate or conic, dextrally or sinistrally coiled shells. The shells are moderately large, ranging from 25 mm (0.98 in) to 70 mm (2.8 in) in maximum dimension, having from 6 to 8 convex whorls. Their color pattern is usually monochromatic yellowish or greenish, but can be variegated. The aperture is oblique or ovate in shape, without any teeth or folds, and with the aperture height ranging from two-fifths to one-third of total shell height. The peristome is expanded and/or reflected, and is sometimes thickened.
The columella may be straight or recurved, and the parietal callus is weak to well-developed, and the umbilicus may be open or closed. The radula is spatulate, has cusped teeth arranged in rows, usually with a monocuspid central tooth and bicuspid or tricuspid lateral teeth. The jaw is thin and weak, with low flat ribs. The pallial region is sigmurethrous, with a very long, narrow kidney. The genitalia are that of typical camaenids, with a long seminal receptacle, a short penis with low insertion of the retractor muscle, and a short or long epiphallic caecum (flagellum and appendix). The spermatophores have a pentagonal outline in cross-section. Amphidromus are typically arboreal animals.
The shells of Amphidromus are relatively large, from one to three inches high, and colorful. Amphidromus has an elongate-conic or ovate-conic helicoid shell of 5 to 8 whorls. The shell may be thin and fragile, or very heavy and solid, with no known correlation of shell structure with distribution or habitats.
In some species within this genus, the shell coils invariably to the right, and in many others just as invariably to the left. However, a significant number of species in this genus are "amphidromine"; this term means that both left- and right-handed shell coiling are found within the same population. One could say they are "polymorphic" for the direction of shell coiling, but because there are only two possible types of shell coiling, they are described as "dimorphic" in coiling. The two types of shell coiling occur in some species in approximately equal numbers, other species have a distinct predominance of one phase. There is as yet no information on the heredity of this character in Amphidromus.
Because almost all other species of amphidromine gastropods, such as ones within the genera Partula and Achatinella, have already become extinct, the genus Amphidromus, containing over 110 species, is uniquely useful for the study of the evolution of asymmetry in animals, and this is why the conservation of this genus is of essential importance to biologists.
The whorls of the shell of species of Amphidromus are moderately convex and, with only a few exceptions, are smooth or have a faint sculpture of growth lines.
Generally the whorls of the shell increase rather regularly in size. The single most major aspect of shell variation within the genus is the color patterning. In general, many arboreal snails are brightly colored.
The basic ground color of Amphidromus appears to be yellow, and this color is usually (except for Amphidromus entobaptus) confined to the surface layers of the shell, since worn specimens appear to be nearly devoid of color. In some species the background color is whitish, and a few have dark background colors. The apical whorls are pale, purple, brown, or black, and this sometimes varies within a population (as in A. quadrasi). A few species, for example A. schomburgki, have a deciduous green periostracum.
Species recognition is based on combinations of minor structural variations in the shape, aperture, whorl contour, umbilical region, and color pattern. It appears to be the case that many species have a stable color pattern, while other species seem to vary tremendously. Adequate unselected field samples will enable a better understanding of the relative stability or variability of particular species in single localities.
The aperture is generally large, varying from about two-fifths to one-third the height of the shell, often within the same population. Usually the lip is at least somewhat expanded.
The Singapore Green Tree Snail (Amphidromous atricallosus temasek) is found solely in undisturbed forested area and is endemic to Singapore. This means that it exists nowhere else in the world except Singapore.
The Singapore Green Tree Snail can be easily recognised by its very distinct jade green shell and pale body.
The Singapore Green Tree Snail has long been confused with another subspecies Amphidromous atricallosus perakensis which is widely distributed in Peninsular Malaysia. It was only in 2011 that the Singapore Green Tree Snail was recognised as a different subspecies by Mr Tan Siong Kiat, the curator for malacofauna at the Lee Kong Chian Natural History Museum and two of his colleagues.
Singapore Green Tree Snails are also known to be hermaphroditic, which means that a single individual possesses both male and female reproductive organs! However, they still need to find another snail to mate.
Over the years, due to rapid urbanisation, loss of habitat and exploitation by shell collectors, the population of the Singapore Green Tree Snail has declined to a point where it is now listed in the Singapore Red Data Book as an endangered species. Its population is now restricted to certain parts of the Central Catchment Nature Reserve and some of the offshore islands.
Conserving our natural heritage,
In order to better understand and conserve the remaining populations of the Singapore Green Tree Snail, the National Parks Board has embarked on a 2-year study of land snail biodiversity in Central Catchment Nature Reserve. The study aims to assess the population and distribution of all land snails in Central Catchment Nature Reserve, including the Singapore Green Tree Snail.
The study also aims to identify any threat and propose preventive measures to ensure their survival within the forest. Preliminary results show that a healthy population still thrive within Central Catchment Nature Reserve.
The Singapore Green Tree Snail is an important natural heritage, and we should protect it for our future generations to appreciate. We can all do our part by preserving its natural habitat and refrain from collecting its beautiful shell.
Class: Gastropoda
Superfamily: Helicoidea
Family: Camaenidae
Subfamily: Camaeninae
Genus: Amphidromus
Subgenus: Amphidromus
Species: A. atricallosus temasek
Binomial name Amphidromus atricallosus
The shells of Amphidromus are relatively large, from 25 mm (0.98 in) to 75 mm (3.0 in) in maximum dimension, and particularly colorful.
During the 18th century, they were among the first Indonesian land snail shells brought to Europe by travelers and explorers. Since then, the genus has been extensively studied, several comprehensive monographs and catalogs were authored by naturalists and zoologists during the time period from the early 19th to the mid 20th centuries. Modern studies have focused on better understanding the evolutionary relationships within the group, as well as solving taxonomic problems.
The genus Amphidromus is unusual in that it includes species that have dextral shell-coiling and species that have sinistral shell-coiling. In addition, some species within this genus are particularly notable because their populations simultaneously include individuals with left-handed and right-handed shell-coiling. This is an extremely rare phenomenon, and very interesting to biologists. Studies focused on the soft anatomy of Amphidromus are scattered and fragmentary. Information on the internal anatomy is known only from a few species, and no larger, comparative morphological study has ever been carried out.
Species in the genus Amphidromus are arboreal — in other words, they are tree snails. However, more detailed information on their habits is still lacking. The general feeding habits of these snails are unknown, but a few species are known to feed on microscopic fungi, lichens or terrestrial algae. Amphidromus themselves are preyed upon by birds, snakes, and probably also by smaller mammals such as rats.
The generic name is derived from the ancient Greekwords amphí (ἀμφί), meaning "on both sides", and drómos (δρόμος), meaning "running", alluding to the different chiralities of the shells.
The shells of Amphidromus are relatively large, and quite colorful; considerable numbers of them were among the first Indonesian land snail shells brought back to Europe by travelers and explorers during the 18th century. Comparatively speaking, malacologists have gathered a much smaller number of specimens.
Species in the genus Amphidromus usually have smooth, glossy, brightly colored, elongate or conic, dextrally or sinistrally coiled shells. The shells are moderately large, ranging from 25 mm (0.98 in) to 70 mm (2.8 in) in maximum dimension, having from 6 to 8 convex whorls. Their color pattern is usually monochromatic yellowish or greenish, but can be variegated. The aperture is oblique or ovate in shape, without any teeth or folds, and with the aperture height ranging from two-fifths to one-third of total shell height. The peristome is expanded and/or reflected, and is sometimes thickened.
The columella may be straight or recurved, and the parietal callus is weak to well-developed, and the umbilicus may be open or closed. The radula is spatulate, has cusped teeth arranged in rows, usually with a monocuspid central tooth and bicuspid or tricuspid lateral teeth. The jaw is thin and weak, with low flat ribs. The pallial region is sigmurethrous, with a very long, narrow kidney. The genitalia are that of typical camaenids, with a long seminal receptacle, a short penis with low insertion of the retractor muscle, and a short or long epiphallic caecum (flagellum and appendix). The spermatophores have a pentagonal outline in cross-section. Amphidromus are typically arboreal animals.
The shells of Amphidromus are relatively large, from one to three inches high, and colorful. Amphidromus has an elongate-conic or ovate-conic helicoid shell of 5 to 8 whorls. The shell may be thin and fragile, or very heavy and solid, with no known correlation of shell structure with distribution or habitats.
In some species within this genus, the shell coils invariably to the right, and in many others just as invariably to the left. However, a significant number of species in this genus are "amphidromine"; this term means that both left- and right-handed shell coiling are found within the same population. One could say they are "polymorphic" for the direction of shell coiling, but because there are only two possible types of shell coiling, they are described as "dimorphic" in coiling. The two types of shell coiling occur in some species in approximately equal numbers, other species have a distinct predominance of one phase. There is as yet no information on the heredity of this character in Amphidromus.
Because almost all other species of amphidromine gastropods, such as ones within the genera Partula and Achatinella, have already become extinct, the genus Amphidromus, containing over 110 species, is uniquely useful for the study of the evolution of asymmetry in animals, and this is why the conservation of this genus is of essential importance to biologists.
The whorls of the shell of species of Amphidromus are moderately convex and, with only a few exceptions, are smooth or have a faint sculpture of growth lines.
Generally the whorls of the shell increase rather regularly in size. The single most major aspect of shell variation within the genus is the color patterning. In general, many arboreal snails are brightly colored.
The basic ground color of Amphidromus appears to be yellow, and this color is usually (except for Amphidromus entobaptus) confined to the surface layers of the shell, since worn specimens appear to be nearly devoid of color. In some species the background color is whitish, and a few have dark background colors. The apical whorls are pale, purple, brown, or black, and this sometimes varies within a population (as in A. quadrasi). A few species, for example A. schomburgki, have a deciduous green periostracum.
Species recognition is based on combinations of minor structural variations in the shape, aperture, whorl contour, umbilical region, and color pattern. It appears to be the case that many species have a stable color pattern, while other species seem to vary tremendously. Adequate unselected field samples will enable a better understanding of the relative stability or variability of particular species in single localities.
The aperture is generally large, varying from about two-fifths to one-third the height of the shell, often within the same population. Usually the lip is at least somewhat expanded.
The Singapore Green Tree Snail (Amphidromous atricallosus temasek) is found solely in undisturbed forested area and is endemic to Singapore. This means that it exists nowhere else in the world except Singapore.
The Singapore Green Tree Snail can be easily recognised by its very distinct jade green shell and pale body.
The Singapore Green Tree Snail has long been confused with another subspecies Amphidromous atricallosus perakensis which is widely distributed in Peninsular Malaysia. It was only in 2011 that the Singapore Green Tree Snail was recognised as a different subspecies by Mr Tan Siong Kiat, the curator for malacofauna at the Lee Kong Chian Natural History Museum and two of his colleagues.
Singapore Green Tree Snails are also known to be hermaphroditic, which means that a single individual possesses both male and female reproductive organs! However, they still need to find another snail to mate.
Over the years, due to rapid urbanisation, loss of habitat and exploitation by shell collectors, the population of the Singapore Green Tree Snail has declined to a point where it is now listed in the Singapore Red Data Book as an endangered species. Its population is now restricted to certain parts of the Central Catchment Nature Reserve and some of the offshore islands.
Conserving our natural heritage,
In order to better understand and conserve the remaining populations of the Singapore Green Tree Snail, the National Parks Board has embarked on a 2-year study of land snail biodiversity in Central Catchment Nature Reserve. The study aims to assess the population and distribution of all land snails in Central Catchment Nature Reserve, including the Singapore Green Tree Snail.
The study also aims to identify any threat and propose preventive measures to ensure their survival within the forest. Preliminary results show that a healthy population still thrive within Central Catchment Nature Reserve.
The Singapore Green Tree Snail is an important natural heritage, and we should protect it for our future generations to appreciate. We can all do our part by preserving its natural habitat and refrain from collecting its beautiful shell.
Class: Gastropoda
Superfamily: Helicoidea
Family: Camaenidae
Subfamily: Camaeninae
Genus: Amphidromus
Subgenus: Amphidromus
Species: A. atricallosus temasek
Binomial name Amphidromus atricallosus