East African giant snails take a toll on native biodiversity
PUNE:
Deep in the evergreen forests of the Kalakkad Mundanthurai Tiger
Reserve in Tamil Nadu, researchers have recorded the presence of a
population of the Giant African Snail, a native of East Africa that has
come to be recognized as the second worst invasive alien species in the
world.
benson, a pioneer in the study of molluscs, who had brought a pair from Mauritius. He gave them to a friend, who released the snails in his garden in Kolkata. In a decade's time, the snails were ubiquitous in Kolkata and soon were introduced to various parts of the country, said N A Aravind Madhyastha, fellow at the Ashoka Trust for Research in Ecology and the Environment (ATREE).
The Giant African Snail is just one of the several invasive species that are a cause of concern to researchers and conservationists. The plant Lantana that was introduced in several parts of the world for its ornamental value has emerged as the biggest threat to local biodiversity. There are several others that are proving to be a menace to the local ecosystems.
"The snail is a voracious eater and known to feed on more than 500 species of native plants, including agricultural crops, however, many of the native snails tend to be specific in their food preference. Moreover, there are no natural enemies of the Giant African Snail and it is able to prosper at the cost of the local biodiversity," Madhyastha explained.
It breeds very fast and lays a large number of eggs. Even the success rate of hatching of the eggs is rather high, he added.
The Giant African Snail has been introduced to various parts of India by humans. It was introduced either accidentally along with agriculture or horticulture produce or deliberately as pets or for its ornamental, medicinal or food value. On the other hand, the range of the endemic snails of the Western Ghats is extremely limited, he said.
The presence of the snail has already been recorded from several sites in the Western Ghats including Nashik, Pune, Mangalore, Karkala, southern Western Ghats and recently in Goa. The records in protected areas such as the Kudremukh National Park and the Kalakkad Mundanthurai Tiger Reserve are particularly disturbing. Despite its growing presence in the mountain ranges, no studies have been conducted to assess whether it has been responsible for the local extinction of endemic snails.
The threat posed by an invasive species like the Giant African Snail is not limited to local snails alone; its presence could be devastating for an entire eco-system. The snail prefers to eat the tender shoots and young leaves or young seedlings and saplings. Thus it affects re-generation of native flora and pose a major threat to the native plants of the region, Madhyastha said.
Although the snail is not found in very high altitudes as it cannot thrive in extreme cold, the Western Ghats as a region of high rainfall provide it an ideal habitat. Snails require a lot of moisture and do well in regions of high rainfall and tropical weather, he said.
benson, a pioneer in the study of molluscs, who had brought a pair from Mauritius. He gave them to a friend, who released the snails in his garden in Kolkata. In a decade's time, the snails were ubiquitous in Kolkata and soon were introduced to various parts of the country, said N A Aravind Madhyastha, fellow at the Ashoka Trust for Research in Ecology and the Environment (ATREE).
The Giant African Snail is just one of the several invasive species that are a cause of concern to researchers and conservationists. The plant Lantana that was introduced in several parts of the world for its ornamental value has emerged as the biggest threat to local biodiversity. There are several others that are proving to be a menace to the local ecosystems.
"The snail is a voracious eater and known to feed on more than 500 species of native plants, including agricultural crops, however, many of the native snails tend to be specific in their food preference. Moreover, there are no natural enemies of the Giant African Snail and it is able to prosper at the cost of the local biodiversity," Madhyastha explained.
It breeds very fast and lays a large number of eggs. Even the success rate of hatching of the eggs is rather high, he added.
The Giant African Snail has been introduced to various parts of India by humans. It was introduced either accidentally along with agriculture or horticulture produce or deliberately as pets or for its ornamental, medicinal or food value. On the other hand, the range of the endemic snails of the Western Ghats is extremely limited, he said.
The presence of the snail has already been recorded from several sites in the Western Ghats including Nashik, Pune, Mangalore, Karkala, southern Western Ghats and recently in Goa. The records in protected areas such as the Kudremukh National Park and the Kalakkad Mundanthurai Tiger Reserve are particularly disturbing. Despite its growing presence in the mountain ranges, no studies have been conducted to assess whether it has been responsible for the local extinction of endemic snails.
The threat posed by an invasive species like the Giant African Snail is not limited to local snails alone; its presence could be devastating for an entire eco-system. The snail prefers to eat the tender shoots and young leaves or young seedlings and saplings. Thus it affects re-generation of native flora and pose a major threat to the native plants of the region, Madhyastha said.
Although the snail is not found in very high altitudes as it cannot thrive in extreme cold, the Western Ghats as a region of high rainfall provide it an ideal habitat. Snails require a lot of moisture and do well in regions of high rainfall and tropical weather, he said.
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| By NYCRuss [Public domain], via Wikimedia Commons | ||
| William Henry Benson MOST WANTED | ||
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William Henry Benson (1803, probably in Dublin - 27 January 1870) was a civil servant in British India and an amateur malacologist. He made large collections of molluscs and described numerous species from the U.K., India and South Africa.
He joined Haileybury College in 1819 and joined the East India Company at Bengal. He reached Calcutta on 30 October 1821 and worked in a number of positions including a District Collector and Officiating Judge in Meerut, Bareilly and other parts of northern India. During his stay in India he collected specimens of numerous land snails some of which he sent to Hugh Cuming in England. On the return from a trip to Mauritius he brought a couple of living Achatina fulica which he gave to a friend in Calcutta in April 1847 who subsequently released them in a garden at Chowringhee. The species is today a pest in many parts of India. His son-in-law Major Richard Sankey was executor of his estate and the collections that he bequeathed went to Sylvanus Hanley, who removed the locality labels of all the specimens thus decreasing their value. more from Wikipedia | ||
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William Henry Benson - Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/William_Henry_Benson
William Benson and the early study of land snails in
www.nhm.ac.uk/resources/research-curation/.../archiv_nat_hist.pdf
Giant African Snail
Animal
Achatina
fulica is a species of land snail in the family Achatinidae, known
commonly as the giant African snail or giant African land snail.
Outside of its native range this snail thrives in many types of habitat
in areas with mild climates. Wikipedia
Scientific name: Achatina fulica
Rank: Species
The
World’s Departments of Agriculture
MOST WANTED ESCAPED SNAIL! (As well as being the # 2 most wanted species world-wide!) |
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Giant
African Land Snail
On the loose and considered extremely dangerous! The Giant African Land Snail is considered one of the most damaging land snails in the world. There is a very large (and often illegal) "Pet Trade" for these snails even thought it is illegal to keep them in many countries!
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Names: 1. Achatina fulica (East African Land Snail, giant African snail ) 2. Achatina marginata (West African Land Snail, margies) 3. Achatina achatina (Giant Ghana tiger snail) Aliases:
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General
Description:
1.
Achatina fulica is the largest and commonest giant African
land snail, and although originally from East Africa is now distributed
throughout the tropics. It may reach maturity in captivity in just
over one year but this can take four or five years in the wild. It
lays small yellowish white eggs about 4 mm in diameter. With a shell
length averaging in adults at 250 mm the snail weighs about 250 grams.
The shell is a brown colour with weak darker markings that appear
as bands across the spiral. The mantle, the fleshy part inside the
shell through which the foot protrudes, is a pale yellowish colour.
The columella, the smooth inner surface to the opening of the shell
is also yellow. The ‘head’ portion of the foot is light brown but
the rest of the foot is paler with thin net-like markings.
2.
Archachatina marginata is again about 200 mm when full grown.
The shell is much less pointed than the Achatina species and this
‘roundness’ is especially obvious in young animals. The columella
is white and the eggs are comparatively large at 17 x 12 mm. The striation
on the shell may give the appearance of a ‘woven’ texture, especially
when looked at under a magnifying lens. The head is a dark grey but
the rest of the foot is a lighter shade. Its ranges from Zaire to
the Ivory Coast. The snails’ ability to eat virtually any form of
plant material combined with their capacity to build up large populations
rapidly, means that they can be serious agricultural pests. Indeed,
in suitable habitats the snail is able to maintain populations averaging
150 per square meter.
3.
Achatina achatina grows to about 200 mm and has a much more patterned
shell than Achatina fulica the shell is slightly more
yellow with distinct brown jagged bands. On the shell can be seen
striations that are distinctly and regularly broken. The columella
is purple and the eggs are about 6 mm in diameter and obviously yellow
in colour. This species comes from West Africa from Liberia to Nigeria.
Descriptions
derived from the Ameyzoo,
Britain care sheets |
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Sex:
Giant
african land snails contain both male and female reproductive organs
( called hermaphrodites - This does NOT mean that they can mate with
themselves, they still require a partner).
After a single mating they can produce a number of batches of fertile
eggs over a period of months. They can lay as many as 100 to 400 eggs
in a single session , and can lay up to 1,200 eggs per year.
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Life
Span: Average about 5-6 years, but can live up to 10 years. |
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Eating
Habits: Many GALS are voraceous plant feeders and can be very destructive to landscape and homes. |
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Offenses:
1. Giant
African snails have a voracious appetite. They are known to eat at least
500 different types of plants, including peanut, beans, peas, cucumbers,
and melons. If fruits or vegetables are not available, the snails will
eat a wide variety of ornamental plants, tree bark, and even paint and
stucco on houses.
2.
Giant African Snails are carriers of the rat parasite, Angiostrongylus
cantonensis. This parasite can be contracted by ingesting improperly
cooked snail meat or by handling live snails and transferring snail
mucus to the human mucus membranes such as those in the eyes, nose,
and mouth. (For information, see http://www.cdc.gov,
or call your state health department). GALS can also carry several other
human pathogens and parasites.
3.
When these snails are introduced into a nonnative environments, they
can reach such enormous numbers they can become a serious conservation
problem as well. They may eat native the plants modifying that habitat
and they probably also out-compete native snails.
4.
Often on these snails being released into an environment, man has purposefully
introducted other predatory snails and flatworms as biological control
agents. These species then too may have devastating effects on native
land snail diversity and that ecosystem as well.
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Interesting
Facts:
Guiness
World Book of Records: The largest known land gastropod is the African
giant snail (Achatina achatina), the largest recorded specimen of which
measured 39.3 cm (15.5 in) from snout to tail, with a shell length of
27.3 cm (10.75 in) and weight of 900 g (2 lb).
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Legalities
of Keeping Achatinas:
Giant African land snails are illegal in the US and many other countries due to their potential as a devastating invasive species. They are highly invasive, and can cause extensive damage to important food crops and other agricultural and natural resources.
In
the USA, Giant African Snails are strictly prohibited from entering
the United States and they will be removed when discovered.
GALS
are legal pets in many places, However, under no circumstances should
they be kept as pets where illegal to do so.
There
are many alternative snail species that may be used with your science
curricula. Ideally, snails that you collect locally
can be used to teach about native fauna, and these can be used without
a permit. Teachers: Currently the U.S. Department
of Agriculture is reviewing permit procedures for exotic mollusks for
educational purposes on a state by state basis. For more information
on obtaining a permit, please visit http://www.aphis.usda.gov/ppq/permits/plantpest/snails_slugs.html
If
you do have a pet African landsnail, never ever release
it or it's offspring into the wild. NOTE: they are prolific breeders
so if you have more than one you also need to be extremely careful about
disposing of the numerous eggs produced.
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World
Contacts For Information:
United
States of America:
If you have
a giant African land snail PLEASE DO NOT RELEASE IT INTO THE ENVIRONMENT
OR GIVE IT AWAY; OR, or if you find giant african land snail, PLEASE
report it to your State Department of Agriculture (you will find this
office listed under State government in your phone book, or on the web
at: http://www.aphis.usda.gov/npb/npbmemb.html#Members),
or to the US Department of Agriculture Animal and Plant Health Inspection
Service office in your state (you will find this office in your state
listed under Federal or U.S. government in your phone book, or on the
web at: http://www.ceris.purdue.edu/napis/names/sphdXstate.html).
 The U. S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) is interested in finding these snails, and encourages those using these snails in classrooms, nature facilities, or keeping them as pets to turn them in voluntarily without fear of penalty. At the present time snails found in the United States have not been shown to be disease carriers. For more information, see the following web site: http://www.cdc.gov/ncidod/dpd/parasites/angiostrongylus/factsht_angiostrongylus.htm. Canada:  :
Brazil:  |
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REWARD
By
not having these snails as pets or by voluntarily handing in those you
may already have and by reporting any wild-found snails to the appropriate
authorities you will be helping to control one of the world's most destructive
snails. Consequently; you will be part of the solution not the problem
and YOU WILL FEEL GOOD!
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Other
Giant African Land Snail Species: Besides
the species listed below, there are many more species to be found in
other countries. Only the three discussed above
are normally kept as pets.
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Good
Web Sites for more information:
Good Pictures:
Pet Sites: | |||||||||||
do you think this portrait is of W.H Benson ?
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