Helix aspersa
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| Helix aspersa (Müller, 1774) |
The brown garden snail (Helix aspersa) (syn. Cornu aspersum, Cantareus aspersus[1]) is one of the most well-known terrestrial molluscs. Its relationship with humans is multifaceted: it is an agricultural and garden pest, an edible delicacy, and occasionally a household pet.
[edit] Description
The adult snail bears a hard, thin calcareous shell approximately 3 centimeters in diameter, with four or five whorls. The shell is somewhat variable in color and shade but is generally dark brown or chestnut with yellow stripes, flecks, or streaks. The snail's gray or brownish body is soft and slimy, and is retracted entirely into the shell when the animal is inactive or threatened. During dry and cold seasons, the aperture of the shell is sealed with a thin membrane called the epiphragm, which helps the snail retain moisture. During times of activity the head and foot emerge. The head bears four tentacles, two of which have eyes, and two of which are smaller, tactile sensory structures. The tentacles can be retracted into the head. The mouth is located beneath the tentacles and contains a chitinous radula which the snail uses to scrape and manipulate food particles. The snail's muscular foot contracts to move the animal, and secretes mucus to facilitate locomotion by reducing friction against the substrate.
Like other Pulmonata, the brown garden snail is a hermaphrodite, producing both male and female gametes. During a mating session of several hours two snails exchange sperm and after a few days each will dig a nest in the soil and deposit fertilized eggs in it. The young emerge from the eggs after about two weeks, and take one to two years to reach maturity.
[edit] Ecology
The brown garden snail is herbivorous and has a wide range of host plants. It damages numerous types of fruit trees, vegetable crops, garden flowers, and cereals. It was introduced to California as a food animal in the 1850s and is now a notorious agricultural pest there, especially in citrus groves. Many areas have quarantines established for preventing the importation of the snail in plant matter.
The snail is a food source for many other animals, including small mammals, many bird species, lizards, frogs, centipedes, and predatory insects. The decollate snail (Rumina decollata) will capture and eat brown garden snails, so it is sometimes introduced as a biological pest control agent. There is a variety of snail control measures that gardeners and farmers can take to reduce damage. Traditional pesticides are still in use, as are many less toxic control options such as concentrated garlic or wormwood solutions. Copper metal is repellent to snails. A copper band around the trunk of a tree will prevent snails from reaching the foliage and fruit.
The snail has culinary uses. The brown garden snail is known as petit gris in French cuisine where it is served as escargot. The snails are farm-raised or bred as a hobby and enjoyed with garlic butter or cream sauces. Their texture is slightly chewy. The practice of rearing snails for food is known as heliciculture.
[edit] Distribution
- Not listed in IUCN red list - not evaluated (NE)[2]
This snail species is native to Europe, but has been introduced to many regions around the world, from North America to Australia to southern Africa.
- Netherelands[3]
- ...
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[edit] Notes
[edit] References
- ^ The Cornu problem (html). The Living World of Molluscs. Retrieved on March 5, 2007.
- ^ 2006 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Cited 2 April 2007.
- ^ http://www.anemoon.org/anm/voorlopige-kaarten/landmollusken/wetenschappelijk/helix-aspersa
[edit] Sources
- Cranshaw, Whitney. (2004). Garden Insects of North America. Princeton University Press ISBN 0-691-09561-2
[edit] External links
