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Helix aspersa
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Helix aspersa, common name the garden snail; has two recent synonyms: Cornu aspersum and Cantareus aspersus. This pulmonate gastropod is one of the most well-known of all terrestrial molluscs.
It is native to the Mediterranean region and western Europe, from northwest Africa and Iberia east to Asia Minor, and north to the British Isles. However, it is very widely introduced and naturalised elsewhere in the world.
Although this species is edible, it is often regarded as a pest in gardens, especially where it has been accidentally introduced.
This species of snail creates and uses love darts.
adult bears a hard, thin calcareous shell 25–40 mm in diameter and 25–35 mm high, with four or five whorls.
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Encyclopedia
Helix aspersa, common name the garden snail; has two recent synonyms: Cornu aspersum and Cantareus aspersus. This pulmonate gastropod is one of the most well-known of all terrestrial molluscs.
It is native to the Mediterranean region and western Europe, from northwest Africa and Iberia east to Asia Minor, and north to the British Isles. However, it is very widely introduced and naturalised elsewhere in the world.
Although this species is edible, it is often regarded as a pest in gardens, especially where it has been accidentally introduced.
This species of snail creates and uses love darts.
Description
The adult bears a hard, thin calcareous shell 25–40 mm in diameter and 25–35 mm high, with four or five whorls. The shell is somewhat variable in colour and shade but is generally dark brown or chestnut with yellow stripes, flecks, or streaks.
The body is soft and slimy, brownish-grey, and is retracted entirely into the shell when the animal is inactive or threatened. During dry and cold weather, the aperture of the shell is sealed with a thin membrane of dried mucus which is known as an epiphragm, which helps the snail retain moisture. The resultant quiescent periods are known as aestivation and hibernation respectively. When hibernating, Helix aspersa avoids ice formation by altering the osmotic components of its blood (or haemolymph), and can survive temperatures as low as -5°C. During aestivation, the mantle collar has the unique ability to change its permeability to water. In combination with an osmoregulatory mechanism similar to that seen during hibernation this allows Helix aspersa to survive several months of aestivation.
During times of activity the head and foot emerge. The head bears four tentacles, the upper two of which have eye-like light sensors, and the lower two of which are smaller, tactile and olfactory 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.
Snails are Gastropoda, belonging to the phylum Mollusca. This phylum also includes: bivalvia,the family of oysters, mussels and clams; and cephalopoda: squid and octopi.
Behavior
The snail's muscular foot contracts to move the animal, and secretes mucus to facilitate locomotion by reducing friction against the substrate. It moves at a top speed of 1.3 centimetres per second (47 meters per hour), and has a strong homing instinct, readily returning to a regular hibernation site.
Ecology
The 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 is a food source for many other animals, including small mammals, many bird species, lizards, frogs, centipedes, predatory insects, and predatory terrestrial snails.
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.
Helix aspersa can be used as an indicator of environmental contamination, as its shell acts as a site for deposition of toxic heavy metals, such as lead.
The decollate snail (Rumina decollata) will capture and eat garden snails, so it is sometimes introduced as a biological pest control agent.
Reproduction
Like other Pulmonata, Helix aspersa is a hermaphrodite, producing both male and female gametes. Reproduction is usually sexual, although self-fertilisation can occur. During a mating session of several hours, two snails exchange sperm and after about two weeks approximately 80 spherical pearly-white eggs are laid into crevices in the topsoil. Up to six batches of 80 eggs can be laid in a year. The young snails take one to two years to reach maturity. The garden snail uses love darts.
Relationship with humans
The species is an agricultural and garden pest, an edible delicacy, and occasionally a household pet.
In French cuisine, it is known as petit gris, and 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.
Recently, this snail has gained popularity as the chief ingredient in skin creams and gels (crema/gel de caracol) sold within the Latino community and used for wrinkles, scars, dry skin, and acne.
It has been introduced to many regions around the world, including southern Africa, Australia, New Zealand, North America and southern South America. 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.
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