Geographic Range
Helix pomatia
is indigenous to Central and Southeast Europe, but has been moved by humans all over
Europe, Asia, and the Americas.
- Biogeographic Regions
- nearctic
- palearctic
- neotropical
Habitat
Helix pomatia
prefers low-lying chalk and limestone areas but can be found up to 1830 meters in
altitude. They can also be seen in vineyards, gardens, thickets and parks. They require
a habitat that is humid with fairly constant, mild temperatures; and they cannot tolerate
heavy rains or direct sunlight.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- Other Habitat Features
- suburban
- agricultural
Physical Description
Helix pomatia
has a brown shell with three to five light brown bands, four to five whorls, and
are round or conical. A mature shell can range from 3.8-5.0 centimeters in height
and diameter and is approximately one-third of their weight.
- Other Physical Features
- ectothermic
- bilateral symmetry
Development
The embryos of Helix pomatia undergo development that is typical of veliger larvae. In the case that an embryo becomes dehydrated, it is usually able to survive. The snails emerge from their shells three to four weeks after they are deposited in a hole dug by their parent, depending on both the temperature and humidity. Each newly-hatched snail typically weighs twenty-seven milligrams and has both male and female reproductive organs. The snails live in the hole dug by the parent for a little over a week, feeding on the empty eggshells.
Shells grow incrementally until they reach maturity. Growth of the shell is inhibited
by adverse weather conditions such as extreme heat or dryness, but eight hours of
sunlight is optimal. Shells cannot reach full development unless they are able to
access a rich calcium carbonate food-source
- Development - Life Cycle
- metamorphosis
Reproduction
Helix pomatia has a mate-selection process in which they court each other for several hours. The mates they ultimately select are usually not from different locations.
The mating process occurs in five steps: (1) With their heads up, snails circle each other and feel one another with their tentacles. (2)After becoming stimulated, one of the snails injects a calcareous “love-dart” into the sole of the other snail. Once it becomes exhausted, the other snail does the same thing. (3)After resting, they align in such a way that their genital openings overlap. This act further stimulates the snails. (4)The two snails twist their bodies around one another so that the penis and vagina are connected. One snail receives a spermatophore in a process that takes four to seven minutes. (5)In the final stage, the penis is removed. However, the two snails can remain attached with their feet together for several hours.
Snails can undergo the aforementioned mating ritual up to two times a year. However,
if they live in a densely populated area, mating activity is reduced because the increased
slime secretion suppresses reproduction.
- Mating System
- polygynandrous (promiscuous)
Mating in
Helix pomatia
usually takes place among mature snails in the late spring and early summer, but
can occur as last as October. After fertilization occurs, the snails can deposit
anywhere from eight to thirty eggs. Sexual maturity is reached in two to four years.
- Key Reproductive Features
- seasonal breeding
- simultaneous hermaphrodite
- sexual
- fertilization
- oviparous
Helix pomatia
typically selects a light, moist, deep soil in order to ensure that its eggs fully
develop. After laying their eggs in a hole, which can take 15-20 minutes per egg,
they cover them with a mixture of slime and soil. No other direct parental care is
provided.
- Parental Investment
- no parental involvement
-
pre-hatching/birth
-
protecting
- male
- female
-
protecting
Lifespan/Longevity
Helix pomatia lives in the wild have a typical lifespan of five years, while those
that are held in captivity can live longer than ten years. Egg deposition affects
lifespan because it causes significant weight loss. Snails that inhabit densely populated
areas also suffer from higher mortality rates. Nematodes, trematodes, fungi, and other
parasite are capable of infecting dense snail populations, causing high mortality.
Behavior
When Helix pomatia forage, a slime trail is left behind. While navigating their surroundings,
they use their slime secretions to move on the rough or slick surfaces. In order
to reduce the loss of water while moving on dry surfaces, they utilize a technique
called “jumping,” which entails using only specific parts of their foot sole. The
snails are able to follow the trail back home, and to return to the food source the
proceeding day. They are nocturnal because of the cooler temperatures at night. The
snails hibernate in the winter because they are not able to survive the cold temperatures
of the winter months. Prior to hibernation, they dig a hole and lay shell-mouth up.
They completely retract into their shells and secrete a mucus covering, called an
epiphragm, to seal the shell’s opening.
- Key Behaviors
- arboreal
- terricolous
- nocturnal
- crepuscular
- motile
- hibernation
Home Range
No specific data was found on this topic.
Communication and Perception
No specific data was found on this topic.
Food Habits
Most feeding occurs between sunset and midnight. While feeding, the snails use their
radula to brush the food. They require a calcium rich food source for shell growth
and maintenance, and also feed on a variety of fruits, vegetables, flowers and leaves.
- Plant Foods
- leaves
- fruit
- flowers
- sap or other plant fluids
Predation
Young
Helix pomatia
are preyed upon by birds, insects, toads and mice. Snail eggs can also be predated
by newly-hatched snails. Secreted slime, although not poisonous or unpalatable, often
deters predation.
Ecosystem Roles
The grazing of Helix pomatia potentially has important effects on the plant community
Economic Importance for Humans: Positive
Helix pomatia
is cultivated and eaten as food.
- Positive Impacts
- food
Economic Importance for Humans: Negative
Helix pomatia
can cause significant crop damage
- Negative Impacts
- crop pest
Conservation Status
Helix pomatia
or its habitat receives some level of protection throughout much of Europe, even
where introduced such as the United Kingdom.
Additional Links
Contributors
Jacqueline Lach (author), Rutgers University, Michelle Schwartz (author), Rutgers University, David Howe (editor, instructor), Rutgers University .
- Nearctic
-
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- Palearctic
-
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- introduced
-
referring to animal species that have been transported to and established populations in regions outside of their natural range, usually through human action.
- temperate
-
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
- terrestrial
-
Living on the ground.
- tropical savanna and grassland
-
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
- savanna
-
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
- temperate grassland
-
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
- suburban
-
living in residential areas on the outskirts of large cities or towns.
- agricultural
-
living in landscapes dominated by human agriculture.
- ectothermic
-
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- metamorphosis
-
A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- arboreal
-
Referring to an animal that lives in trees; tree-climbing.
- nocturnal
-
active during the night
- crepuscular
-
active at dawn and dusk
- motile
-
having the capacity to move from one place to another.
- hibernation
-
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
- food
-
A substance that provides both nutrients and energy to a living thing.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- folivore
-
an animal that mainly eats leaves.
- frugivore
-
an animal that mainly eats fruit
References
Fretter, V., J. Peake. 1975. Pulmonates, Volume I . London: Academic Press.
Rogers, J. 1908. The Shell Book . Boston, MA: Charles T. Branford CO.
2007. "All You Need to Know About Snails" (On-line). Accessed November 01, 2007 at http://www.escargot.fr/uk/tout.htm .
2007. "Helix Pomatia" (On-line). The Trail of the Snail. Accessed October 17, 2007 at http://www.arnobrosi.com/pomatia.html .
Joint Nature Conservation Committee. Second Report by the United Kingdom under Article 17 on the implementation of the Directive from from January 2001 to December 2006. S1026 - Helix pomatia - Roman snail. Peterborough: Joint Nature Conservation Committee. 2007. Accessed October 21, 2008 at www.jncc.gov.uk/article17 .
2007. "The Living World of Molluscs" (On-line). Amazing Facts About Snails. Accessed November 01, 2007 at http://weichtiere.at/english/gastropoda/index.html .
U.S Department of Agriculture. 1996. "U.S Department of Agriculture" (On-line). Raising Snails. Accessed October 17, 2007 at http://www.nal.usda.gov/afsic/AFSIC_pubs/srb96-05.htm .