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The Common or Garden Snail

External features

chalky shell- spirally coiled - continually added to - newest section with growth lines

Head with 2 pairs of tentacles - retractile, i.e. can be withdrawn

- longer upper tentacles each have an eye at the tip
- shorter lower tentacles bear chemosensory organs (equivalent to taste & smell)

mouth with rasping mouthparts on underside (ventral surface)

respiratory opening connects to mantle cavity - similar to lung - inside shell - many blood capillaries - air moved in and out by muscular movements

large muscular foot for creeping locomotion (mucus secreted from slime glands on base as lubricant)

moist skin

Role in ecosystem:

Primary consumer - eats plant material
Eaten by thrushes, which extract soft parts from shell after beating on "anvil" stone.

Adaptations for water conservation

(also general protection) :

Shell, into which body can be withdrawn, and sealed by base of foot as plug.
For long term survival in winter or dry weather - a film of mucus, hardened with calcium salts, can cover the opening.
Enclosed surface for gas exchange.
Behaviour - snails tend to select a damp, shaded habitat ( base of clumps of grass, holes in walls & around tree roots) and come out mostly at night.


Snails are hermaphrodite, but each one produces eggs fertilised by a partner (cross-fertilisation). Eggs with spherical slightly chalky shells are laid in damp places. Small snails emerge from eggs.


In garden - also controlled by slug pellets which contain metaldehyde.
Salt damages by osmosis.


- common or garden snail
Phylum Class Genus Species
Mollusca Gastropoda Helix aspersa

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