5250 x 3500 px | 44,5 x 29,6 cm | 17,5 x 11,7 inches | 300dpi
Data acquisizione:
2006
Altre informazioni:
The brown garden snail (Helix aspersa) (syn. Cornu aspersum) 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. 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. 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.
