Slugs

Classification (systematic position) Source : INPN   Animal Kingdom Phylum (Phylum): Mollusca Subphylum: Gastropoda

Morphological characteristics
Gastropods with an elongated body, absence of legs (apodes), presence of a foot all along the body, 2 pairs of retractile tentacles: the first pair is olfactory and ends in the eyes and the second simply olfactory, shield behind the head and on the beginning of the back (slug) hosting the respiratory orifice (pneumostoma) on the right side; the toothed tongue forms a rasp called the radula.

Life cycle
Slugs are hermaphroditic and lay their eggs in the ground after mating. They usually lay eggs in spring and autumn. Their life cycle is shorter than snails and rarely exceeds two years.

Diet
Slugs are essentially phytophagous but they mainly consume plants at the end of their life, or young leaves that are easily degradable by their simple biochemical structure. They also decompose dead organic matter and can sometimes feed on animal remains. Some rarer species are carnivorous. They come out mainly when the environment is humid to feed.

Natural predators or regulators
Slugs are preyed upon by birds, some species of ducks, moles, and some carnivorous beetles and rove beetles.

Habitats
Slugs live in forests, meadows and gardens. They like to take shelter in areas covered with plants and mulch.

Interests in the garden
Slugs aerate the soil when they bury themselves and deposit mucus as they move around, which supplies the humus with water and the proteins necessary for plant growth. Some species degrade dead plants as well. When they are too abundant like the little gray slug ( Deroceras laeve ) in wet weather, the presence of predators can help regulate the population.

Did you know ?
Slugs bury themselves in the ground when it is too cold and move thanks to the mucus they secrete which allows them to slide.

Slugs accumulate more or less toxic substances on their backs to defend themselves from predators, which makes them difficult to eat.

The ancients used slug syrup, obtained by sprinkling sugar on a red slug, to treat coughs and rheumatism.