Snails are all molluscs, regardless of size (some measure as little as 2 millimeters) or shape. 40% of molluscs being land snails, some snails however are aquatic species, more freshwater: Basommatophora such as snails or planorbs, often called "cleaner snails" by aquarium enthusiasts.
The difference between snail and slug is not always obvious. Thus, some slugs such as testacelles have a rudimentary but clearly visible shell, while snails of the Vitrinidae family called glass snails (glass snail) by English speakers, including Eucobresia nivalis ou semilimax semilimax, for example, have only a fragile and incomplete shell into which the animal cannot generally withdraw completely. Intermediates, semi-slugs are terrestrial gastropods whose shell is too small for the adult animal to fully fit into, but this shell is not vestigial.
Most snails are phytophagous, although a few species are omnivorous, zoophagous or detritivorous.
The most discreet species remain very poorly known. There are many species, many of which are probably still unknown to science, scientists having described in 2004 nearly 80 species out of the 000 listed molluscs (there could be 200 to 000 million according to biologist Benoît Fontaine) , including 5 in France. In Slovakia alone, specialists have identified fifty-three aquatic (freshwater) and one hundred and seventy-five terrestrial species, a total of two hundred and twenty-eight species, much more than in the Netherlands where one hundred and sixty - nine species have nevertheless been identified (fifty-two in fresh water and one hundred and seventeen on land).
It is common to find endemic species on islands or in very isolated environments for a long time.
In France four species are usually eaten under the name of snail:
– Helix aspersa: The gray squirrel (Helix aspersa aspersa), with more diverse and often local recipes, a size of 26 to 30 mm for an adult weight of 7 to 15 g. Present in the Mediterranean countries (Europe and North Africa) and the French Atlantic coast.
It has a brownish shell, coiled with tawny grey, with a hemmed edge; it is found in other ecosystems than the previous one. Its firm flesh is fine and tasty.
– Gros-gris (Helix aspersa maxima), size of 40 to 45 mm for an adult weight of 20 to 30 g, present in North Africa.
– The real Burgundy snail (helix pomatia), traditionally prepared in the shell, with parsley butter. Size from 40 to 55 mm for an adult weight of 25 to 45 g.
It is also called "vine snail" or "big white", it has a tawny yellow shell streaked with brown, with a barely hemmed edge. Its growth lasts from 2 to 3 years and its breeding is random.
Its natural geographic distribution is Central Europe.
No so-called Burgundy snails are bred in France: all those found on the stalls are snails imported from Eastern Europe. The name “Burgundy snail” comes from an anecdote dating from the end of the XNUMXth century: a Burgundian innkeeper received the Tsar of Russia somewhat by chance when he had nothing left to serve, only bread. He then decides to go pick up snails in his garden and prepare them with parsley. The Tsar was amazed by the quality of the recipe and back in Russia, he asked his cooks to cook “Burgundy snails”.
- Helix lucorum, imported from the Balkans or Turkey, often wrongly sold as a Burgundy snail.
The achatines: The snails "achatines", large (10 to 15 cm) less fine, are sold canned; they come from China, Indonesia or Africa.
As French species are becoming increasingly rare, imports have increased considerably.
The period for collecting snails, as well as their sale as live animals, is regulated, in particular for the minimum legal size. Priority is given to picking up so-called “bordered” snails, ie those with a shell whose edge has a slight upturn, because they are adults and their shell is also more solid.
Farms of squirrel, just profitable, have developed in recent years in France, in Charente-Maritime. Prehistoric man ate snails.