Additionally it tastes really disgusting, as the German poet Hermann Lönsĭiscovered in a particularly remarkable self-inflicted experiment.īesides, slugs, when attacked, will contract their body and so make it veryĪ slug ( Arionidae) descends by a slime thread. Slugs' slime is specially sticky and hygroscopic, meaning it draws water rather than releasing it. The external protection of a slug mainly happens by its mucus or slime. Snails' shells serve as a means of protection against desiccation and against enemies, though there are many animals that can easily destroy a snail's shell. Testacellidae are only distantly related to theĭaudebardiinae, though they also live and hunt underground.Ĭomparing different slug groups arises quickly the question, how those shell-less snails could survive, without the protection of a shell.
Testacellidae family during their evolution. A similar thing happened to snails of the Which, as a result, leaves theĭaudebardiinae with only the meagre rest of a glassy shell carried at the tip of the tail. Life underground made necessary the reduction of the cumbersome shell. One of them, the Daudebardias ( Daudebardiinae), for example, are a family of predator snails living underground and hunting earthworms, that are caught with the radula and swallowed whole. Slugs from theĪrionidae family, in contrary, only have some calcareous grains left over from their ancestors' shells.Ī strong shell reduction has also happened during the evolution of different predatory snail groups. Both have got a rudimentary shell below the mantle shield. This state may be found among slugs of the Some glass snail species have a shell, whose spire is diminutive, the last whorl, in contrary oversize and widened.Ī further reduction of the shell following that tendency would be the mantle fold overgrowing all of the further diminished shell. One is common to all of them: A large mantle flap covers the shell spire from the front. There are different grades of shell reduction among the species of that family. Glass snails ( Vitrinidae), for example, are called that way, because their shell has only a thin wall translucent like glass. Today, a gradual reduction of the shell may be seen among several contemporary snail families. What is the advantage, that made loosing protection by their shell a feasible option for those gastropods? In the sea you might find the colourful nudibranchs – them as well survive without a shell.Īfter rain you may often meet the large black slugs ( Arion ater), many of their smaller relatives crawling around in the bushes, and, alas, also in the gardens. But the reduction of an exterior shell not only happens among land snails.
Snails without a shell are generally referred to as slugs. īlack keel back slug ( Limax cinereoniger, NEW: Different kinds of slugs in pictures: TheĪ slug ( Arion rufus ?) in a forest. Slugs - Life (Almost) Without A Shell Slugs - Life (Almost) Without A Shell
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