It’s a common childhood belief that slugs are simply snails that have outgrown or lost their shells.
This is not the case but, could a snail shed its shell if it wanted to?
In this article, we will find out if snails can leave their shells or actually change them.
Not only that, we will also see what would happen if a snail would damage his shell or lose it completely.
Do Snails shed their shells?
Snails start their lives with soft shells that grow along with them and harden as they age. This means the shell is fused to their body and they cannot change their shells. No species of snail is currently known to shed its shell, this includes the Garden, African Land, Apple, Mystery, Aquarium, Freshwater, Nerite and River Snails. Snails can leave their shells to search for food and mates, but they cannot live without their shells or come out of it completely.
Do snails leave their shells?
Snails will leave their shells in a sense, but their shell will always remain attached to their body. There are a lot of things that determine whether a snail will come out of its shell, one major factor is the environment. If it is too dry the snail will seal itself in its shell with a layer of mucus to prevent it from drying out. This is why you only tend to see snails outside of their shells when it is raining. They only tend to leave their shell in search of food or a mate and spend most of their life curled inside their shell. Because they retreat deep inside their shell they can often be mistaken for dead snails.
Do snails change shells?
Unlike Hermit crabs that change shells when they get too big, snails cannot change their shell. The shell is a part of the snail which they are born with and it grows alongside them, meaning they never outgrow their shells. Snails grow and maintain their shells themselves and if they changed shell they would lose valuable protection. They would not be able to repair or maintain a new shell as it would not be fused to its body.
Can a snail live without a shell, what happens when it loses its shell?
A snail cannot live without its shell, the shell protects it from predators and environmental conditions. If a snail is outside its shell then it is because the shell has been destroyed, although some scientists have theorized that parasites may make their way inside the shell and force the snail out. If a snail loses its shell it will sadly die shortly after, no snails have been known to survive for any more than a short amount of time without their shell.
Do snails die when their shell breaks?
The biggest factor when concerning this question is the severity of the breakage. Snails are able to repair minor breakages to their own shells. Some snail owners will help this process by using products, such as tape, to temporarily hold the shell together whilst the snail fixes it naturally. However, most breakages cannot be repaired by snails and the shell will eventually crumble away. The breaking of a shell would not kill a snail directly but without a shell a snail cannot survive.
Comparison Between Different Snails
You might be wondering if whether a snail can change its shell or not is dependent on the species. Below I’ve provided some common snails and their descriptions so we can look into if they can change or shed their shell.
Do Garden Snails shed and change their shells
The Garden Snail is a small brown snail which, as the name suggests, you may find in your garden. Their shell has a rough texture and has a diameter of 40mm. It is a common myth that garden snails can shed and change shells, usually told to you to make you feel less bad about accidentally stepping on one. However, these snails cannot shed or change their shells.
Do African Land Snails shed and change their shells
The African Land Snail is a large species of snail with a brownish-yellow conical shell. African Land Snails do not change their shell and are unable to detach from them. Sometimes their shells can become flaky which can be mistaken for shedding behaviour, but it actually means the shell is damaged, likely due to low levels of calcium.
Do Mystery Snails shed and change their shells
Mystery Snails are fresh-water snails commonly kept in aquariums to help control algae. Their shells can come in blue, black gold and white. A lot of aquarists have noted that they have seen what they think is their snail shedding its shell. In actuality, it is common for Mystery Snails to get growth lines, these are white flaky lines across the shell. They cannot shed or change their shell.
Do Apple Snails shed and change their shells
Apple Snails are a family of snails which encompasses the Mystery Snails. Apple Snails have the ability to grow their shells really quickly compared to other snails. Because of this they are good at repairing their shells but they do not shed or change them.
Do Aquarium Snails shed and change their shells
Aquarium Snails are tiny snails considered pests by aquarists. A long thin-cone shell is its definable feature. They can be introduced to the tank via plants and thrive well and produce asexually. They do not change or shed their shells but their long cone shell does grow quickly in comparison to other snails, sometimes making it seem like they have changed to a bigger shell.
Do Freshwater Snails change and shed their shells
Freshwater Snails encompass a large family of snails, most being small gastropods with brown spherical shells. Freshwater Snails commonly stay retreated into their shell which may be mistaken for them shedding or changing shells as it is difficult to see their fleshy body. However, they do not change or shed shells.
Do Nerite Snails change and shed their shells
Nerite Snails are arguably the most popular snail for aquarists and come in two main types, Zebra Nerites and Tiger Nerites. A lot of aquarium keepers have noted their Nerite Snails changing in colour, it is possible this change in colour could be mistaken for shell shedding. They do not however change or shed shells and usually shells changing colour is a sign of calcium deficiency. Others have suggested it may also be related to old age.
Do River Snails change and shed their shells
The common River Snail is a wide-spread species of snail, it has a yellow-green shell with spiralling brown stripes. River Snails, like all other snails, cannot shed or change its shell. However, the River Snail’s shell can deteriorate quite easily and it requires a large amount of oxygen in the water to remain healthy.
Why do snails lose their shell?
Now that we know snails don’t shed or change their shells, lets look at why one may be without its shell. The most common reason for this is that their shell has been broken. This usually occurs after it has been stepped on by a person or if their shell has been damaged beyond repair by a predator. The loss of a snail’s shell can also be quite a long process. Snails with problems, such as calcium deficiency, will often lose their shell and it will slowly flake away. This is because they do not have the calcium levels and energy to repair it. If a snail has lost its shell it is never an intentional act on the snail’s part.
Why are there empty snail shells
If snails don’t shed or change their shells, then why is it so common to see an empty snail shell on the ground? The main reason is that the body of the snail will either be eaten or it will decompose once it has died. Snails have a fleshy body that will rot away, however the shell does not rot and can become fossilised. It is for this reason we have a lot of information on prehistoric gastropods. If you have come across a small area with a large number of empty shells, it is possible a predator has taken the snails to its nest, consumed them and then dropped their shells in a small surrounding space.
Related topics
Are snails born with shells?
Yes, snails are born with soft and transparent shells which grow and harden as they age.
Can a snail become a slug?
Slugs and snails are different species and a snail cannot become a slug. However it is very possible that they evolved from the same ancestor.
Why did my snail leave its shell?
I’m sorry to say that if you snail has left its shell it is either close to death or has died. It has been theorised that parasites can force snails out of their shell but snails cannot survive without their shell and should not be able to shed it.
Where do snail shells come from?
Snails are born with their shells and they need a calcium rich diet to form a healthy shell. Snails often eat the egg which it hatched from; the shell of this egg has the necessary nutrients to help the snail start forming its harder shell.