Anyone who has ever seen a snail knows they come with a shell on their back. These shells are beautiful to look at, and many people like to collect them because they come in so many varieties.
Many people who have had hermit crabs as pets also know that they need to purchase extra shells for their crab to grow into. Is this the same for snails?
Do snails grow out of their shells? Do snails leave their shells? Why would they want to?
What Are Snails?
Snails are gastropods, soft-bodied animals without any kind of skeleton. They are one of the oldest and most diverse species on the planet, dating back 500 million years to the Cambrian period. They can be found all over the world on land and in water.
The main thing that sets snails apart from other snails is the way they breathe. Most snails are equipped with a lung to breathe dry air, but of course, most aquatic snails will have gills instead. However, there are some snails that have a lung and gills so they can breathe both on land and in water. To learn more about this interesting biological process, read our full guide on how snails breath here.
What sets snails apart from other gastropods is the protective shell they carry on their back, keeping them safe from everyday dangers. So, is it possible for snails to leave their shells? If they could, would they even want to?
Why Snails Have Shells
The reason that snails have shells is quite simple. They are soft-bodied animals without any skeleton. Shells keep them safe. When they feel threatened by predators or environmental instabilities, they can hide inside their shells for protection.
Most snails have a “door” covering the aperture of their shell called an operculum. They can open and close this door at will depending on whether they wish to go inside their shell or come out of it. The operculum can prevent predators from entering the shell and eating the snail.
It can also prevent a snail from drowning or drying out, depending on whether the snail lives on land or in water.
Where Do Snails Get Their Shells?
Snail shells come in so many varieties of shapes and colors, you may be wondering, where do snails shells come from?
How do snails find their shells? Quick fact — they don’t! The shells “find” them.
Well then, do snails make their own shells?
Unlike hermit crabs who must steal their shells from other organisms (like snails), snails are born with their shells. Their shell begins growing while the snail is in the gestation period, still in their egg. They are born with a soft shell that is not completely formed, and the shell keeps growing as the snail does.
Snails never need to worry about outgrowing their shells either because the shells grow right along with the snail.
To learn more about the fascinating process of shell creation, check out our full guide here.
Do Snails Need New Shells?
Is there ever a reason why a snail would need a new shell? Do snails lose their shells?
Snails never need new shells, and in fact, it’s not possible for them to get a new shell. If a snail’s shell is damaged so badly that they would be in need of a new one, they are going to die. While it is possible for snails to repair a damaged shell, if it is too far gone, they will eventually die.
Do Snails Leave Their Shells?
So, can snails come out of their shells? The answer to that is also no.
Just as a snail can never get a new shell, they also can’t leave their shell. The reason that hermit crabs can leave their shells is because the shells don’t actually belong to them. Hermit crabs steal shells from other organisms, like snails, to survive. As the hermit crab grows, they have to keep changing shells to find one that is big enough for them.
Snails don’t have to worry about this shell switching because they are born with their shells and they are a part of them. In fact, snail’s shells are attached to their bodies, so it is damaging and fatal for a snail to be taken from its shell.
Why Do Snails Leave Their Shells?
It is not possible for snails to leave their shells willingly. Of course, they can and will come out of their shells to explore, but they only do so partly. While they explore, the shell remains firmly planted on the snail’s back.
The only time a snail would leave its shell completely is if it’s forced to. Usually this happens because of a predator, whether it be a hermit crab evicting them to steal their shell, or an animal wishing to eat them. In these situations, the snail is likely going to be eaten by whatever it is that ripped them from their shell. Even if they aren’t eaten, they won’t survive without their shell.
Can Snails Live Without Shells?
Unfortunately, snails cannot survive without a shell. The shell is attached to the snail’s body, so their shell being ripped from them is quiet painful and damaging.
Not only will their bodies be injured, but they cannot grow their shell back. This leaves them exposed to any threats. Even if a snail survives the initial deshelling, they will not survive for long.
Do Snails Leave Their Shells When They Die?
Technically, snails do leave their shells when they die, although this is not by choice. When a snail is about to die, it will not willingly crawl out of its shell. Instead, the snail will hide itself inside the shell and close off its operculum until it passes.
If the snail is degrading inside your aquarium before you realize it’s dead, however, the body will eventually leave the shell. The muscles of the snail break down and are no longer able to hold the body in the shell. A very easy way to tell if your snail is dead is simply by picking them up.
If they stay tucked inside their shell with their operculum closed, then they are alive. If you pick them up and their body falls out of the shell, hanging limply, then the snail is dead.
If a dead snail is never removed from the aquarium, the body will eventually degrade enough that the operculum will release from the shell and fall off completely. This will allow the degrading body to also come out of the shell and degrade further into the water column.
The shell is the most important part of a snail’s body. A shell offers the snail protection both from predators and from the outside environment. Not only does the shell offer protection, but the shell is part of the snail. Without it, the snail cannot survive.