When many people think of shells, they think of the ones that have been washed up on the beach, devoid of an inhabitant. Other people think of hermit crabs with their colorful painted shells, who crawl out of their shells in search of a new one.
This leaves many people wondering, can snails change shells too? The short answer is that they don’t. Keep reading to find out why.
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What Are Snails?
Snails are one of the oldest types of animals in the world with their ancestors dating back 500 million years. They are soft-bodied animals with no skeleton. They move around by sliding on mucous with their muscular foot.
Not all snails are the same, and their genetics vary between land and aquatic snails. Land snails cannot live in water, while aquatic snails need water to survive. Some aquatic snails can crawl out of the water onto land for a time and vice versa, it all depends on their breathing system. To learn more about these differences, check out this guide.
What sets snails apart from slugs and other mollusks is the shell that they carry around on their back. This provides them with protection, and they can hide within their shells whenever they are feeling threatened.
Why Do Snails Have Shells?
The reason that snails have shells is simple: it keeps them safe! Snails are soft-bodied organisms without a skeleton, so they need something to protect them from danger.
Snails and slugs are very similar organisms, but the fact is that snails have an advantage over slugs because of their shells. They are more likely to survive dangers.
If they are attacked by another creature, snails can pull their body into the shell and curl up. Most snails have an operculum at the front of their shells, attached to their foot that they use to close up their shell. This prevents other creatures from getting inside.
While some predators can break through the shell to get to the snail, the snails stand a better chance of surviving than if they had no shell at all.
Watch How Do Snails (And Other Molluscs) Create Their Shells video:
How Does A Snail Get Its Shell?
Unlike hermit crabs who have to hunt for their shells, snails are born with them. The formation of their shell begins during the gestation period.
They never worry about outgrowing their shells because the shell grows with their body.
What Shells are Made Of
So, snails are born with their shells, but how do snails make shells? How are snail shells formed?
Snails shells are made from calcium carbonate that allows for the shell to get bigger as the body grows.
Calcium carbonate is secreted from an organ called the mantle found on the outside of the shell’s body. The mantle’s purpose is specifically for making shells, so it is very important in the development of snails.
How Shells are Created
The mantle works by ensuring the calcium carbonate spreads over the surface of the snail. This give the snail full protection from its shell.
To do this, the mantle produces an electrical current that encourages calcium ions to flow where they need to go.
When a snail is first born, it is born with it’s shell, but the shell is weaker than the snail needs it to be. This first shell is called a protoconch, and it can be strengthened with lots of eating.
The protoconch forms from the snail’s mouth, continually adding new layers onto the shell. The calcium carbonate and proteins formed by the mouth will begin to harden.
As the mouth produces more of this material, the hardened material will push away from the mouth, eventually spreading to create a full shell.
As it hardens, the calcium carbonate will begin to spiral around the protoconch, creating the signature spiral shape of many snail shells. Eventually, the protoconch may break off depending on the species of snail.
Lots of Calcium
Once hatched, the baby snails first initiative is to eat lots of calcium-rich foods to strengthen its shell. The first thing they will consume is the very egg they hatched from because it is filled with calcium.
As they go throughout their lives, snails must continue to eat lots of calcium-rich foods to prevent their shells from breaking down.
Read our full guide to how snails grow their shells here.
Do Snails Change Shells?
Do snails change their shells? All of the previous information has probably led you to believe that snails can’t change their shells, and you would be right.
Their shells are physically attached to them and grow with them as their body grows. If a snail is ripped from its shell, it will die. Any snail that has been found without its shell, whether from predator or parasite, has died shortly after.
Do Snails Shed Their Shells?
A snail can never leave its shell completely. They will come out of their shell in the sense that you will see their bodies crawling around on surfaces. However, in these cases, the shell always remains firmly attached to the snail. Snails without a shell will die, so it is not possible for them to shed their shells.
In a sense, their shells may begin to “shed” when they are damaged. This is not really shedding in the sense that we think of it, and is more like degradation.
Snails need a consistent source of calcium to keep their shells healthy, so if they are deprived of calcium, their shells will develop holes. If this goes on long enough, it is possible for the snail to die.
Do Snails Outgrow Their Shells?
Snails cannot outgrow their shells. Their shells are an extension of their bodies and they will continue to grow as long as the snail does.
Can A Snail Survive A Broken Shell?
When most people think of a broken shell, they imagine something that is too difficult to be fixed. Fortunately for snails, they have an easier method of fixing their broken shells than other species, like turtles.
Turtle shells are modified bones similar to ribs. Their shells contain both nerves and blood vessels, so it can be quite dangerous for their shells to become damaged.
Fortunately for snails, they don’t have any nerves or blood vessels in their shells. In turtles, cells will try to fix the damage. For snails, calcium and protein will work to fix the shells, much as they do when they are creating them.
However, it is still quite difficult for snails to survive a shell breakage, particularly if the damage is severe. Sometimes, they need some outside help. Some aquarists will tape the shell pieces together to give the snail’s body a chance to repair the damage.
This may have you wondering, do snail shells grow back? The unfortunate answer is no.
If a snail loses its shell completely, or if a breakage is too severe, the snail will not be able to fix it. The shell will continue to break away and the snail will eventually die.
Snails need their shells to survive. They are a part of their body that they grow from birth, and without it, they are left without any protection and will die.
A shell is vitally important to a snail because it offers them invaluable protection. If they are threatened by any kind of outside source, whether it be a predator or environmental conditions, the shell will keep them safe.
If you choose to keep a snail as a pet, take good care of their shell, because it is their lifeline.