Breathtaking tricks: How do snails really breathe?

Snails are slow-moving, carry their homes on their backs, and are quite common in gardens worldwide. But beyond these everyday facts, there is a lot more to these unique creatures. Take, for instance, their breathing process. How do they breathe, you may wonder? Do they have a nose? Well, let’s take a look under the shell and find out!

How do most animals breathe?

Before we understand how snails breathe, let’s review how breathing works in general. Breathing involves taking in oxygen from the air and releasing carbon dioxide and water vapor. In many animals, this is done with the help of lungs . Lungs are like bags filled with tiny passages and air sacs. When an animal breathes in, oxygen fills these sacs. The oxygen then moves into the blood, which carries it around the body. When the animal breathes out, it gets rid of carbon dioxide, a waste gas produced in the body.

How do snails breathe?

Snails do things a little differently. And even within snails there is a difference in how they breathe. While they all need oxygen to live and do produce carbon dioxide as waste, they don’t all have lungs. Some snails, especially those living in water, breathe using gills . Gills are feather-like organs that take oxygen from the water. This might seem odd to us, but for a snail, it’s as natural as using lungs is for us.

On the other hand, land snails and some freshwater snails do have a type of lung. It’s called a pallial lung , located in the mantle cavity , a special part of a snail’s body. It’s not like our lungs. It’s more like a space inside their bodies where air can come in. Oxygen then gets into their blood from this space. And just like us, they breathe out carbon dioxide.

How do aquatic snails breathe?

So we know that water snails and land snails breathe differently. But there’s more to the story. A water snail has a special siphon, kind of like a tiny snorkel. They can stretch this out above the water’s surface to take in air if needed. Isn’t that smart?

Land snails, on the other hand, can’t stay submerged in water for too long. They need air to breathe. Some land snails have a neat trick, though. When the weather is too hot or dry, they can go into a deep sleep, called aestivation , and seal their shells with a layer of mucus. This keeps them safe and moist, and they use up less oxygen. When the conditions are right again, they “wake up” and continue their slow, steady journey.

Whether they are in water or on land, snails have unique and adaptable ways to breathe. Some use gills, others use a type of lung, and some even have snorkels. For an animal so tiny, snails have quite a fair share of neat tricks for breathing.

Can snails breathe underwater?

Snails can breathe underwater, but differently from fish. Most aquatic snails with gills will extract oxygen directly from water and will be able to breathe underwater. Land snails breathe through a lung-like breathing pore called a pneumostome and cannot survive underwater for extended periods. Aquatic snails can remain submerged indefinitely, while land snails will drown if completely underwater for too long.

Glossary

Lungs: Organs in an animal’s body where most of the processes of respiration occur.

Gills: Respiratory organ found in many aquatic organisms that extracts oxygen from water and excretes carbon dioxide.

Pallial Lung: A lung present in certain mollusks, used for respiration and formed from a mantle cavity.

Mantle Cavity: The cavity which houses certain internal organs in mollusks and brachiopods.

Aestivation: Long-term dormancy or state of reduced metabolic activity that snails and some other animals enter in response to high temperatures or dry conditions.