Why Is My Mystery Snail Floating? (The 8 Main Reasons)

Why Is My Mystery Snail Floating

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For a new snail keeper, seeing their yellow Mystery snail floating on the surface of the water tank can surely be terrifying.

However, in most cases, the snails are usually just taking time out from their usual way of movement. As more people are keeping Mystery snails as pets, it’s essential to have more information about the quirks of this species. 

Hence, this guide will answer the burning question “why is my Mystery snail floating?” to help take better care of these beautiful creatures.

Why Is My Mystery Snail Floating? 

Floating isn’t usually a sign that your mystery snails are unhappy with the water or have passed away, which is just natural behavior for them. There are some reasons that they may do it because: 

Trapped Air In Shell Or Lungs

One of the common reasons for a Mystery snail to float is the presence of trapped air in its shell or lungs. This is a common phenomenon in many species of aquatic snails, including the Mystery snails or other apple snails species.

The snails will remain floating until the trapped air has been eliminated from their lungs or shells. Even though most snails will come back down in a couple of days, some may remain floating for weeks. 

To check on your snail, gently pick it up to see if it has a closed shell. If so, put it back in the water to let the Mystery snail float without causing it any stress. 

Searching Food

mystery snail is searching food

At times, Mystery snails are a bit lazy, and rather than climbing up the sides of a tank, they may just float to the top. Hence, you may find the snails upside down munching on the food. 

Moreover, when there’s a film on the water surface, it’s common to find a floating Mystery snail as these shelled creatures love to munch on it. This film is usually made of protein from plants and food particles, so the Mystery snails get attracted. 

There’s no need to worry, as this film is completely safe for all the aquatic animals inhabiting the tank. Also, the snail may float to the top if there’s a lack of food, so you may try feeding it to see if it gets back down. 

Old Age

In a well-maintained aquarium, a Mystery snail can live for about a year. And, it’s pretty usual for an old snail to float to the water surface. It’s the easiest way for the elderly snail to get its food without needing to spend a lot of energy climbing up the tank wall.

While if you notice that it spends a lot of time floating with a bit slack body at the top of the tank, and sometimes you might even see them try to get the heck out of the tank, this might seem a bit abnormal and it may be an indication that: 

An Extreme Change In Water Parameters

Maintaining the parameters of the tank is quite necessary to minimize the stress on a Mystery snail. It’s common to find a floating snail in a dirty tank as the species is sensitive to even the slightest of changes. The snail may float to the tank’s top in an effort to relocate itself by using the water current. 

Unbalanced levels of ammonia, nitrates, or nitrites may also cause illness in the Mystery snails. Moreover, sudden change in water parameters is often felt by the snail when you have just bought it from the store. So, for the first few days, it may remain floating till it acclimatizes to the tank. 


A mystery snail can often resort to floating when it feels weak and cannot climb or move like they usually do. The most common reason behind this is stress caused by changes in the water or when the tank is dirty. 

Another reason behind floating might be injuries that aggressive tank mates like Bettas usually cause. The fishes tend to attack the long worm-like antenna of the snail and bite them off. This may trigger the snail to close up its shell and float to protect itself from further attacks. 

Copper Poisoning

Among other things, Mystery snails are also sensitive to large amounts of copper. And, as some aquarium plant fertilizers do have a large amount of copper, it can make the snail sick. So, if you use a plant fertilizer in the tank, check its copper content to consider it as a cause behind the snail’s illness. 

Due to weakness in the poisoned state, the snails often resort to floating for days or even weeks. Another sign of copper poisoning is when the snail’s body seems to come out of the shell even when it isn’t attached to any surface. 

Sadly, most cases of acute copper poisoning lead to the death of Mystery snails. 

Bullying From Other Tank Mates

You should never keep the slow-moving Mystery snails with aggressive tank mates like male Bettas. To escape the bullying of its tank mates, the snail may resort to floating for protection. 

Bullying can also happen if the snails are kept in a tank that’s too small. As Mystery snails tend to get big, a single snail requires at least a three-gallon tank. Hence, the snail may float due to the stress caused by the bullying or movement felt in an overcrowded tank. 


Sometimes the death of a Mystery snail may cause its body to float in the tank. And, in most cases, the death is also accompanied by a foul odor coming from the water. You can take the snail in your hands and check if the shell is open to ensure that it has passed away. 

However, a closed shell often indicates that the snail is alive. In such a situation, changing the tank or water may help identify the cause behind its floating. 

Final Thoughts

We hope that the guide will help you to figure out the reason behind the floating of your Mystery snail. Remember to ease out the stress of your snail without causing much disturbance to its environment. 

Besides, if there are mating pairs of snails in your tank, then the females may also float to the water’s surface to lay eggs. In that case, you’ll need to make arrangements to protect the eggs. 

Good luck!

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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