Is Your Mystery Snail Dead Or Dying: 6 Ways To Tell

Last Updated on 2023-11-08

Mystery snails, or apple snails, are popular aquarium pets. They can unexpectedly fall ill or die, making it hard to identify a dead snail. Dead snails have a strong odor, so it’s important to know what to do with them.

So, I wrote this guide to give you all the information you need about dead snails, so you can keep your aquarium healthy and thriving!

  • Mystery snails, also known as apple snails, can pose challenges when trying to determine if they are ill or deceased.
  • Factors like sleep, cold, hibernation, water quality, and illness can make them appear inactive.
  • To identify a dead snail, look for a bad odor, smaller size, and shell changes.
  • Dead snails should be promptly removed to maintain water quality.

Why Is My Mystery Snail Not Moving?

Mystery snails are low-maintenance and visually appealing pets. But if you find one not moving, don’t panic. An inactive snail may not necessarily be dead. There could be many reasons behind its stillness. Want to know more? Keep reading!

It’s Asleep

Everyone, even humans, needs to rest their weary bodies from time to time, and sleep is the perfect way to do just that. After a long day of foraging and exploring, mystery snails enjoy a good nap. In its tank, a mystery snail may spend up to 30 hours a day eating and moving around, followed by 13 hours of sleep.

Feeling Cold

It turns out that mystery snails are quite delicate and can’t handle the cold. In extreme cold, a mystery snail will retreat into its shell, shutting its trap door behind it until the temperature rises again. Keep the water in the tank at a constant temperature of 20 to 28 degrees Celsius.


Due to the optimal circumstances in an aquarium, snails rarely hibernate. In times of severe weather or scarcity of food, such as winter, many animals enter a state of hibernation to preserve energy. A mystery snail that has been well-fed will not hibernate, but it will if its food supply is suddenly cut off.

Water Pollution Caused by Chemicals

When the water quality drops, the mystery snails hide away inside their shells. It is crucial to check for the presence of any chemicals because some compounds are hazardous to mystery snails. Ammonia, copper, and nitrate should not be present in tank water. Also, the pH should be kept at a steady 6.5 to 7.5.

An Abusive Environment for a Mystery Snail

Unlike some other species of snail, mystery snails are completely docile and won’t harm anyone or anything in their aquarium. However, they are defenseless due to their lack of a robust protection system. To be safe, they must retreat into their shells once more.

Your Mystery Snail Is Ill

Most animals, when sick, will rest until they feel better. Snails are the same as any other animal in that they retreat into their shells and close the escape hatch when they need to rest.

New Surroundings

A new snail can stop moving and hide for a few days to let its body adjust to its new environment.

Dead Mystery Snail

How Do You Know If Your Mystery Snail Is Dying

As small as they are, mystery snails can be surprisingly resilient creatures. But even the hardiest snail will eventually succumb to old age or medical issues. So how do you know if your little mollusk friend is on its way out? 

  • Take note of its movement.  A dying snail may not move much at all or appear sluggish in its movements. Also, if your snail is upside down or floating lethargically at the top of the tank, it’s time to take action. 
  • Make sure to check for any visible wounds or discoloration on its shell and body. These may indicate a bacterial infection.
  • Observe its eating habits. A healthy snail will be regularly grazing on food and maintaining its calcium levels through the consumption of cuttlebone, while a dying snail may no longer have an appetite or even reject food entirely. 

By keeping an eye out for these warning signs, you can catch any problems early and give your beloved mystery snail the best chance at a long and happy life.

IndicatorSigns of a Dead Mystery Snail
SmellStrong, unpleasant odor
SizeSmaller and lighter in weight
ShellEmpty or easy to remove
TrapdoorClosed trapdoor indicates life
LightNo reaction to artificial light
RelocationNo response to touch

How To Tell If Your Mystery Snail Is Dead

Your mystery snail’s smell, appearance, and behavior will all indicate whether or not it is still alive. Most decaying snails have a strong odor. Once a mystery snail dies, it often shrinks and loses its shell. In that instance, the shell’s weight will be reduced and there will be no reaction to the environment. 

You can find out if your mystery snail is still alive or not by checking the following:


This is the most noticeable indicator. The dead snail stinks. If your mystery snail isn’t doing anything, you should take it out of the tank. You can learn a lot just by smelling what’s going on.


Once a snail dies, it typically becomes much smaller than it was before. In addition, they feel lighter. If you pull a snail out of the water and it doesn’t feel as heavy or seem as big as you recall, it might be dead.


Check out what’s inside the snail’s shell. If a snail’s shell is empty, it’s safe to assume the animal has recently died. Many times, the shell will come off when you lift a dead snail because the snail has shrunk so much that it can’t hold on to its shell.


Carefully inspect the snail until you locate the hiding place. If a snail’s shell is open, it has likely already been eaten. The trapdoor can be opened by pulling on it if it is closed. It’s a good sign if the snail gives you a little pushback to see if it’s alive.


Some snails may be coaxed into action by the use of artificial light. If that doesn’t happen, try exposing the snail to light. The thickness of the shell determines whether or not the snail’s heartbeat may be seen. To put it another way, a snail that has already died does not have a beating heart.


Many times, simply relocating a dormant snail might get it moving again. If you touch a real snail, it will probably try to hide under its shell. A snail that has already died will not react to these.

How To Tell If Mystery Snail Eggs Are Dead

Mystery snails can only reproduce by mating with a mate of the same gender. Approximately two to three weeks after mating, the female mystery snail will lay her eggs. An egg that has been fertilized and is in the process of hatching will expand and become darker as it develops. Dark patches will appear on the day they hatch. 

In contrast, the following characteristics distinguish eggs that are dead or otherwise infertile:

  • Infertile eggs retain their small size (the same as when they were laid) and uniform dark color but no dark patches after two to three weeks.
  • Smell the eggs to see whether they have a bad odor. If there is a powerful or unpleasant smell coming from the eggs, they are likely dead.
  • A wet cloth is a good way to inspect for stains. Fertile eggs won’t leave any color on the damp cloth, but infertile ones will leave a reddish or pinkish stain.
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How Long Can Snails Go Without Moving?

Did you know that snails can hibernate for over three years without moving? It’s true! Although, if you have an aquarium snail, they usually just sleep or stay inactive for about two weeks. There are a few reasons why they might stay still for that long.

For example, during transportation, snails usually don’t move for around three to four days. And when you introduce new Nerite snails to a new environment, they may not move at all until they get used to their surroundings.

Do Mystery Snails Float When They Are Dead?

Those who have kept snails for any duration of time know that they occasionally develop the ability to float. When it’s dead, a mystery snail will float at the top of the tank. If the snail has air-filled lungs, when the water conditions are improper, or if there is film in the tank, mystery snails may float to the top.

If your mystery snail floats often, there’s an easy cure we’ll explain below. Most likely, your mystery snail is floating for the following reasons:

Too Much Air In The Lungs

Mystery snails are a bit notorious and careless when it comes to closing their lungs. Thus, they mimic the functioning of a balloon by trapping a small amount of air inside. When the air becomes trapped, they float to the surface of the water and begin to rise.

A Tank Full Of Film

When there isn’t enough movement on the water’s surface, or when some innocuous bacteria settle to the top, a milky film can form in freshwater aquariums. Because of these two factors, plant proteins and food scraps can bond and form a film.

The inhabitants of your aquariums are safe from this film, and in fact, certain snails, like the mystery snail, like nibbling on it. Because of this, they ascend to the tank’s ceiling, where they float face-down while chowing down on the film.

Low-Quality Water

A mystery snail may float if it is unhappy with the tank’s water. As a matter of survival, they can also try to get out of their shell. Mystery snails are sensitive to nitrates, nitrites, and ammonia in aquarium water. With just a strip, you can determine where the parameters stand.

It will take some careful observation to figure out why your mystery snail keeps popping up on the tank’s surface. Knowing the root cause of your mystery snail’s floating behavior will direct your next steps. Before doing anything else, you should pick up the snail and examine its shell to see if it is open or closed. If it is closed tightly, you know it is not dead.

Watch this video by Aquarium Store Depot about how you can tell if your snail is dead:

What To Do With Dead Mystery Snail?

Mystery snails are, in fact, permanently attached to their shells, contrary to popular belief. You can tell it is dead if the body is hanging out of the shell or is no longer in the shell and is not moving. When this happens, to avoid the possible spread of disease in your tank, you should get rid of it as quickly as possible.

Take Out The Snail

Dead snails should be removed from the water as soon as possible. If you leave a dead snail in the aquarium, it will degrade the water quality and maybe kill the other inhabitants.

Refrigerate or Freeze It

It’s not a good idea to dispose of the deceased snail in the trash once you’ve taken it out of the aquarium due to its bad smell. Put the snail in a plastic bag and seal it. Put the snail in a bag and freeze it to lessen the odor. Take the snail out of the freezer as soon as you’re ready to toss it out the trash.

Get That Tank Cleaned!

If you want to lessen the effects of the dead snail, you should clean the tank and change some of the water.

Keep  the Shell

Unlike the other steps, this one is more about honoring your dead snail. The actual body can be discarded while you preserve the shell as a souvenir.

Here’s how to remove a snail from its shell:

  • The snail should be dropped into a pot of boiling water as soon as possible after it has been killed. The maximum recommended boiling time is 3–5 minutes.
  • Put it in the fridge or somewhere cool to chill down. It shouldn’t be washed in cold water.
  • Just shake it up really well. At this point, the interior is soft enough to be easily extracted. Perform this task in a sink for optimal results. There is no need for any of its remnants to pollute your space.
  • Once the body parts have been removed, they can be sealed in a plastic bag, store it in the freezer, and put it in the garbage when you’re ready to toss your trash out of your house.

Why Did My Mystery Snail Die?

What is killing your mystery snails? This problem is reported by aquarists from all over the world who are attempting to care for mystery snails. We’ll go over the possible causes of your mystery snail’s death one by one below.

There Is Not Enough Food for Them

A common myth is that mystery snails need nothing more than the algae in an aquarium to survive. They aren’t getting enough to eat since there aren’t enough algae growing in your aquarium. As soon as they finish cleaning up in a couple of days, they start to starve to death. It’s essential to give them more food.

Toxins and Other Chemicals Can Have Devastating Effects on Them

Chemicals containing copper, in particular, have a profound effect on snails (which many do). If at all possible, do research on the chemicals before using them.

Poor pH

Because of their extreme sensitivities, Mystery snails are vulnerable to changes in pH. Most of the time, if their tank’s pH isn’t between 6.5 and 7.5, they will become stressed, stop eating or even die.

Your Snails Are Coming From a Bad Source

Most likely, this is the main cause of Mystery snail deaths. It shouldn’t be a surprise that many local pet stores mistreat the animals they sell. Snails are equally as susceptible to this (just like any other creature).

It’s Being Eaten

While this is extremely unusual, it does occur. Sometimes larger fish will attack mystery snails, and the next morning, you’ll just find the shell. Another possibility is that they are hurt and you don’t see it in time, leading to their internal decomposition and eventual death.

(Click here if you want to know more about whether a snail is dead, what to look for and if their sleeping.)

How Long Can A Mystery Snail Live Out Of Water?

One of the most well-liked algae-eating animals is the mystery snail. For this reason, they are an essential tool for aquarists in the fight against algae. In addition, they are available in a wide range of colors, from ivory and gold to blue and black, making them a fantastic option for sprucing up the look of any aquarium. Plus, they’re an exceptionally peaceful species overall.

Many aquarium keepers with mystery snails want to know how long the creatures can survive without water. It has been found that the mystery snail can go five days without water. But the size and age of the snail make the biggest difference.

A larger snail’s ability to go without water increases proportionally with its size. A snail’s life depends on its ability to enter a hibernation-like state while it is out of the water.

What Happens When a Mystery Snail Dies?

The average lifespan of a Mystery Snail has been calculated to be around one year. If the snail is fortunate and the water conditions are favorable, it may live for a much longer time. The dead body of a Mystery Snail can be easily identified, much like that of any other freshwater snail. Observing the snail’s actions can give useful insight. 

Remove the Mystery Snail with a fish net carefully. If it floats in the water for a longer period of time than usual, if it remains immobile on the tank bottom, if it is upside down, or if its body has grown too large for its shell. Dead snails have an incredibly strong, foul-smelling odor. A snail with a foul odor coming from its body is likely dead and should be removed from the aquarium. 

Immediate removal of a deceased Mystery Snail is recommended to prevent further damage to the tank’s water quality, such as an increase in Ammonia levels. When a snail decays, it produces a lot of ammonia, which feeds the tank’s nitrogen cycle and kills out the other organisms.

How To Prevent Mystery Snails From Dying

Pomacea diffusa, sometimes known as the “mystery snail,” is a popular species of freshwater snail that can be bred and kept as a pet. Mystery snails have an average lifespan of two to three years when kept in ideal conditions. You can keep mystery snails from dying with the right tank setup, the careful introduction of the snails, and regular maintenance.

There are a few things tank owners can do to keep their Mystery Snails healthy.

Mystery Snail Tank/Water Requirements for Optimal Health

Mystery Snails may be tiny, but they still require some room to move around. These beautiful invertebrates can ‘vacuum’ up aquarium dirt remarkably quickly, at least for a snail. Each snail needs a tank that’s at least 5 gallons in capacity.

Water is the first step in taking care of a snail. They do best in a tank with temperatures between 68 and 84 degrees Fahrenheit. Water hardness (kH) should be between 12 and 18, and pH should be in the 7.6 to 8.4 range. When the water’s pH is low or it’s soft, the snails’ shells might become brittle, flimsy, or even crack.

Mystery Snail Tank Mates

Some fish species are more likely to assault and hurt the snails despite their peaceful nature. Before adding a new fish to the tank, it’s important to exercise caution and conduct some study to make sure it won’t harm the snails. Larger nipping fish, such as goldfish or cichlids, should be kept away from the snails since they may be enticed to nibble on the tentacles.

Eating Habits of a Snail

Most of a Mystery Snail’s day is spent cleaning the tank by ingesting garbage, leftover food, and biofilm. Snails are voracious consumers and recyclers, but they can’t survive on what’s at the tank’s bottom. Fresh spinach, collard greens, broccoli or cauliflower leaves, peeled zucchini and cucumber, kale, cabbage, and other high-calcium vegetables are all acceptable food for mystery snails.

Shells Need Calcium for Strength and Health

Calcium is an essential mineral for Mystery Snails to obtain from the food they eat so that their shells can develop properly. Adding an aquarium-quality cuttlebone is a simple and popular choice for supplying calcium to fish.

So that it sinks to the bottom of the tank, many people like to boil the cuttlebone first. It is safe to consume raw cuttlebone, and it will float for about 10 days before sinking on its own.

Keep Snail Tanks Safe

Mystery Snail care involves making sure the tank is secure. Snails can escape from an inadequately sealed aquarium, thus it’s important that the top fits snugly over the tank. Snails can live above the water for a while, but they will eventually dry out and die if they get out of the tank.

And to ensure the well-being of all your aquarium inhabitants, it is essential to pair together compatible fish species. Some fish species are so aggressive that they can kill a snail just by nibbling on its feelers.

Why Is My Mystery Snail Not Moving When I Poke It?

If a mystery snail stops moving, don’t assume it’s dead; instead, study it to find out any other possible reasons. This could be due to the snail being asleep, feeling cold, avoiding unfavorable water conditions in the tank, or avoiding potentially antagonistic tank mates.

What To Do With Dead Mystery Snail If You Want To Keep The Shell?

When the snail is dead, immediately drop it into boiling water. Boiling for 3–5 minutes is suggested. Put it in the fridge to chill. Not cold water. Shake thoroughly. Once the bodily pieces are removed throw them away and keep the shell.

How Do You Dispose of A Dead Mystery Snail?

If the dead snail hasn’t been eaten by other inhabitants, remove it. Use gloves or a soft spatula to remove the dead snail. Put it in a Ziploc bag and refrigerate. This slows decomposition and prevents odor. Throw it out on trash day.


Mystery Snails are interesting creatures and make great pets for people who want to learn about them. If you have a mystery snail and it is not moving, there are ways that you can determine if it is dead or just inactive. If your mystery snail eggs are not hatching, there may be something wrong with the eggs themselves and you can tell by looking at them whether they are dead or not. As a last note, there are a few options for getting rid of a dead mystery snail.


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