This is an apple snail because of its color, form, and size.  It is thought that it got its name because the aquarium market did not know what type of snail it was so they just called it a mystery snail and the name stuck. 

 There are several ways in which you can tell if your mystery snail is dead or alive, which will be covered in this article.

How to Tell if a Mystery Snail is Dead or Alive

With snails of any type, the cooler the water, the more they slow down but when the water is warmer, they will become more active.  Here are several ways in which you can tell if your mystery snail is dead or alive.

  • Smell Test:  This is the real test to tell if your snail is dead or alive.  If they are dead, they will reek but sometimes they may not smell for a few days.
  • Retracting:  If you pick the snail up, they should retract back into their shell but all of them may not act that way.  
  • Fall out of Their Shell:  Sometimes after you notice a dead smell and if you pick it up and give it a gentle shake, they will fall out of the shell.  Make sure if you try this test that you do it over a container so you do not have a smelly mess to clean up.
  • Trapdoor:  You can give the trapdoor a tiny tug to see if it stays shut.  Do not tug hard because you can hurt it.  It is not dead if you feel any resistance.
  • Hold it up to the Light:  If they are an apple, or mystery, snail, they will have a trapdoor so if the door is shut tight you can hold it up against a light bulb so you can see through the shell.  If it is dead, the snail inside has shrunk so there is more empty shell when compared to the body.
  • Respond to Touch:  If the snail has still not responded you can tickle its stomach and if it is alive, you will get an immediate response.
  • Tap on the Shell: Gently tap on the shell several times to see if you get a response.
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Sometimes they will withdraw into their shells for a couple of days, which is normal.  When a snail is out of their shell and not responsive, then they are most likely dead.  You will need to remove them as quickly as you can from the aquarium because the decomposition will pollute the water in the aquarium very quickly.

yellow mystery snails

What to Do When You Are Not Sure if the Snail is Dead or Alive

  • Check water parameters:  A snail is susceptible to sudden nitrate and ammonia build up in the water and sudden pH changes.
  • Remove From Aquarium:  If your snail has been inactive for a while you should remove them from the aquarium and put them in a bowl or jar with some of the aquarium water if the parameters are good.  When you do this, make sure that you change the water the snail is in a few times during the day.  This way, if the snail is dead or dies, it will not pollute your aquarium.
  • Help the Snail Strengthen its Shell:  You can do this by making sure that you are providing your snail with enough calcium.  One way to do this is to use cuttlebone but if you do, you will need to briefly boil it.  When you boil it, it will sink to the bottom of the aquarium.  If you do not boil it, it will float like Styrofoam for several weeks.  You can also use fish feeder vacation blocks.  The snails will eat them to get at the fish food inside of them.
  • Sick:  If you think that your snail is sick you can try an air bath.  Dampen a towel to make a nest on a surface that is waterproof and put the snail in the middle and wait.  You want to see if it comes out of its shell.  It is safe to wait for thirty minutes to see if it comes out.  When it does, let them sit for 20 minutes, and then you can put them back into the aquarium.  This is good if your snail should have a fungal issue on their foot.  
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What Happens When a Snail Dies?

Contrary to what some think, a snail is fused to their shells.  They do not crawl out to die but after they die, their body may fall out of their shell. 

If you notice that the body is hanging out of the shell or is no longer in the shell and is not moving, then it is dead.  You will need to remove it as soon as you can to prevent the spread of any diseases.

nice snail

What to Do With a Dead Snail

After you have removed the dead snail from the aquarium you need to change the water immediately.  Their guts will decompose rapidly within a few hours after they die.  The shell will not decompose until it is crushed.  You need to remove it carefully, especially if you have more snails in the aquarium. 

Before you get rid of the dead snail, take all the other snails out and put them in clean water until the aquarium is cleaned.  Cleaning the aquarium will help reduce the risk of spreading anything to the other snails.


  • The smell test is the most accurate way to tell if it is dead or alive.  It will start to reek soon after dying.
  • If you snail has not moved in two days, you should consider smelling it to see if it reeks. 
  • Your snail is probably alive if their foot is attached to any component in the aquarium or the filter, then it is still alive.
  • Make sure that you do not overcrowd your aquarium with too many snails and that they are all the same nature and species.
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Hi! I'm Anna and I´m a certified cynologist (KAU, ACW). Expert, blue cross volunteer, owner of Chinese crested kennel "Salvador Dali" and breedless friend called Fenya. "I can't imagine my life without dogs and I totally support the idea #AdoptDontShop".