What To Do If My Mystery Snail Lays Eggs?

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Finding a clutch of mystery snail eggs can be overwhelming, especially to aquarists who have never encountered them before. That was at least how I felt a few years back. Fortunately, as time passed, I gained a lot of experience in this field.

There are three main options you can choose from with mystery snail eggs:

  • Raise the eggs by keeping them in a moist and warm environment.
  • Eliminate the eggs manually.
  • Drown the eggs and use them as a food source for your fish.

As we move forward, I will elaborate on each option. I will discuss what steps you should take if you wish to raise the eggs or what you should do if you wish to avoid a large population of baby mystery snails.

Mystery snail eggs in different development stages.

Still curious? Feel free to check my complete guide on mystery snail eggs. There, I discussed how to care for the eggs, what their stages are, how to tell if they are fertilized, and much more

What To Do If My Mystery Snail Lays Eggs?

Mystery snails will lay their eggs above the waterline. They have a pink color that makes them easy to spot. When you first notice them, you will take one of three options at your disposal:

1. Raising the Eggs

You cannot make this decision lightly. Mystery snails can lay new eggs every week, with each cluster boasting 50 to 300 eggs.[1] Admittedly, this doesn’t happen continuously. 

The creatures take breaks of two to three months between egg-laying sessions. In other words, mystery snails will add offspring to your tank three or four times a year.[2] 

Are you willing to raise all those eggs? You should answer this question before you proceed. Don’t forget: mystery snails can store sperm. Therefore, even if you keep the genders separate, a mystery snail can still overwhelm your tank with eggs.

For the most part, mystery snail eggs are self-sufficient. If you live them alone, they will hatch in a week or two. The sac keeps the embryos safe, providing all the nutrients they need to thrive. 

The eggs must remain warm and moist, which is why many aquarists prefer to leave them above the waterline. They are less likely to dry out. However, drowning is a significant concern. 

Snails have gills and lungs, but they extract oxygen from the atmosphere. If a cluster unsticks from the glass walls and falls into the water, the embryos will drown before they can hatch.

But you can avoid this outcome by taking action. Move the eggs to a plastic container. Placing them on a damp cloth will give the eggs the moisture they need. Don’t forget to cover the container with a lid.

Again, the mystery snail offspring require warmth. Although, you should remove the lid every day to introduce fresh air to the container. This allows you to observe the progress the eggs have made.

You can send them to their new aquarium once they hatch. The eggs will only hatch if you maintain the appropriate conditions, which include a temperature of 76 to 82 degrees F and high humidity. 

Newcomers may struggle with the prospect of moving mystery snail eggs from the aquarium to a separate container. These eggs are soft and fragile. As such, you run the risk of destroying them.

This risk reduces over time because the eggs will eventually harden, taking on a dark color, especially if you have a fertilized cluster. 

Don’t expect the eggs to give you the option of waiting until they harden. If the cluster starts unsticking from the wall, you should move it to the container, regardless of the risk.

Mystery snail eggs that are attached to the aquarium’s wall.

2. Eliminating The Eggs

Mystery snails are not pests, not in the traditional sense. They have numerous benefits. For instance, they are tank cleaners that eat algae. In fact, a sizable mystery snail population can keep the algae infestation in your aquarium under control.[3]

These creatures can become a menace if you allow them to multiply. If you don’t have enough room, they can crowd the tank, crashing the nitrogen cycle and introducing an oxygen deficiency. 

Even if you have a large tank with an efficient filter, snails are not visually appealing, not when you have so many of them that the creatures have covered every visible surface. 

If you don’t have the time or resources to raise the mystery snails, eliminate them. But how does that happen? How do you dispose of unwanted mystery snails?

The first step is the most obvious. Mystery snails lay eggs above the water line. Find the clusters and scrape them off the wall. But what happens next?

A paper in the Philippine Rice Research Institute, published in 2017, complained that snails went largely unnoticed in discussions about invasive non-native species because news publications preferred to highlight the destructive consequences of introducing predators like pythons and stinging insects to foreign environments.[4]

People ignore snails because they are not inherently dangerous to humans. They won’t bite you. More importantly, the creatures are inconspicuous. People cannot help but ignore them. 

This is why a CBC news report went to great lengths to highlight the impact snails could have on a water body’s chemistry; snails that people had introduced to the wild by carelessly discarding their aquariums.[5]

A study from SUNY College of Environmental Science and Forestry found that aquarists could ease the suffering of invertebrates by exposing them to beer before ultimately euthanizing them.[6]

But eggs are somewhat different because they haven’t hatched. Flushing them down the toilet is not a good idea because the eggs may survive. And again, you shouldn’t introduce invasive species to native environments. 

Many aquarists will simply wrap the eggs in a towel before crushing them with a heavy object. You can also expose them to destructive components like salt water and bleach. If the eggs are dead, you can throw them in the trash

3. Feeding The Fish

Aquarists with aggressive fish like bettas will have an easier time eliminating mystery snail eggs. Scrape the eggs off the wall and allow them to sink in the water. The fish will do the rest. 

They don’t discriminate. Fish will eat whatever fits in their mouths. They will make short work of a cluster of snail eggs. 

Some people use snail eggs to supplement a fish’s diet. They will breed snails for the express purpose of using their offspring as food. Some people wait for the eggs to hatch before adding them to the aquarium during mealtimes. 

Either way, species like gourami, yoyo loaches, and Bala sharks will appreciate the protein-rich meals.

Naturally, you should watch the aquarium carefully. Yes, snail eggs and baby snails are rich sources of protein. But your fish may ignore them. And if snail eggs remain uneaten for an extended period, they will rot.

The ammonia and nitrate levels will increase, poisoning the fish. You can mitigate this risk by removing the eggs if your fish have clearly rejected them. You can’t rely on the filter to siphon the eggs out of the water.

Fish the eggs out of the tank manually and throw them away. You should do the same for dead baby and adult mystery snails the fish have refused to eat.

One-week-old mystery snail eggs.

How Long Do I Have Until The Eggs Hatch?

As you can see, there are different courses you can take when it comes to mystery snail eggs. But regardless of what you choose, you must consider that fertilized eggs will hatch within three weeks.

Some aquarists remove the eggs because they believe they haven’t been fertilized, while in truth, the owners didn’t wait long enough.

You can tell that baby snails grow inside the eggs by observing their appearance. Fertilized eggs will darken over time. They will look like they are covered with mold.

How Do I Know If The Eggs Contaminated My Tank?

Feeding the mystery snail eggs to your fish is a reasonable solution. Unfortunately, some eggs may sink to the corners or get underneath the substrate. That will make it difficult for the fish to find them.

Over time, these eggs will rot and contaminate your tank. The best way to catch the situation in time is to measure the water with a dedicated kit. I personally use the well-known API FRESHWATER MASTER TEST KIT (link to Amazon).

The ammonia, nitrite, and nitrate should be at 0 ppm. If they are higher than that, remove the eggs manually and perform a 10-20 percent water change.

An excellent video showing how to care for and hatch mystery snail eggs.

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If you like the idea of having baby snails in your tank, you don’t have to do much. If the environment was comfortable enough for the snail to lay the eggs, it is good enough for the eggs to hatch.

Just make sure the eggs don’t fall into the water, as that will suffocate the babies. However, mystery snails can lay hundreds of eggs, which can quickly overpopulate your tank.

If you wish to avoid that, all you have to do is to drown the eggs. The fish in your tank will gladly eat them. Just make sure to remove the eggs your fish ignored. Otherwise, they will rot and produce ammonia. 

Using a test kit, you’ll know if toxins like ammonia and nitrite rose above 0 ppm. If they did, remove the eggs manually and perform a large water change.


  1. https://mystery-snails.com/mystery-snail-eggs/
  2. https://www.intoyard.com/how-many-eggs-mystery-snails-lay/
  3. https://aquaticarts.com/pages/mystery-snail-care-guide
  4. https://www.hawaii.edu/cowielab/Joshi%20et%20al%202017%20Invasive%20Apple%20Snails%20Book.pdf
  5. https://www.cbc.ca/news/canada/new-brunswick/chinese-mystery-snail-study-1.5140445
  6. https://www.sciencedaily.com/releases/2016/10/161006092859.htm