Mystery Snail Eggs Growth Stages: A Full Guide With Pictures

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I remember how impatient I was when I encountered my first mystery eggs clutch. As I wanted to raise the eggs, it was crucial for me to know what their growth stages were. Fortunately, after raising hundreds of snails, I gained a lot of experience in this field.

These are the growth stages of mystery snail eggs:

  • Stage 1 (days 1-2): Pinkish, round, soft, and small.
  • Stage 2 (days 3-7): Garnet brown, hardening shell.
  • Stage 3 (days 7-10): Gray shades, irregular shapes.
  • Stage 4 (days 11-21): Moldy appearance, varying sizes.

As we move forward, I will share some detailed pictures to help you understand the different stages. Then, I’ll discuss what happens to unfertilized eggs and what would be the right stage to move the fertilized ones into an incubator.

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 Are The Mystery Snail Eggs Growth Stages?

Most freshwater snails lay eggs in clumps that attach to walls, plants, and other hard surfaces above the waterline. They have multiple spawning sessions throughout the year, laying dozens, possibly even hundreds of eggs.

Mystery snails have all these attributes and more. The eggs they lay are soft and pink at the start. This is true for both fertile and infertile eggs:

Some people identify infertile eggs by their smell, and for a good reason. Infertile eggs will develop a terrible smell by the second week, compelling consumers to either crush, freeze or feed the eggs to the other inhabitants of the tank.

All three options seem excessive. However, many aquarists are hesitant to throw these clusters in the dumpster because some of the eggs may hatch, and the last thing you want is to find a growing population of snails in your bin.

You are better off crushing the eggs or keeping them in an airtight Ziplock bag before throwing them away. 

But if your eggs are fertile, you don’t have to sniff them. Infertile eggs will remain unchanged. On the other hand, fertile mystery snail eggs will only remain soft and pink for the first 48 hours.

Admittedly, you cannot expect every cluster of eggs to follow the same growth trajectory. 

Many aquarists have posted pictures of egg clusters that remained soft and pink for longer than expected, at least on the outside.[1] But you don’t have to obsess over an egg cluster’s growth rate. 

Remember that fertile eggs will change over the next few days and weeks, growing darker and hardening before finally adopting a garnet brown color:[2]

This assumes that you maintained the appropriate parameters, including moist conditions and temperatures of 76 to 82 degrees F. 

A research article by Moniruzzaman Sarker, Sarwar Jahan, and Badrun Nesa found that a freshwater snail’s health was susceptible to environmental factors like pH, dissolved oxygen, and water hardness.[3]

According to the research paper, snails are particularly sensitive during embryological development, alerting aquarists to the fact that fertile eggs can dry out and die unless you rear them in a conducive environment. 

This explains the penchant some individuals have for keeping eggs in incubators. An incubator gives the aquarists more control over the egg’s environment.

If you are not sure whether your mystery snail eggs are fertilized, feel free to check this article, where I discussed all the characteristics of fertilized and unfertilized eggs.

How Do You Know When Mystery Snail Eggs Are Ready To Hatch?

Eggs are pink at the start, but they grow darker and harder over the days and weeks. They will take on a moldy appearance as they near the end of their gestation period:

The cluster will also take on a slimy texture. The center will become darker as the baby snails chew their way to freedom.

Ana R.A. Coelho, Goncalo Calado (Universidade Lusofona de Humanidades e Tecnologias), and Maria Teresa Dinis (Universidade do Algarve) published a paper that noted that hatching from a single egg cluster (Pomacea bridgesii) could take as many as 20 hours.[4]

Some people don’t need to understand an egg cluster’s growth stages because they don’t want to interfere with the snail’s breeding habits. This mindset is not wrong.

Ultimately, mystery snail eggs can thrive if you live them alone. An egg cluster will remain in place unless the surface is too damp. 

You can monitor the cluster, watching as the colors change and waiting to take action if the clutch loosens its grip on the hard surface. 

If the cluster’s development proceeds without incident, you will notice fuzzy mold as the eggs harden and darken.

During Which Stage Can I Move The Eggs?

Once the babies emerge, you can take the appropriate steps to care for them. Although they can survive on what is left of the cluster for the first few days. It has plenty of calcium. 

But even after they absorb the clutch, you don’t have to engineer a special diet for the creatures. They will eat whatever the adult snails enjoy.[5]

But what if you prefer to play an active role in the hatching process? In that regard, you need to understand a snail egg’s development. You cannot afford to move the eggs immediately after they hatch.

The cluster is too soft and delicate. You may destroy the eggs along the way. You can confirm your suspicions by prodding the eggs with your fingers. The delicate texture will probably dissuade you from handling the eggs.

But if you understand the growth stages, you will remember that the eggs harden after a few days. In other words, wait three or four days before handling them, preferably on stage 2.

Use a thin, flat item like a credit card that can slide beneath the cluster without harming the eggs. The object will detach the eggs from their home as it slides below them.

Don’t be surprised if some of the eggs at the bottom incur damage. It is a necessary risk.

Some people cannot afford to wait. They want to move the eggs to protect them from the poor conditions in the aquarium or the predators that want to eat them

In those situations, you can try moving the cluster before it hardens. But again, this is a risk. You could lose the entire cluster. Although, the snail would simply lay more eggs in a few weeks. 

Aquarists with nerite snails in freshwater tanks are accustomed to these transitions because nerite eggs require brackish water to hatch. These individuals transfer snail clusters from container to container all the time.

What If I Damage The Eggs?

If you’re new to mystery snails, the creatures produce dozens of eggs several times a year. Therefore, you have plenty of room to practice. If you don’t want the mystery snail population in your aquarium to increase, eliminate the eggs before they hatch.

You can always euthanize the baby snails after they hatch. But many newcomers are squeamish. The notion of killing living, breathing creatures makes them uneasy. They prefer to discard the eggs before the snail offspring emerge. 

While most eggs hatch within two to three weeks, some eggs can take as many as five weeks to hatch. However, others will add new snails to your tank in as little as seven days. 

Therefore, you should assume that you have six days to determine whether or not you want the eggs to hatch.

What Are The Stages Of Unfertilized Eggs?

As I mentioned earlier, mystery snails can lay unfertilized eggs. But obviously, they won’t go through the stages of fertilized ones.

In the beginning, fertilized and unfertilized eggs look the same. They are both round, tiny, and pinkish.

You will start noticing the differences towards stage two. While fertilized eggs will turn garnet brown, unfertilized eggs will remain pink. They will also stay soft while fertilized eggs harden.

After ten to fourteen days, unfertilized eggs will develop a distinct, uncomfortable smell you cannot miss. That typically means the eggs have rotten, and you should remove them immediately.

Unfertilized eggs will also turn white at some point. That can be a bit confusing as fertilized eggs also become white when the snails are about to hatch.

However, unfertilized eggs will skip the moldy stage. They will go from pink to white without changing to other colors in the middle. That usually indicates a fungal infection or that the eggs have dried out.

Bear in mind that you can have both fertilized and unfertilized eggs in the same clutch. That is pretty common as mystery snails can lay up to 500 eggs, of which only 20 to 40 will eventually hatch.

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The growth stages of mystery snail eggs are pretty repetitive. In the beginning, they will be pinkish and small. That is true for both fertilized and unfertilized eggs.

After three days, fertilized eggs will develop garnet brown shades, and their shell will harden. That is as opposed to unfertilized ones that remain pink.

After a week, the eggs will go from brown to gray, and after a few more days, it will look like the clutch has developed mold. That is merely the baby snails seen from the outside.

Unfertilized eggs typically turn from pink to white as they eventually dry out or rot. They won’t develop brownish or grayish shades at any point.