How Long Do Mystery Snail Eggs Take To Hatch?

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Finding a clutch of mystery snail eggs can be pretty exciting. But they also raise many questions. For example, one of the first things I wondered was how long it would take for them to hatch. Fortunately, over the years, I gained a lot of experience on this topic.

It takes about three weeks for mystery snail eggs to hatch. To achieve that, they must remain just above the water line at a temperature ranging between 68 to 84 degrees F. Over time, the eggs will darken, which is a sign that they are fertilized.

As we move forward, I will discuss what may prevent your mystery snail from hatching after three weeks. I will also mention the signs indicating that the eggs are not at all fertilized.

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

How Long Do Mystery Snail Eggs Take To Hatch?

Mystery snail eggs typically hatch within three weeks.[1] When they first emerge from the female snail, they have a soft and milky appearance, which is why you cannot move them.

Doing so will destroy the eggs. But if you wait a few hours, the shells will harden, taking on a darker color.[2]

You can leave them alone. Snail eggs are self-sustaining. They don’t need anything from you. Aquarists will only intervene when a clutch of eggs begins to drift away from where it was laid.

Otherwise, the eggs will survive alone, especially if the parent lays them above the waterline. Snails can lay multiple clutches of eggs over several days.

Therefore, the hatching time will vary depending on when the eggs were laid. Naturally, the clutch the snail laid first will also hatch first. For instance, one clutch may hatch at ten days while you have to wait 14 days for the other to do the same.[3]

A mystery snail’s gestation period is not particularly important because many aquarists hate freshwater snails. They treat the creatures like pests.

But even among aquarists that rear mystery snails, the gestation period is not vital because the eggs don’t need your help.

The gestation period won’t factor into your plans and maintenance routines. It only matters if you haven’t created a conducive environment for the baby snails, and you need to know how much time you have before your mystery snail’s offspring arrive.

Why Are My Mystery Snail Eggs Not Hatching?

Snails require specific conditions to thrive. A Parasite and Vectors paper analyzing snail populations in the Ethiopian Rift Valley created a connection between variables like oxygen levels, alkalinity, and Physico-chemical parameters and the abundance of snail species in the region.[4]

Snail eggs are similar. Their health is tied to numerous variables. The presence or absence of those factors will influence their ability to hatch.

If your mystery snail eggs don’t hatch, you should look at one or more of the following:

1. The Eggs Were Not Fertilized

Are your mystery snail eggs fertile? This question matters because infertile eggs cannot hatch, and unfortunately, mystery snails lay infertile eggs all the time.

You can identify them by their foul smell.[5] Some newcomers ignore the scent because they expect aquariums to generate revolting odors. But that couldn’t be further from the truth.

First of all, aquarium water shouldn’t smell. If your water has a disturbing scent, something has gone wrong. More than likely, you haven’t performed the necessary water changes.

Secondly, fertile eggs do not smell, at least not in the same manner as their infertile counterparts. If you still have doubts, place the eggs on a damp cloth. If they create pinkish stains, the eggs are infertile.

You should wait a few days before attempting to distinguish between fertilized and unfertilized eggs. Otherwise, you may remove fertilized eggs while trying to eliminate the unfertilized offspring.

Wait two weeks and inspect the eggs. The infertile eggs will maintain the same pink color they had at the start.[6]

On the other hand, the fertile eggs will change gradually. The sizes of the individual eggs in each clutch will vary because they won’t grow at the same rate.

2. The Temperature Is Wrong

You should maintain a warm aquarium to accommodate the mystery snail eggs. Aim for temperatures of 68 to 84 degrees F. Lower temperatures will extend the gestation period.

If they are low enough, the temperatures may prevent the eggs from hatching in the first place. Do you have a heater in the tank? What about a thermostat?

Newcomers have a bad habit of setting the temperature and forgetting about the variable. But that is a mistake. Like all other vital parameters, you should test the temperature routinely, especially when you perform a water change.

Amateurs do not realize that a water change can either raise or lower the temperature, drastically altering the conditions in the aquarium.

To create a stable environment, I personally suggest getting the well-known Orlushy Submersible Aquarium Heater (link to Amazon). Just make sure you pick the one that suits your tank’s size.

3. There Is Not Enough Humidity

Have you noticed how snails lay eggs just above the water line? They can lay their eggs away from the water to protect them from predators like angelfish.

But they don’t do so because the eggs must remain moist. Low humidity is dangerous because it allows the eggs to dry, essentially killing them.

You can take this into account when conducting water changes. When you fill your tank with new water, try to maintain the same gap there was before.

4. The pH Is Inappropriate

The pH is just as important to eggs as it is to their parents. Keep this variable within the 7.6 – 8.4 range. A low pH won’t do the snails any good. The creatures will develop fragile shells that leave them vulnerable to various health issues.

Since the eggs are outside the water, maintaining the right pH is essential to the snails themselves. However, healthy parents will produce eggs with stronger shells.

5. The Eggs Are Under Water

Have you given the water level any thought? Newcomers don’t understand why snails lay eggs above the waterline. After all, if the goal is to keep the eggs moist, why not lay them below the waterline?

Yes, mystery snails have gills as well as lungs. But unfortunately, they get their oxygen from the atmosphere. In other words, if a clutch of mystery snail eggs falls below the water line, the embryos will drown. They won’t hatch.

If your mystery snail’s eggs fell into the water, you should bring them back up. Place them just above the water line. It might be too late, but it’s worth a try.

6. There Is Too Much Ammonia

This goes without saying. You cannot keep mystery snail eggs in an ammonia-rich tank. Ammonia is toxic. The substance kills organic creatures, and snail eggs are no different.

Even though the eggs are above the water line, ammonia evaporates pretty quickly. It will hurt the eggs in its gaseous form nevertheless.

To keep track of ammonia, nitrate, and nitrite, I personally got the API FRESHWATER MASTER TEST KIT (link to Amazon). This one is highly accurate and lasts for about eight hundred measures.

These three toxins should be kept at about 0 ppm. To ensure this, make sure you perform routine water changes (of about 15 to 20 percent each week).

How Long Can Mystery Snails Hold Eggs?

Mystery snails are unlikely to hold eggs. A 2017 study looking at the impact of predators on the behavior of freshwater snails found that the creatures were more likely to produce eggs earlier if the predation risk was high.[7]

Fish are different. Some of them can withhold their offspring in the presence of predators.

You cannot always predict a snail’s breeding behavior. Mystery snails can hold sperm for nine or more months.[8] Therefore, a female snail you just brought home may surprise you with new babies in the absence of a male snail.

Many beginners do not realize that a mystery snail can mate in a fish store before laying eggs months later once it reaches the home aquarium.

It won’t even occur to them to associate the unexpected clutch of eggs with the new mystery snail. But while the mystery snail will hold sperm, it is unlikely to do so for the eggs.

Although, some aquarists have observed mild delays in egg—laying originating from the poor conditions in the aquarium.

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You can expect your mystery snail eggs to hatch after three weeks. But that isn’t written in stone, as some eggs will take longer or shorter than that. Three weeks is the average.

If the eggs aren’t hatching, they may not be fertilized, as mystery snails lay unfertilized eggs all the time. One sign will be a foul smell coming from your tank.

Another sign is the eggs’ appearance. Fertilized eggs gradually turn darker and develop moldy shades. Nevertheless, unfertilized ones will remain exactly the same.

Meanwhile, it would be best to adjust the water parameters, especially the temperature, as it directly impacts the eggs’ development. It is also crucial to get rid of ammonia, as it can quickly evaporate and ruin the eggs.