How To Tell If Leopard Gecko Eggs Are Fertile Or Infertile

Your leopard gecko is pregnant, and the big day has finally arrived.

You have watched your leo furiously digging in her nesting box, and you know egg-laying is imminent.

When she is done, you see two eggs in the nesting box and move them to an incubator.

The only thing left to do is check the eggs for fertility signs, but how do you do this?

Leopard gecko eggs are determined to be fertile or infertile through a process known as candling. Candling is done by shining a very bright light on the eggs to see what is inside them. When you see veins and a shadow in the egg, it’s a fertile leopard gecko egg.

Some leopard gecko keepers remove the egg from the incubator to candle it, but this often disrupts the temperature and humidity inside of the incubator. 

In most cases, it is entirely possible to candle the egg without removing it from the incubator.

It is important to allow the egg to incubate until you are entirely sure it is not fertile before discarding it.

Keep reading for more information on how to determine if a leopard gecko egg is fertile or infertile, as well as proper incubation techniques. 

leopard gecko eggs fertile or infertile

Fertile Eggs vs. Infertile Leopard Gecko Eggs

Leopard gecko egg candling is the easiest way to determine whether they are fertile or infertile.

You will need bright light, such as a small flashlight, and a darkened room to candle an egg. 

Gently place the light on the top of the egg, and it will glow, allowing you to see what is inside.

In a fertile egg, the outer surface will be a chalky white, and the texture will feel leathery. 

When you are candling the egg, you will see a pink color along with some faint lines, which are veins. 

As incubation progresses, you may even see a small circular red shape.

Infertile eggs will have a more irregular outer appearance. 

There will be translucent patches on the shell, and it may appear to be shiny. 

Candling the egg will reveal a yellow color inside, with no presence of any veins.

Even if the egg appears to be yellow inside, you should still allow it to incubate if there is a small chance the egg is fertile. 

Many leopard gecko owners have reported an egg hatching even though it appeared to be yellow inside.

If the egg is truly infertile, it will grow mold, become discolored, and eventually rot. 

Once the egg develops a foul odor, you should remove the egg from the incubator to keep the mold from spreading to the healthy egg. 

If a healthy egg develops mold, you should gently treat it with some anti-fungal medicine.

Occasionally, an egg may have a small dent in it. 

This does not necessarily mean the egg is infertile. 

A dent in an egg is usually a sign the egg is too dry, and the dent will usually disappear when exposed to high humidity.

If you’re having problems with this we have a post covering dented eggs with leopard geckos you should check out.

Will My Female Leopard Gecko Lay Eggs Without Mating?

Female leopard geckos are capable of storing sperm for several months.

Your leo may have mated before you got her, and you may not even know until she lays her eggs.

Female leopard geckos will lay several clutches of eggs during the six months after she has mated.

Even if a female leopard gecko has never mated in her life, it is still possible for her to lay eggs.

Once a female leopard gecko has reached sexual maturity, usually between 18-24 months of age, she will begin ovulation. 

When the female begins ovulating, she will start laying eggs at regular intervals or absorb the eggs into her body.

The eggs a leopard gecko lays without mating will always be infertile (click link for more information on this topic).

You should monitor your female leo’s appearance regularly, and if she starts gaining weight, you will need to investigate whether or not she is gravid. 

If you are an inexperienced leopard gecko owner, you may want to seek the advice of a veterinarian.

Even if the eggs are infertile, it is still important to increase the amount of calcium and other vitamins in your leo’s diet to prevent complications such as egg binding.

How To Properly Incubate A Leopard Gecko Egg

Before your leo lays her eggs, you will need to set up an incubator box, so it is ready when the time comes.

It’s possible to use a commercial incubator, but a DIY incubator is more cost-effective unless you plan to become a breeder.

To make an incubator, you will need a small plastic container with a lid.

Fill the container with around 4″ inches of moist perlite and vermiculite mix to maintain the humidity.

Poke several holes in the lid to allow for proper air exchange.

Within a day or two of your leopard gecko laying her eggs, you will need to carefully transfer them from the egg-laying box to the gecko egg incubator. 

Avoid rolling the eggs during this process, as turning them will kill the embryos. 

Some leopard gecko owners will gently mark the top of the eggs with a marker.

You do not want to bury the eggs completely, but you will need to cover them with a small incubation medium.

Use a heat lamp or an under-tank heater to keep the eggs warm, and mist the sides of the container occasionally when it becomes too dry. 

Avoid directly spraying the eggs because this will quickly lead to mold growth.

The optimal temperatures in the incubator are between 75-93° degrees Fahrenheit (33° C), and the humidity should be between 85%-95%.

The incubation temperature of the eggs will determine their sex, which is known as temperature-dependent sex determination. 

A higher temperature of 93° degrees Fahrenheit (33° C) will produce males, while a lower temperature of 79° degrees Fahrenheit (26° C) will produce females.

Using a thermostat with your heat source will allow you to control the temperature in the incubator. 

You should also regularly monitor the temperature with a thermometer to ensure your thermostat is accurate. 

Use a hygrometer to measure the humidity level.

The eggs will need to have anywhere from 35 to 100 days of incubation before they hatch. 

Hatching time varies according to temperature. 

With higher temperatures, the incubation period will be much shorter.

When it is time for the eggs to hatch, they will deflate and become dented. 

The shell will become thinner, allowing the hatchlings to create an opening in the shell. 

It may take several hours for the hatchling to appear.

Do not disturb the eggs during incubation or the hatching process, as this could cause damage to the hatchlings.

For a full guide, check out our dedicated article on how to incubate leopard gecko eggs.

How To Care For Hatchling Leopard Geckos

When the hatchlings emerge, you will need to move them to separate small enclosures along with what remains of the egg. 

Keeping the egg remains with the hatchlings is vital because they will get nourishment from the yolk sacs left for several days.

The substrate in the hatchling enclosures should consist of paper towels for easy cleanup and ensure the hatchlings’ safety. 

A loose substrate should not be used, as the small particles are easily ingested by the baby leos, leading to impaction.

After this period, the hatchlings will become more active, and they will be ready to eat solid food, such as crickets. 

The crickets should be properly gut-loaded to provide more nutrition, and they should not be larger than the width between the leopard gecko’s eyes.

You will also need to provide the baby leopard geckos with a shallow dish of clean water, so they are properly hydrated.

It is not advisable to house hatchlings together because they may become aggressive toward each other and cause injuries. 

You should also never place hatchlings in the same enclosure as older hatchlings or adults because they will likely be bitten or killed.

Learn more about taking care of leopard gecko babies.

Since the baby leos will be shy or scared of you at first, you should provide them with hides, so they have a place to escape and feel safe.

You should not handle the hatchlings, but it is important to look in on them to become used to you. 

The baby leos will probably spend their first few weeks hiding from you, but as they become more comfortable with your presence, they will stop hiding so much.

What To Do If Your Leopard Gecko Becomes Egg Bound

Egg binding, also known as dystocia, is when a female leopard gecko cannot lay her eggs. 

The gecko will strain herself laying the eggs, and she will begin to appear lethargic and inactive.

The excessive straining may even cause the female to suffer a prolapse.

Check out our post on prolapse in leopard geckos for some quick solutions if this happens.

Egg binding is caused by poor nutrition, mainly due to a lack of calcium in the leopard gecko’s diet. 

Gravid females need extra calcium to form healthy eggs and produce the contractions necessary to lay them.

Egg binding is a very serious issue, and you need to seek veterinary care immediately. 

Never remove the eggs yourself, as you may cause serious injury to your gecko.

If egg binding is not treated as soon as possible, serious complications will occur, and your leopard gecko may even die.

Egg binding is more common in older female leopard geckos, but it will happen at any age if there is a nutritional deficiency.

Increasing calcium and vitamin D3 supplements is essential as soon as you realize your female is pregnant to prevent egg binding. 

Egg production and laying cause a lot of stress on a female gecko’s body.

Commonly Asked Questions

How will I know if my leopard gecko is pregnant?

The average leopard gecko pregnancy lasts anywhere from 2-5 weeks. 

If you have knowingly bred your female, you will start to see pregnancy symptoms within days after mating.

A gravid leopard gecko will become less active and will start to gain weight. 

During later stages of pregnancy, you will be able to see the bulges of the eggs in the female gecko’s lower abdomen. 

Do not apply any pressure to the gecko’s belly because you will risk rupturing the eggs.

The female will start to dig a lot right before she lays her eggs to prepare a nest.

How many eggs are in a leopard gecko’s clutch?

A female leopard gecko will typically have 1-2 eggs per clutch. 

It is more common for the leo to only have one egg in her first clutch and two eggs in the subsequent clutch.

How many clutches will a leopard gecko have in a year?

A female leopard gecko between 2-5 years of age will lay between 4-10 clutches per year. 

Older females may only produce 2-3 clutches in one year.

How long will it take for a pregnant leopard gecko to lay her eggs?

Once a female leopard gecko becomes pregnant, it will usually take two to five weeks before she lays her eggs.

At what age can I safely begin breeding my leopard gecko?

Female leopard geckos usually reach full sexual maturity between the ages of 18-24 months old. 

However, this does not mean you should start breeding your female right away.

How much your leo weighs plays an integral part in when she will be able to breed safely. 

The female should weigh between 35-40 grams before breeding her.

Is my older leopard gecko still able to breed?

Depending on its health, a male leopard gecko will breed until it is around eight years old.

However, since producing and laying eggs causes so much stress to a female leopard gecko’s body, she should not breed past six years of age. 

She will still be able to produce eggs at 7-8 years old, but she will not lay many clutches, and there are many more risks involved.

Aside from possibly becoming egg-bound, the stress of the pregnancy on the female’s body may be enough to kill her.

When is the breeding season for leopard geckos?

While leopard geckos can breed throughout the year, they usually do not breed during the coldest winter months.

The typical breeding season for leopard geckos lasts from February through October.

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