How To Tell If Your Leopard Gecko Eggs Are Fertile

If you’re a leopard gecko breeder, knowing whether your eggs are fertile or infertile can save you time and effort. This comprehensive guide will walk you through everything you need to know about identifying fertile leopard gecko eggs.

If you’re short on time, here’s a quick answer: Look for veins inside the eggs, listen for tiny heartbeats with a stethoscope, and watch for slight movements inside the egg to determine if leopard gecko eggs are fertile.

Examining Egg Veins

Prominent veins indicate embryo development

One of the best ways to determine if leopard gecko eggs are fertile is to examine the egg veins. As the embryo inside the egg develops, it will need a steady supply of oxygen and nutrients. This is delivered through a network of veins that become more prominent over time.

Fertile eggs will initially have a faint spiderweb-like network of veins on the surface. But as the gecko embryo continues growing inside the egg, these veins will become thicker and much more noticeable. By candling the egg and shining a light through it, you can view the vein network pattern.

Eggs that are infertile or contain embryos that died off early will lack a defined vein network. The veins will appear very faint if they are present at all. So prominent thick veins are a sure sign of a healthy developing embryo!

Veins get more defined over time

It’s important to examine the egg veins at multiple points during incubation. Right after the eggs are laid, the vein network will be very minimal. But around 30 days into incubation, fertile eggs will showcase an intricate web of surface veins.

Not only do the veins become more defined, but they may also change color. Healthy veins will usually take on a dark red or purple color. Some breeders even track the vein color changes day-by-day to monitor embryo progress.

Here is a simple vein development guide according to incubation days:

So if you candle your leopard gecko eggs and see those veins getting big and bold as incubation continues, there is an excellent chance the eggs are fertile! Just be patient and let those veins develop. By 35 days, obvious well-defined veins indicate the embryo is progressing perfectly.

Listening for Heartbeats

Use a stethoscope placed on the egg

One of the best ways to tell if leopard gecko eggs are fertile is to listen for heartbeats. This can be done by carefully placing a stethoscope on the surface of the egg and listening closely. The embryonic heartbeat is usually detectable within the first 2-3 weeks of incubation if the egg is fertile.

The heartbeat will sound rapid and rhythmic, similar to a human fetal heartbeat. As the embryo develops, the heartbeat will become louder and more pronounced. Listening for heartbeats with a stethoscope is a non-invasive method that allows breeders to determine fertility early on without disturbing the eggs.

To listen for heartbeats, first sanitize the end of the stethoscope that will touch the egg surface. Gently place it against the egg and listen intently for any faint rhythmic sounds. It may take a few minutes for the heartbeat to become audible.

Move the stethoscope around to different areas of the egg surface. Press lightly to make good contact with the shell, but not hard enough to risk damaging the egg. Listen for up to 5 minutes before determining if a heartbeat is present or not.

The optimal incubation temperature for leopard gecko eggs is 88-92°F, so make sure the egg is being properly incubated before assessing for heartbeats.

Once embryonic heartbeats are audible, the eggs can be candled for further verification. Candling involves shining a bright light through the egg to observe the developing blood vessels or embryo inside. But listening with a stethoscope first provides a great initial assessment of fertility.

Heartbeat confirms live embryo

The presence of an embryonic heartbeat is a definitive sign that a leopard gecko egg contains a living embryo and is fertile. It indicates the egg has been successfully fertilized and the embryo is progressing through early development.

The embryonic heart starts beating around day 10-14 of incubation, so a heartbeat detectable via stethoscope confirms the embryo has reached this important milestone.

A healthy leopard gecko heartbeat generally ranges from 90 to 220 beats per minute during early incubation. The rate may be on the slower end initially and then speed up as the embryo grows. A strong heartbeat means blood is pumping and the circulatory system is developing normally.

It is an excellent indication the embryo is thriving.

While an audible heartbeat strongly suggests the egg is fertile, the absence of a detectable heartbeat is not absolute proof that an egg is infertile. It is possible for the embryo to die after the heart initially forms. An egg that was fertile may show no heartbeat if the embryo perished.

Candling the eggs provides more definitive evidence of an active embryo or lack thereof. But listening for heartbeats allows breeders to assess fertility non-invasively and take appropriate next steps.

Observing for Movement

Look closely for subtle twitches

One of the earliest signs that leopard gecko eggs are fertile is subtle twitching movements inside the egg. These small twitches indicate that the embryo inside is alive and developing as it should. To spot this movement, you’ll need to observe the eggs very closely, preferably with a bright light source behind them.

The twitches can be extremely subtle at first, just tiny vibrations against the inside of the egg shell. As the embryo grows over the incubation period, the movements will gradually become larger and more pronounced.

Try candling the eggs every few days by holding a flashlight up behind them in a dark room. Look for any shadows or silhouettes shifting slightly inside. You may even see a tiny gecko arm or tail bump against the shell!

Seeing consistent movement is a very positive sign that the eggs are fertile and progressing normally. If you don’t notice any motion after the first 2 weeks of incubation, the eggs are likely infertile.

Movement means the embryo is alive

Visible motion or twitching inside a leopard gecko egg indicates the embryo has developed past the initial cell division stage and progressed to organ formation. At this stage, around 2-3 weeks into incubation, the tiny gecko begins spontaneously moving and shifting inside the egg as its muscles and nervous system start functioning.

These natural movements are your confirmation that the embryo is alive and the egg is fertile.

While microscopic cell growth cannot be observed without candling, once an embryo has formed, its movements create visible vibrations against the egg shell. Twitching signifies essential development like a beating heart, flexing spinal cord, and developing limbs.

If you don’t see any signs of motion, it likely means the eggs are infertile or the embryo perished very early on. Consistent movement is an excellent indicator that incubation is succeeding and hatching can be expected!

Candling the Eggs

Candling involves shining a light through the egg

Candling is a simple but effective method for checking the fertility and development of leopard gecko eggs. It involves shining a bright light, such as a flashlight or candle, through the egg shell to visualize what is happening inside without harming the embryo.

When performed properly around 10-20 days into incubation, candling allows leopard gecko breeders to determine if the egg is fertile and developing properly before going full term (45-60 days).

Leopard gecko eggs have calcium carbonate shells which allow light to partially penetrate into the egg when placed up against the light source. Fertile eggs will have darkened veins or embryo shapes visible when candled, whereas infertile eggs will continue to look the same yellow/white color throughout when placed up to the light.

So candling provides a glimpsing insight into fertilization and growth without requiring tricky egg surgery or cracking them open prematurely.

You can see embryo shape and blood vessels

When candling leopard gecko eggs after sufficient incubation, specific developments may be visible that indicate fertility:

• Darkened embryo shape – The outline of a growing baby leopard gecko may be vaguely visible.
• Dark veins or blood vessels – As blood vessels develop they can be seen as darkened branching lines across the egg.
• Darkened air pocket – In a fertile egg the air pocket usually rests diagonally from the embryo and may turn darker colored.

These inner sights when candling signify the egg has indeed been fertilized and embryonic development is progressing. If none of these signs are visible upon candling, the egg is likely infertile and will not hatch.

Candling around 10-15 days after laying is ideal for determining an egg’s early fertility. Then eggs should be candled again closer to their hatching date (45-60 days) to check embryo position and prepare assistance if needed.

Following this candling schedule allows a complete picture of leopard gecko egg fertility during key phases of growth, from first visible developments to final preparations to hatch. Knowing precisely what is happening inside helps provide the conditions needed for the highest hatch rates.

Candling leopard gecko eggs is straightforward – all that’s needed is a bright flashlight and a gently curious breeder! It provides that literally illuminating look inside the calcium walls to reveal if babies are coming or if the clutch was a miss.

So shine some light and take a peek during incubation to enjoy the incredible view of leopard gecko development happening right before your eyes!

Waiting for Hatching

Fertile eggs will hatch in 40-120 days

Congratulations, you’ve got some fertile leopard gecko eggs! Now comes the exciting wait for them to hatch. Fertile leopard gecko eggs typically take 40-120 days to hatch depending on incubation temperatures. Here’s what to expect during this time:

• At around 40 days, you may be able to see the embryos developing inside the eggs if you candle them. Look for signs of movement and growing bodies.
• 60-80 days in, the hatchlings will absorb the remaining egg yolk. The eggs will indent and become very thin.
• Anywhere from 80-120 days, the baby geckos will pierce the egg with their egg tooth and begin hatching! This process can take 24-48 hours from the first pip to fully emerging.

Make sure the eggs are incubated at ideal temperatures between 82-88°F and have appropriate humidity levels around 40%. Avoid candling too frequently or handling the eggs. Let the exciting miracle of life unfold!

Infertile eggs will decay, collapse, or bulge

Not every leopard gecko egg will be fertile, so it’s important to watch for signs of infertility. Infertile leopard gecko eggs may exhibit one or more of these indications:

• Decay and molding – After 2-3 weeks, infertile eggs may begin to cave in, collapse, and grow mold or fungus.
• No veins visible – Fertile eggs will have a network of veins. Infertile eggs remain yellow/white.
• Bulging or exploding – Due to gas buildup, infertile eggs may bulge or even burst.
• No indentation by 80 days – Healthy embryos absorb egg yolk causing indentation.
• No hatching by 120 days – They simply will not hatch if not fertile.

It can be disappointing when eggs don’t turn out to be fertile. Make sure your leopard geckos are healthy and paired at the right time. Consider speaking with a reptile veterinarian if infertility issues persist. Remove any decaying infertile eggs promptly to prevent bacteria growth.

Conclusion

Identifying fertile leopard gecko eggs properly takes some patience and know-how. But armed with the information in this guide, you should be able to confirm which eggs contain developing embryos. This allows you to focus your attention on the viable eggs and prepare for healthy hatchlings.

Within several weeks, your diligence will pay off when you meet the next generation of healthy leopard geckos.