Reptile & Amphibian Forums

is there any way to tell if an egg is fertile? i posted previously about one of my female box turtles dropping eggs randomly about the pen.. i have since moved the turtles (who were being quaranteened) into the pen with the rest of my herd... for the last three days i have found three eggs (one a day) deposited on top of the substrate. after the first time i have made an area that should be suitable for laying but they have apparently declined using it.. i have heard that if they dont bury them then they probably arent fertile.. but how would the turtle know? they are definitely breeding constantly and have been since i put the males in with the females about 4 months ago.. i am wondering why they are laying eggs so close to winter (although i do live in georgia, so its still quite warm here).. and if there is any point to incubating them... until i have an answer about the fertility of the eggs i am going to keep them in a makeshift incubator .. its a 2 1/2 gallon acrylic aquarium. i put a small tub of water with a bubbler in it to keep the humidity up (its around 80%) and there is a 25 watt light that keeps the tank around 82-85. the eggs are placed in the position i found them in moist eco earth and sphagnum moss. thanks in advance..
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my pets: clown treefrogs, reed frogs, big eyed treefrogs, tiger leg monkey frogs, gray treefrogs, milk frogs, cuban treefrogs, whites tree frog, green treefrogs, squirrel treefrogs, blue webbed gliding treefrog, red eye treefrogs, chameleon treefrogs?, mossy treefrogs, dusky salamanders, tiger salamander, box turtles, mud turtle, map turtle, yellowbelly slider, florida softshell, two saltwater tanks, five cats, two chinchillas, and a boyfriend.

Most of the time a fertile egg will set or become more solid as opposed to an infertile egg that remains soft and the consistency of dried jelly. Some can appear fertile but the embryo has died shortly after egg laying. Also infertile eggs will usuallly appear translucent while fertile eggs firm up and appear chalky.

It is true that gravid boxies will lay infertile eggs on the surface; however some will lay fertile eggs on the surface for a variety of reasons. Stress, high heat, not having a proper nest site, or small enclosure are among the many reasons which can cause a boxie to lay eggs on the surface. Even a diet deficiency can cause boxies to laid eggs on the surface.

To know if your eggs are fertile you can candle them; but there are differences in candling bird eggs and reptile eggs.

Ric K.

See the link from a previous post on candling below.

Link

I incubate by the old rule never give up on an egg unless you know for sure it wont hatch.
infertile eggs after a month or so of incubation turn brownish, generally get hard and sunken in, while the fertile eggs are white, firm but still soft and usually seem like they double in size within the first few weeks.

Rouen,
I was under the impression that you used candling with your eggs.... as you posted.

"I Candeled , I Saw" at:

http://forums.kingsnake.com/view.php?id=1140288,1140288

Did those that you candled not turn out OK?

Hopefully they made it; if your light was a cool light.

But I totally agree with you to keep the eggs incubated until it's obvious they are dead.

Ric K.

yes I candle I didn't start candling till after it was obvious the one was not fertile the other 3 eggs were the ones that hatched and gave me the 3 beautiful little ones that are happily wandering around now.
I dont think I will ever candle again though, after I'd check them I'd always worry about moving the egg or sudden increase in temp... I think next time I'll just stare at them and bite my nails.

"I think next time I'll just stare at them and bite my nails."

That's hilarious! Yes, and sometimes it is helpful to mutter little curses at them...it really gets them cooking! My personal favorite after they hatch is, "Eat, you little flippin' moron!" Yes, and I do say "flippin'". Thank you for making it PG, Napoleon. Works like a charm.

I wish I saw that post before. My pair of boxies always lays eggs each year. Some have been fertile some not. However, the ones i've incubated always die or stop developing after a couple weeks. My guess is that I was candling them wrong. I never realized your body temp could kill them or that the flashlight I was using was prob too bright. I have three eggs left in my incubator from the five she laid. One stopped developing and the other three i'm not touching till plenty of time goes by. Thanks for posting that link.

Your welcome...

Most boxie breeders know that boxie eggs should never be turned; but many do not know that boxie eggs are very sensitive to quick temperature changes, such as the 98 degree heat from our hand, or the sudden raise in temps from the use of a bright flashlight, or that the oils from our hand can adhere to their extremely porous shells. ...Causing the egg to have problems with absorbing moisture for proper growth.

When I candle; I don't need to even move the egg. I just use the fiber optic attachment made for looking down gun barrels with a 90 degree bend in it. It's gives a bright cool light. I just scrape some substrate away from the end of the egg and place the light there. I can candle a dozen eggs in 3 minutes. That's why I still have my nails!

Ric K.

great.. that was quite helpful.. i think ill just wait and see what happens.. does the temp and humidity im keeping them at sound ok? or should i go and try to find an incubator? i really dont want to move them until i know one way or another if they are fertile.. also... i was wondering if you could tell me what the best type of nesting site consists of.. maybe she isnt happy with what i provided.. thanks again
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my pets: clown treefrogs, reed frogs, big eyed treefrogs, tiger leg monkey frogs, gray treefrogs, milk frogs, cuban treefrogs, whites tree frog, green treefrogs, squirrel treefrogs, blue webbed gliding treefrog, red eye treefrogs, chameleon treefrogs?, mossy treefrogs, dusky salamanders, tiger salamander, box turtles, mud turtle, map turtle, yellowbelly slider, florida softshell, two saltwater tanks, five cats, two chinchillas, and a boyfriend.