Zebra Finch Egg Fertility?

[Coturnix Quail]

So, my zebras layed an egg. And I incubated it probably one week or so. Now, I candled it, but instead of seeing a heart or veins, I see small circles. I place the egg right on the flashlight, and the circles move themselves! What are these and is the egg fertile?

 

[sourland]

It sounds as if what you are seeing are 'blood rings'. Indicating that the egg was fertile but the embryo died early on in incubation. Give it a little more time before tossing it.

 

[Coturnix Quail]

Ok thanks. My zebras haven't played a fertile egg in a while, I hope this is fertile. And even when they did they always tossed it out of the nest...