Schrödinger's Chick: Is it Alive or Dead? (candling eggs)

[Josefina]

I have 7 shipped hatching eggs under broody hens right now; 3 cochin eggs and 4 d'uccle eggs. I candled at day 11, and all but one of the d'uccles looked perfectly normal. (I use this Candling Progression post to reference if my eggs are looking normal/healthy.) The one d'uccle egg appeared to have not one but three large black spots (like an eye spot) arranged in a crescent shape. I also could see no veining, and the air cell has a strange shape, possibly from shipping trauma. Since it wasn't clear like an undeveloped or barely developed egg I decided to leave it a few more days before deciding to pull it.

Today I candled again--day 15 development--and everyone looked normal except for that one. I was planning to pull it today if it looked the same as it did on day 11 (I've never had an unhatched egg explode in a nest before, but I've read too many horror stories of it happening, and now I'm paranoid). However, the egg does look different when I candled--just one big black spot now instead of three. Still no sign of veining though, and the dark area isn't as big as in the other eggs, which are mostly dark now from being nearly filled up with chick. I saw some movement in the egg while candling, but I think it may have just been from me turning it to view different angles.

Has anyone seen this before and found out what was going on (either by eggtopsy or the chick hatching)? Any help/advice on what to do with mine? I've never seen this phenomenon before so I'm not sure how to handle it. I'll feel horrible if I pull the egg now and find out it was a viable chick, but like I said, I'm also paranoid that it could explode or somehow contaminate the other eggs it's with if I leave it.

 

[oldhenlikesdogs]

Put it back. Eggs shouldn't explode at 21 days. If it isn't good it won't hatch generally, and you get rid of it on day 22 or 23.

 

[Josefina]

Thanks!
Since I've never had the exploding egg experience personally, I stuck it back under the broody after candling this morning.

 

[Josefina]

Hatch Update: 6 of the eggs hatched on days 20 and 21 with no problems; the 3 Cochins and 3 D'uccles!

After one last candling on day 22, I went ahead and opened up the 4th D'uccle egg. I cracked the shell over the air sac and started peeling it away (of course I forgot to take pictures). It was really fascinating getting to see into the air sac (slightly saddled) and see the inner membrane separating it from the chick/yolk/innards. Then I pulled off the inner membrane and spilled the contents into a bowl. I was guessing it was a day 10ish quitter by what I saw candling, but it turns out my guess was off--the embryo looked like it was a day 5 or so quitter. Poor little thing! It was a dark pink crescent, complete with black eye spot, about the size of my pinkie finger nail. The yolk looked like it had gotten scrambled up with the egg white, but the yolk membrane may have only broken when I emptied it out of the egg. There wasn't a single vein to be seen in the yolk or any of the membranes. It smelled kind of weird, but not bad like a rotten egg. I'm still not sure why development stopped, but at least now my major curiosity is satisfied as I know what was inside.