Blood spots are from a blood vessel breaking when ova is released from follicle.
Meat spots are from a tiny piece of tissue breaking loose from the reproductive tract.
I think it's explained in this excellent video, which is worth watching regardless, tho it's about chickens not ducks I assume...
Hmm not sure....only thought is 'dead' blood turns dark.
What do you mean the shell has a grey tinge?
Do you know what duck this egg is coming from?
Right, but thought ducks might be exposed to different habit and diseases.
I remember you posting it before...
....not sure where or if there was any resolution as to what it was.
Did you start a thread about it, or was it stuck into another thread?