A large quantity of frogspawn  appeared in our small garden pond at the beginning of March. A couple of weeks later most of this is clearly well on the way to developing into tadpoles, but the first batch now contains an opaque white dot where each black egg was. I don't think I have missed the 'hatching' as the white dots appeared only a few days after the spawn was laid so I wonder if this is a fungus or the eggs were defective in some way. Could it have anything to do with the unseasonably warm and sunny weather we have had in the southern England over the last few weeks? Any explanation would be welcome. Many thanks.

Hi There,

You are right, when the frogspawn has a white, not a black centre, that egg has died.  It might be a fungus that has attacked it, but I would guess that the change in colour is due to the breakdown of the proteins, pigments and other material in the egg, which has failed to develop.
I hope this helps to answer your question.

Frogs often lay a number of infertile eggs too, they can be used as food for growing tadpoles or as extra protection (or both). It is unlikely that a fungal infection has affected this change...