Why bubbles in water

Question
Hi Tom Lee,

I just bought 8 Lionheads goldfish yesterday and I realized that there are a lot of bubble-like on the water surface (something like sliver but with bubbles), is this normal or are they eggs?  

How do I know if they are eggs lay be the female?

Pls. advise.

Thank you!  

Answer
Hi Bernard,

It's probably just air bubbles being forced up to the surface. Goldfish are egg-scatterers so any eggs that are laid would float to the bottom of the tank or be stuck to leaves. It's also pretty difficult to get Goldfish to breed in captivity without the necessary know-how

Tom