Two years ago my children took part in the Japanese tradition of goldfish scooping. If you search for "goldfish scooping" on the internet you can get the full details of what is involved, but it is a very common activity at summer festivals here and basically consists of trying to scoop baby goldfish out of a big container with a paper scoop. You can keep scooping until the paper breaks and then you get to take home the goldfish that you scooped in a plastic bag. For details on the history of this event etc. one good site is here.... wikipedia goldfish scooping
Of course most small children have trouble doing this, but you are usually given a fish even if you don't manage to scoop it, which is exactly what happened to my children a couple of years ago. Anyway, the tiny fish are now quite big fish and as it turns out there is one male and one female and the female keeps laying eggs while the male chases it around and around until it is too tired to move any further and goes and hides in the tunnel or behind the pump. We were excited at first by the prospect of showing the children how the eggs hatched etc and raising the fish, but the adult fish always ate all the eggs before they hatched. So....(sorry this story is getting longer than it needs to be!) I decided to remove a few of the marbles from the tank that had eggs stuck on to them just to see if they would hatch and low and behold when I looked in the bowl just now there are about 6 very, very tiny fish swimming around. I doubt that we will be able to keep them alive, but it will be fun trying. Any hints from experienced gold fish raisers welcome!