Selecting pairs of fish

There is some discussion of how to tell the sex of goldfish elsewhere on this site. A brief recap:

Be aware that males will relentless drive females to exhaustion, so you need to make provisions to remove the female when spawning is done or to provide some shelter in the spawning tank. Also keep in mind that goldfish voraciously eat their own eggs, so you want to remove the spawning material (or the fish) once the action has slowed down.