as lots of people know in here, google helps alot. hope this helps:
Ideal for beginners, as they are prolific breeders. Zebra Danios are somewhat unique, as they are quite loyal to their chosen mate. Mated pairs remain together, and rarely spawn with others, even if one mate dies.
The breeding tank should be set up with shallow water, approximately six inches deep. Furnish the tank with fine-leafed plants or a spawning grid on the bottom. Course gravel works well, as the eggs will fall between the gravel pieces and will be protected from the adult fish, which will readily eat their own eggs.
Spawning requires temperatures of up to 78 degrees, and can be triggered by raising the water a couple of degrees near dawn, when spawning normally occurs. 300 to 500 eggs will be scattered across the bottom and on the plants. Remove breeders after spawning, as they will consume the young.
The fry will hatch in two days. They are very tiny, and can easily be lost when changing water, so take care when maintaining the grow-out tank. Feed the young commercially prepared fry food, or finely crushed dry foods. Powdered egg may also be added to the fry food to promote growth