I have successfully spawned near to a dozen batches of pearl danios.
They are extremely easy to breed. Here is how I do it:
5g tank with heater, sponge filter, bare bottom covered with a
single layer of glass marbles.
Large clump of java fern stuck in between the marbles.
I condition the water with prime, run the sponge filter and heater
overnight for 80F.
In the morning the following day, I select 1-2 plump females from
my breeding stock, and 2-3 males per female of my most colorful,
I put the fish in the 5g tank. That afternoon late, just before dusk,
I do a small water change. Then I replace the water taken with
conditioned water of 5 degrees cooler temperature (75f).
I slowly sprinkle this water over the surface using a small watering can
with a many holed spout I purchased specificaly for this purpose. This simulates
a cool rain.
That night I pull the blind up a little in the window nearby, to allow the morning
sun to hit the tank.
I leave the adults in the tank for 48 hours, during which they will spawn frequently.
I then remove the adults and play the waiting game.
Within about 3-5 days of removing the adults, I check the tank with a flashlight
and can usually find the wigglers have hatched, and have risen out of the marbles
onto the glass sides of the tanks.
I do not change the water at all during the time from spawning to this time.
Once I see the wigglers become free swimming, I add an apple snail from another tank to this tank. The apple snail will serve 2 purposes, it will produce infusoria for the fry to eat in the first couple of free swimming days, and it will clean up any excess food in the tank.
The day they start free swimming I make up fry food by crushing staple flake food + HBH 8 veggie flake + freeze dried bloodworms, into
a fine powder, and I start feeding a tiny pinch 4-6 times a day. I will feed the babies on this food for about the first week to 10 days of the fry’s lives.
I monitor the fry daily and remove any that are belly sliders or deformed and feed them to my adult fish.
After the baby fry move up to the just finger ground flake foods, I start doing water changes. I do 20% water changes 2x weekly until the fry are about 3-6 weeks old, or about 1/2 inch in length, then I reduce my water changes to 1x weekly and reduce the feedings to the normal 2x daily for my adult fish.
By the time the fry reach 3/4 of an inch, or about 6-8 weeks of age, I move them in with their parents to a 25g tall tank.
I have used this method successfully to spawn both pearl danios, copper rasboras and hopefully soon will adapt this method with spawning mobs to raise blue eyed rainbowfish.
I hope this info helps you and good luck! Dont be afraid to try! Danios are probably the easiest egg laying fish to start experimenting breeding/fry raising with, and are easy to raise because they are a fast growing, relatively large egg hatched fry.