Danios don't get pregnant. Pregnant is a mammalian term and refers much on internal fertilization. Gravid is the better term when you are referring to fish but this applies only to internal fertilization which is achieved by livebearers particularly mollies.
As danios are egg layers, "ripe with eggs" is often the better term for that. There is a chance they will lay eggs soon. If you have a spare 5 gallons tank, put some tankwater in it by half level of the tank, then place 3 layers of marbles in it for substrate. Since the eggs are heavy, the half level of water will allow the eggs to fall faster and slip inside the layers of marbles thus preventing the danios from consuming them after they fertilized the eggs while on the go.
After they are done with that, put them back to the main tank and dose the tank with Methylene Blue. This will prevent development of fungus on the eggs. Pls use sponge filter for the 5 gallons tank. Other filters will not be advisable as they have the tendency to suck the eggs and even the fry.
While waiting for the eggs to hatch, prepare to hatch some brine shrimps. If not, try to buy a liquid-based food in your lfs. Egg yolk from hard-boiled egg which is then suspended in a jar of water will also work. Take care not to overfeed. Feed the fry once they are free-swimming. They are not in free-swimming stage for the first few days so you have plenty of time to prepare the foods needed.
Take note: Do so if you're really planning to breed and raise the danio fry.
Your blue danio looks stunning.:thumbsup:
Scientific name: Brachydanio kerri
To add this, danios are one of the easiest cyprinids to breed.:wink2:
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