A zebra danio is ready to lay eggs when you see her midsection bulging with lots of little circular protrusions. They will get very large and chunky. When the male starts chasing the female a lot, it also usually signifies that the female is ready to lay eggs.

The breeding box will prevent adult fish from getting in and it will initially hold the pregnant female guppy until she releases the fry, after which she is extracted, and the fry are kept safely in the breeding box.

Just Leave Them with Their Parents What they’ll do instead is eat them, decimating their numbers. Some juveniles may be able to hide if you have a thickly planted aquarium, at least until they grow large enough not to be mistaken for food anymore.

When the mother gives birth, the babies fall to the bottom of the tank, secluding them from both the mother and other fish and ensuring that most of them aren’t eaten. Some fry may still swim back up to the top of the tank, so this is not a completely safe method. It is, however, the easiest approach.

If you are keeping your fry together with the adults, in the community tank, you don’t need to worry about your water parameters. As long the adults are happy, the fry will also thrive.

How long do you keep fry in the breeder box? In general, the babies should be large enough to not fit in mouths of the adult fish before you add them back into your main tank. For livebearer fry, this may be as soon as 4 to 5 weeks.

Size. Before you can move your baby guppies into your big tank, they need to be large enough that the other fish won’t eat them. Exactly how large depends on the size of the fish in the main tank, but the minimum size the babies should be before you move them is about an inch long.

African cichlids, which are maternal mouthbrooders, are an example of fish that continue to protect their young even after the eggs have hatched. Female African cichlids hold eggs in their mouths for 21 to 36 days. During this time, the female does not eat, leaving no opportunity for an egg to escape.

Mouthbrooding species

• Cichlid.
• Apogonidae.
• Ariidae males carry a clutch of a few dozen eggs in their mouths, all of them about the size of golf balls for about two months before they hatch.
• Luciocephalus pulcher.
• Jawfishes.
• Osteoglossid are all mouthbrooders.
• Gourami.

Coelocanth