[Zbrafish] Re: Breeding zebrafish

Tyrone via zbrafish%40net.bio.net (by tgenade from gmail.com)
Fri Apr 11 03:10:15 EST 2008

Hello Wenyan,

> ...We are having big problem with our fish breeding...
> fish facility: pH around 7.3-7.6, Conductivity around 250-300, and
> Temperature is a little higher (29C)... But they simply don't lay eggs

Your temperature is too high for breeding. This is how I used to spawn
my zebra danios in large numbers (to feed to other more carnivorous
fish fry).

1. seperate the males and females and condition them for 3 days.
2. prepeare a tank with either marbels on the bottom or a fine plastic
mesh that can seperate the eggs from the fish (which will not hesitate
to eat the eggs). You want about 5 cm of water above the mess or
marbels. A fine mesh with 5 mm pores works best in my opinion. 1 cm
below the mesh is fine.
3. in the evening bring the males and females together (2 males per
female) and then do a 50% water change with cool water. A drop in
water temperature stimulates spawning. 10 deg C drop is perfectly
fine. The water temperature must not exceed 24 deg C for breeding. The
next morning the fish WILL spawn.
4. remove the fish after spawning and you can take out the plastic
mesh too.
5. keep doing 50% water changes on the spawning tank or pour the eggs
off into an incubator that will ensure that they are kept well
oxygenated and in clean water. Some people suggest the use of anti-
fungal or anti-bacterial agents to protect the eggs but most of these
are DNA intercalating agents and I have always gotten away without
using them. Clean well oxygenated water seems to be all you need to
ensure high egg survival.

For the record, I do not work with zebrafish in any professional
capacity now or ever but for almost 20 years I have kept and spawned
them in pretty good numbers.

Best of luck


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