This material is from the 4th edition of The Zebrafish Book. The 5th edition is available in print and within the ZFIN Protocol Wiki.
Chapter 2 - Breeding
Method For Maximal Embryo Production
(Source: E. Sullivan)
This method requires more work, but is especially well suited for
production of large numbers of embryos (upwards of 1000 embryos per tank)
once or twice a week. A continuous supply of embryos can be obtained with this
method by adding more tanks of fish and rotating the schedule among the tanks.
Although zebrafish reach sexual maturity in 10-12 weeks, the breeding fish should be between 7 and 18 months of age for maximum embryo production. Keep males and
females in separate tanks with up to 8 females or 16 males per 10 gallon tank.
The tanks should be cleaned at least once per day by siphoning, replacing about
1/3 of the water. Feed the fish 2-3 times per day. On the day before you want
embryos, 1-2 hr before the end of the light period, feed the fish and clean the
tanks. Then transfer the males into the tank with the females at a ratio of 1 male
to 2 females (excellent results come from 4 males and 8 females). Add marbles
to cover the bottom of the tank a single layer deep. After the beginning of the
next light cycle, collect the embryos by siphoning the bottom of the tank (see Embryo Collection).
After collecting the embryos, transfer the males back into their tank, scoop
out the marbles with a net and clean them thoroughly by autoclaving or by
soaking them for 4 hr in a 10% solution of bleach followed by a 4 hr rinse in
running water. Do not collect embryos more than two days in a row from the
same fish and remove the marbles for at least a week between embryo collections.
Transfer all fish to new aquaria every 10 days and scrub and bleach the old
The Zebrafish Book