I think you should try some new foods especially live food. Also, sex separation for one to two weeks helps the fish respond for spawning.

Hi Shanchun,

I think that, the crucial point is temperature. You should keep fish at the different photoperiod 12 hours of light and 12 hours of night. I used this light regime for Black Molly (poecilia sphenops) since years and they have no break in reproduction at winter time.

best regards,

Hanna

8L:16D photoperiod for zebrafish spawning ?

The general photoperiod for zebrafish is 14L:10D in papers(someone uses 12L:12D). If you keep the temperature and water quality(pH, conductivity and nitrate..), you can't find the reason easily. But you may find  wether the water quality or in-breeding is causative of bad production if you breed outside zebrafish in the same system. For your reference, zebrafish do not chage production rate according to season based on 7 year experience.   

I always find a cold water change with RO/rainwater followed by a feed of quality live or frozen food (daphnids and cyclops work well) helps to restimulate regular breeding by egg scatterers 

I agree with Matthew. A water change with water at 2 degrees cooler will generally do the trick and serve as trigger for the breeders to spawn. However one needs to condition the broodstock by feeding them good quality dry food and live food for a few days as suggested prior to placing them in the breeding tank, preferably separating the sexes too. A photoperiod of 12h:12h is suitable.

"We follow basic roles such as adjust light cycle light 8hr and night 16 hour"

Shouldn't you do the opposite ?

Temperature sounds fine.  The current light cycle commonly in use is 10hours off and 14 hours light.  This was changed from the traditional 12:12 cycle to mimic the light cycle during peak breeding season in the native environment.

In my experience water quality can be important both in their regular environment and the mating environment.  We typically use dividers to control initiation ( not critical for performance) of breeding in the morning and freshen the water as soon as possible in the morning.  There have been many times when someone has told be their mating is not working and changing the water helped.  The water can become foul overnight if more than a single pair is set up together.

The feeding strategy showing the best results is usually a combination of live and dry diet.  We currently use brine shrimp once a day and Zeigler adult diet twice a day. 

I was previously at the Mayo Clinic in Minnesota where the seasons change quite dramatically and it seemed like the onset of winter had a negative impact on breeding but this is anecdotal.  The effect (if real) was temporary however.   I do not really seem to experience the same here in San Francisco where the temperature is moderate all year long.

Certainly quality husbandry during development is an important factor in long term fecundity and this will be more critical when you are mating mutant lines.  Age is also important with fecundity beginning to drop with animals over 1 year.  We usually rotate animals off the system by 18months.

Poor results are a factor of animal health and/or environment.  It is a matter of seeking the essentials of good animal health and avoiding extremes in environmental factors.

Ah. Sympathies! I hate when that happens. A few things to add to the good advice already given:

Check that the light cycle timers are working - ours was once set for 14/10 but stuck "on", and that devastated breeding cycles for a while. Same can happen if someone's there at 'night' opening the door and disrupting the dark period.

Another thing you could try could be to tilt the mating tank inserts so that the grating lies at an angle - the zebrafish like to spawn on the shallow "beach" end, almost out of the water. Sometimes that helps when mine won't lay. You could also try autoclaved plastic plants or marbles to give the mating tanks some more natural features, and make sure there are plastic plants in the adult aquariums if there are only a few adults, because they're sometimes stressed/bullied by dominant in that situation.

I don't know how chubby the females are, but if they haven't laid it a while you could try gently squeezing them, perhaps they're eggbound? Also, how old are the fish you're using?

Goodluck!

Maria has a good point... older females may be egg bound or have an increased possibility for mycobacterial infection which may also lead to a potential for egg binding.  Also older "slender" males may be unhealthy or mycobacterial infected as well. Do you routinely screen sentinel fish for mycobacteria or other pathogens? Hysto-pathology may provide clues.

Oh, I am sorry to hear that.

As for condition for fish, we use 28.5°C with a 14-hour light/10-hour dark cycle. It works well.

As for mating without eggs, I am wondering how often did you cross them?  

I'm agree with Maria.