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I asked this in another thread but I think it's a good idea to talk about it so it gets its own new topic!
How often do you do this? Do you do this ony affter the adults are 'conditioned' by weeks and months of fattening up on frozen bloodworm?
Rob's rainy season is pretty well documented. Does anyone use paramters other than those?

Yes, ma'am.

I have my doubts about how important cold water changes are to make zebra's spawn.
I have never done it and my zebra's already spawned three times.

How are the experiences with others?

Now that's very interesting, I had always assumed that the vast majority of zebra spawnings had been triggered by the simulation of a rainy season. I think that Ken W may have also bred his zebras without simulating the rainy season. Perhaps your zebras have got the hang of things and for other people with stubborn to breed groups some stimulation is required to initially get them going. Perhaps you inadvertently triggered them off by doing a large water change after a long spell of no water changes, this seems to do the trick as well sometimes.

I wonder if it might not always be necessary to simulate a rainy season with cold water and large water changes. Sometimes removing a power head can be enough, and I believe a drop in PH can trigger them as well. Pure speculations from my side though!

What happened when my lot started, was three things:

1.I removed a powerhead (not because I thought it would trigger them, but because I was thinking of/wondering about wether a noisy enviorment was good for them. If I put my ear to the glass I could tell there was quite a lot of noise in there. It might be interesting to hear others view on loud vs quiet enviorment, but that's for another thread)

2.The PH dropped in my tap water, and it took a day or two before I caught on and corrected it.

3.I got a new cave for them that might have been more suitable.

I had been doing regular and heave water changes for as long as I'd had them, using colder water, but it wasn't until those three things happened that they got started.

Personally I'm thinking it might have been removing the powerhead and replacing it with a smaller but more quiet, and also lower capacity, pump, (much less current) together with the lowered PH that might have triggered them.

I've tested this on later occations, and found a female in the Alphas cave a week after having had a strong power head going for about three weeks, then removing it. It was a false alarm though, so I can't draw any conclutions from this.

HI Adam,

your correct. I was able to spawn mine without simulating rainy seasons with temperature drops.

I routinely perform 20% weekly water changes with the same temp. The current flow has not changed in the tanks. The only thing that could have contirbuted to them spawnig in my mind is a pH change, like what McEve mentioned. Occasionally I've seen the pH drop after a day from water changes and this was the lack of alkalinity in my mains/tap water.

One thing I plan on trying is dropping the hardness in my tanks to see if this helps in the number of hatching fries. Whenever the female spawn I usually see around 10 eggs but by the time they hatch the numbers drop to 3 or less. My regular city water hardness is around 300ppm and would like to drop it between 100 to 150ppm.

KenW, sounds like you could definately do with an RO unit to decrease your waters hardness . You should then see improvement in your hatchrate. If you don't mind me asking, how many breeding groups do you have and how many fish in each group?

Adam,

I have 2 breeding groups. 1 dominant male to 3 females along with a few younger zebras. Eventually I will move the younger zebras out in a better growing environment.

I believe barbie has a good point about better conditioned males not eating as many eggs. Reason is one of my males started breeding within 2 months of getting him. The entire group with the male was rather young, only 2 to 2.5 inches. I was planning to grow them for another 6 months to a year before attempting to spawn them. I didn't get a chance to condition him properly before he spawned so he isn't as robust. He seems to be the one that eats more eggs. Of course this is still a theory.

That is funny!

Like Barbie, mine also spawned the first time during my holiday.
I think that one import trigger for spawning is to be left alone.

Barbie wrote:It might also be that males that are in better condition don't simply eat as many, also. Who really knows?
Barbie

That makes sense. A hungry male would be easier tempted to eat an egg than one with a nice fat reserve to consume while he guards the eggs.

KenW, they bred at a size of only 2 . 2.5 inches..? I get confused about inches, but isn't that about 5cm? I didn't think they were mature at that size?

Have I misunderstood inches and centimeters, or are they really mature at that small a size?

Hi ,
With regards to eggeating, How can we be sure that the males are eating fertile eggs.
I currently have Sturisomas (Royal whiptails) breeding in my plec tank . I have found that the male only eats any unfertile or bad eggs . The water has a GH of 7 or 8 and only have approx a 50 % hatch rate. Another breeder ( who I got my stock from) who has them in a GH of 2 or 3 has nearly a 100 % hatch rate

KenW, what is your GH and KH in your breeding tanks?

Regards,
Des

We know that wild animals will sacrifice their young if it means survival of the others. On this background one can assume that a hungry male would rather eat an egg or two, to make sure he can stay the distance, than risk leaving the eggs to eat and risk loosing all.

But you're right Des, we don't know that they do it, and now that I found Zebra's can se IR light I'm out of ideas as to how I can spy on the male to find out about this - and other things.... what a bummer that was

Have you tried light in another range? Blue bright LED for example?