The two Zebra Danios that I have had for almost 2 years (the others died off within the first five months and I never replaced them) recently have been having fry.
Right now I see about 7 or 8 of the little buggers (damn their cute) swimming around in the tank.
The tank is only a 20 gallon, hasn’t been taken good care of (you should see the algae in my tank.) I want the little buggers to live as I couldn’t fathom killing them off for any reason.
Okay here’s are my questions:
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One of my fish books says to keep a light on pretty much 24/7 for the little guys. They offered no explanation and I haven’t done so. Why would they need light 24/7 when in the wild they don’t. The fry seem to be fine.
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The tank is in dire need of some water. It’s about 1/4 down from the top and I want to add water but I am afraid of shock for the fry. Should I wait till the fry grow more? The concern I have is that the female (I assume she’s the female) still seems to be fat from the eggs that she needs to release. So if I throw more water in there, could it disrupt not only the fry but the eggs had she already laid them? Also, should I add distilled water rather than treated chlorinated water instead?
Okay, sorry there are a lot of questions. I was really waiting till the two adult fish died then I was going to dismantle the tank because I don’t seem very good at keeping fish. Now I can’t do that. I need to get back on scheduled cleanings, testing water, etc…especially now that I have baby fish to tend to.
Your help is appreciated.
I’ve never seen a book recommend leaving the light on all the time. no wonder you have so much algae. I have mine on a timer, light is on during the day, off at midnight, on at 10am.
Put the water in a container and let it sit for 24 hours before putting it in the tank. this will help some of the chemicals in the water to breathe out and the temperature will be close to the tank temperature. If you have any water conditioning chemicals, you can use them.
If the fry are really small, you might want to isolate them so they don’t get eaten.
Joey, I have no means to isolate them. The father seems intent on eating the fish food, he goes bonkers. I 'spose I should feed half as much twice a day instead of the old feeding of once a day to keep mommy and daddy from eating the kidlets.
Oh, and the algae is because I suck at cleaning tanks and only have the light on about 12 hours a day. If I recall correctly, Danios are in fresh water in regions closer to the equater (as most fish in tanks are) and have more light.
If you saw my tank, you’d be amazed that any fish are alive at all. But somehow, some way, these are very hardy fish.
I’ve raised hundreds of zebra danios; there are even some websites that tell you how to do it production-line style (they are used in science labs for genetic studies). The parents will eat the fry if they can catch them or get really hungry depending on their size.
Now how big are the fry? They hatch out about the size of a ! mark, litterally. If the fry are that size, they are more sensitive than say 5mm long. They probably only survived (found enough food) BECAUSE your tank is dirty… lots of microscopic critters living in the algae/gravel/mung around the tank. You can transfer them to another container, just fill it with water from the tank. However, they will most likely starve to death within days since there will be no little nerbies swimming around to eat. If the babies are large enough to eat ground up powdered flakes, that’s better. The 24/7 light thing is most likely to encourage algae(and it’s associated tiney zooplankton) growth. I assume the fry are large enough to show some zebra danio markings and look like just really small fish… around 0.5 to 1cm? They are fairly tough at that size as compared to newly hatched.
A better solution would be to remove the parents to another tank, and let the fry continue growing. If there is no other tank, find a divider (peice of glass, plastic canvas, well plastic anything really) to split the tank in two - just make sure everybody is on the proper side. Danios are probably too frisky to keep in a breeding box and would jump out, unless it is big. The best choice is to keep the fry in the tank since they are growing and finding food.
A 25% water addition probably wouldn’t hurt them (never hurt mine), but to minimize the shock you could add some chlorine remover (usually containing sodium sulphate of some kind), and warm the water up to the same as tank temp. Distilled water would only be needed if your city water has chloramines or other nasty stuff in it and you want to fill the tank right now. The distilled will have a different pH and hardness than the other water though. Tap water should be fine, treat it to be safe.
If there are only 7 or 8 babies, it means that around 200 didn’t make it. If you want more, you can put the parents in a smaller tank with marbles or a screen on the bottom. They will spawn there, but not be able to eat the eggs. If the female is still fat, she hasn’t laid many if any eggs. Don’t worry about disturbing zebra danios from spawning - they are remarkably horney, and like to be in groups so they can have little fish orgies that would put anything on the net to shame in only a couple inches of water if need be!!