Sexing Zebra Danios?

[Seacon]

Hello,
I have recently started long tail zebra danios in my aquarium, somewhere down the road, breeding sounds like a good idea, with that in mind, how the heck can I tell these guys a part?
I read some where on the internet that females look silver-ish all over, while the males look yellow between stripes. Well, all of them looked pretty much the same all silver too me, so off to the LFS. For some reason (lighting, water quality) they all had a yellow tint. They are still in my quarantine tank and the others are in my normal tank. So, I haven't done a side by side yet, but they seem pretty close, the newest seem a little yellow tinted on the fins but that's it.
The other way of sexing is body shape, I heard that the males are longer, slimmer, and females shorter/fatter. I have one that fills that bill and leads me to believe, that the yellow stripe is not true or much harder to see than I understood. Oh a addition is, I heard that the females are the bosses, of the older zebras, the chubbier one is pretty much in charge even over larger zebras.
So, can anyone fill me in?
I also heard that these fish mate in selected pairs, so I may end up with a tankful of lonely guys! (Better than being the one female guppy in the tank would be though!)
Hope that wasn't too rambling,
Thanks for any info,
E

[yashinfan]

Alright, I'm a self proclaimed pro in this area. In the pet store, the danios have not been properly conditioned so it is quite difficult to sex them. If you feed them with frozen or fresh brine shrimp twice a day for ~3-5 days you will be able to tell which sex is which. Females have more of a tummy, a rounder underside. Males are usually longer and skinnier, their bottom-underside fin is more yellow. That's where they are reffering to. This site: http://mike-edwardes.members.beeb.net/Drerio.html show a picture of a male and a female beside eachother and makes it easier for you to note in the future. If you have any further questions, do not hesistate to ask :)

[Seacon]

Thanks for that quick reply, I'll try that feeding tip out, after seeing your pics, I'm very confident that the body type sexing will be correct, and I'll only have 1 female!

Thanks again,
Eddie

[Seacon]

Well, it seems like it worked out for me. I still can't really see the yellow under fin of the males, but body shape does work nicely. My wife also noted that it seems like the males are completely striped and that the females are not towards the bottom, to make the tummy stick out a little more easily. Looks like the group of five is now 3 boys, two girls. (The three in quarantine didn't make it! Water seemed fine, so I'm a little more cautious of the new LFS I got those three from!)

Thanks again,
Eddie

[yashinfan]

Glad to hear it worked out! My problem was with finding males! I ended up with 3 males and 7 females when I was trying to get 5 and 5. With my fry, I'm seeing an overwhelming number of females as well! As for the deaths, that is a little weird. Now the only thing I can think of was a dramatic change in pH. So if you didn't introduce them to the new tank slowly enough they could go into shock or be over stressed. That would kill them in ~30 mins. If it took longer then it could be a problem.

[Seacon]

Yashinfan, you are indeed correct! Poor little guys, it was indeed pH. For some reason, a bacteria bloom appeared shortly after, and the pH was extremely low. So I cleaned that up, raised the pH, and guess what; another bacT bloom! It's pretty milky looking. Anywho, I'm currently working on getting that tank straight, it's clearing up now, so anymore fish are on hold till it's running cleanily (and over time!).
The shrimp made everyone a little plumper, so I think they are all females now. j/k. I'm still sticking with 2 females, but only one is positive in my mind. Everything is going well in the 20 g tank.
No sign of fry yet. Could my powered filter be sucking them up without leaving me any sign? The last filter was very brown, but I chalk that up to the brine shrimp.
Oh, how often do you recommend using shrimp, I believe it was 2x daily (which is how often I feed now) for breeding. How about for general purpose (healthy and happy)? I have noticed them not eating the shrimp sometimes, instead wanting flakes.
Thanks for all the info.

[yashinfan]

Alright, lots to address!

First off, that answers whether or not your tank was cycled. Now, the weird thing is that I have NEVER had a bacterial bloom. :o I am the Queen of Impatience, and have yet to fishless cycle a tank. None the less, I have been good about adding fish slowly and so I have never had any problems.

Now, what I suggest is water changes!! 15-20% daily should do the trick to get rid of the milky water. Make sure to dechlorinate!

As for feeding and breeding: Mine get 2 meals a day. Hikari brand Brine Shrimp is their diet, complete with a very rare dose of newly hatched brine shrimp that are a pain to raise! *grr* So now the question is: what is your substrate?

They may have spawned without your knowledge and then consumed all the eggs. You need either a) large gravel/rocks b) marbles. After you see fry sticking to the sides of your tank (they look like 3mm black lines) you have to pull out all the adults. Sad to say but eggs and fry are also good conditioning food for the adults.

So until you get all that sorted out, ie: substrate, cycling, water changes, good diet, you should have trouble getting them to breed. But 77F/24C water temp, a pH of ~7-7.6 and good substrate and they are sure to pair up.


:) goodluck!

[Seacon]

Ok, to try and stick with some order here:

My little tank for quaranteen just does not want to clear up, water conditions are good, 0 NitrIte, less than 20 NitrAte, and a 7.6 pH. Just can't get rid of that milky look. No one lives there now, and won't till it finally clears.

The Zebras are in the 20 g, which has cycled basically the same conditions as above, and nice clear water. According to my test kit, I have medium hard water (11 GH) (4 KH). The water is clear and so far no problems.

Shrimp: I'm using the same brand, once a day. Flakes for breakfast:D

Substrate: Gravel, about 1 1/2 inches, should I put marbles over that? Will that affect the bacteria?
That's all I can think of at the moment, and thanks again!

[yashinfan]

Marbles over gravel would work, but you need a pretty think layer. I used over 3 litres of marbles for a 10 gallon. Now the thing is, that after the fry are free swimming, you should take out the marbles, otherwise your tank will have to be siphoned v. often and usually you will suck out lots of fish! Cloudy water is just a bacterial bloom that won't necessarily harm your fish. Now, did you check for amonia? Because that will harm your fish. Anyway, just keep doing 20% water changes and eventually the water will clear up and will be good to go!

[Mrsoftey2]

I think i got 1 male 1 female and the male is always chasing the female. should i do somthing???