How big do black widow tetras need to be to sex and breed? And how do you sex them? And what type of setup do they need to breed?

females are slightly more rounded, males are thin

i spawnd them in my community tank a few years ago , they just did there own thing

I spawn them two days ago. Still not free swiming yet.

If you look at the bodies of the fish an igore the fins, you should notice that the females have a rounder shape, the males are more elongated.

I suggest a marble bottom tank because they like to eat the eggs. Also bunches of plants. They like to spawn around plants and objects.

Be sure to get up early to watch the spawning. It is cool.

How big do they have to be to breed?

mine wer this long lol -----------------

well im going to put the female in the tank now. Is it best to spawn them in groups or pairs? I only have one male that i can breed though. And as for fry food can i feed them something like this Novotom ? I was told to use this for breeding tetra.

I think that that Novotom will be TOO big. You will need to start them off on infusoria for the first week. Then week two infusoria and BBS.

I did my ones as a pair, and all good there.

How do i get Infusoria?

Search this site, you'll find lots of info on the subject.

I have decided that i will wait till my blackwidow tetras are bigger till i try breed them. So i went and bout what i think is a pair of long finned ones from petworld. They dont look too healthy though. They have really chewed up fins and are really pale. Will there fins grow back? And What is the best food to keep them healthy?

Oh and what is the best temp for them to breed at?

ok, so this morning i realised the female was half as fat as she was when i got her but couldnt see any eggs.i Just got home from school and there are heaps of eggs all over the ground. They are white, are they fertile or not?

if they're white they are unfertilised; if they are translucent they are good.

If they are unfertilised they would have turned white after being shed which would be why you didn't notice them this morning perhaps

Was there a male with her?

The fertile eggs are VERY difficult to see. You may have fertile eggs in the tank. Wait a few days to see if you got any fry. The fry are even harder to see than the eggs. They look like tiny slithers of glass.

I will put pics of the pair up tonight to confirm i have a male, But i think i do.

If i get fry,can i feed them liquifry?

I think so. But that sounds expensive.

liquifry is 1 drop for every 4L, 2 - 3 times a day, so you don't use a lot.

best thing i found is to mix the required amount with water in a small container first, then use an eye dropper to squirt it all through the tank. this way you can be sure it disperses properly and doesn't end up as a lump on the bottom.

if i do get any fry i will move them to a 13L tank as the eggs are in a 30L tank.to make it easier to feed.

Here is the photos of the parent fish.

First 2 pics are of the female and the last one is what i think is the male.

Ive got some fry now, and have been feeding them liquifry no1.

I cant see that many fry, probably because the tank is too big and there is still gravel and plants in there.

And i have set some BBS last night.

Question is When do i start feeding BBS?

After one week.

What is the best way to get the bbs from the bottle to the firy?And how long before you can feed the frozen brineshrimp, bloodworms and flakes?

I use a turkey baster

Do i have to filter the bbs through something to get the salt water out?