I can't really tell by your picture but females will be larger and have a more rounded belly than males and the male, when is good condition and wanting to breed, will have a red nose while the female will not.
This is how to breed them:
There are 2 methods people use for spawning (single pair or group spawning.) I prefer to set up single pairs unless you are doing this in a large area or vat for the fry.
For single pair spawning, you want to seperate the males from the females so that they cannot see each other for about 2 weeks. In this time you should be conditioning them for spawning by providing plenty of food and a clean environment.
My spawning tanks have usually been 10 gal. tanks even tho these are smaller fish. You'll put in only the following: I suspend a piece of eggcrate that's big enough to cover about 1/2 of the tank. Cut it to size so that the fish cannot get underneath it. You'll cut a seperate piece to form an L shape to block the entrance from the front. (I usually use some PVC connectors in the corners and the middle of the piece to support the eggcrate.) You want to attach some bunches of live thick, small leafed plants (ie Anacaris, hornwort, cabomba, etc) so that the area above the eggcrate is well planted. You want a heater in the tank set at 78- 80 degrees and an airsrtone only (no filter!) You'll be using all new water so cycling will not be an issue.
That's the set up. ( You can see a diagram of the setup in my albums in the "instructions" album.) You may also want to put a cover over the tank as Barbs sometimes jump out of the tank when spawning. I have also used large marbles on the bottom instead of eggcrate but found that the percentage of fry went up using eggcrate because the parents couldn't get to the eggs at all whereas with the marbles, I've watched them dig in for the eggs.
After conditioning the breeders, place them both into the spawning tank and try to stay out of site. I usually put my breeders together about 2 hours before the lights went out. In the morning, you should see eggs underneath the eggcrate or amongst the plants. Remove the breeders at this point. (If you don't see eggs but the female is thinner, remove them and you can assume that they spawned in a thicker part of the plant area.)
If you haven't seen signs of spawning within 3 days, try another pair. If you still get no spawning, you need to dig deeper into the water parameters you are using.
The live plants will act as both a nursery and an infusoria innoculater. You'll still need to produce some infusoria cultures to feed the fry. When you see the fry are at the free swimming stage, replace the airstone with a sponge filter. This will be your setup until the fry are big enough to move to your grow out tank.
That's the basics for breeding most of the smaller barbs.
For group breeding, you'll need to create a planted "pen" in which you will place the breeders so that the eggs can fall into the tank. The pain with this is that you'll need to figure out how big the pen needs to be only by trial and error. You'll be separating the sexes between each try. This is why I prefer the single pair method.
So those are the basics. Feel free to PM me if you have any further questions
Hope this helps
