I've a tank of these and once you know how to sex them it is quite obvious, except of course if you have the misfortune to only buy all females like I was.
This site will show the male and female, the top picture is the male, the bottom one which is not as dark and does not have as much red in the tail and anal fins is the female.
http
/fishaliciousfish.blogspot.com/2007/...earl-danio.html
They are egg layers and will seed them on floating or drifting plants, I put killi mops in my tank and then regularly remove them and put them into an incubation tank with an air line.
The fry are helpless for the first week or so and only feed on infusoria, after that time you can try them on vinegar eels and hopefully if they survive they can start to take microworm, it will be a month or so down the line before you can try them on brineshrimp.
The fry are really tiny, much smaller than any killi fry I've seen and can't swim initially, they lay on the bottom of the tank and can easily be predated on by their parents or other tank mates if the tank isn't well planted.
it took me ages to figure out what was happening to my fry in the adults tank, so once I realised how helpless they were I started using the above method, I now have a nano tank with around 12 free swimming tank
