Upon purchase of these fish, I contacted the breeder, Greg Niedzielski, and received the following email, that he gave me permission to share on this forum. Thanks Greg.

The flammeus are fairly easy to breed. I bred them in regular Buffalo tap water, which is pH 7.4 and 150ppm, so your water should be fine. Optimum temperature would be in the mid seventies.  I bred them over sifted and boiled peat moss placed in a small Tupperware container. They don’t dive too deep, but they will scatter the peat in the tank. I incubated the eggs at room temperature for 3 months or so, and hatched them again in regular tap water. I fed them brine shrimp as a first food, but I’m sure they’d eat infusoria and microworms as well for the first couple of days. They grow fast and will be sexable in 2-3 months. They have more red on them when young, but when they mature the male will have nice extensions on the unpaired fins, like a constanciae.

I fed the adults frozen brine shrimp with the occasional feeding of bloodworms as a treat. They also like live blackworms. Most killies aren’t too keen on prepared foods, so I never fed them anything like flake food. They don’t seem too susceptible to disease, but with all my annuals I put ½ tsp. of sea salt per gallon just in case they get Velvet.

Good luck with them, they are a very nice little pearlfish! Feel free to post this.

I have young adults now!  Gorgeous fish. However, they are all males.  Any ideas on what effects sex ratio in N. flammeus?

Thanks Kris,  I have another batch that just hatched. I'll try to keep smaller fry separate.  By the way, my pH is about 7 - 7.5, hardness about 120-140 ppm.  Temperatures about 74-79 F  since the room is heated.