Great looking fish. I believe these are annual killifish. I'm looking forward to seeing how they reproduce for you in the tank.
I got some off ebay once. I wasn't as attentive at feeding the fry and cleaning the tank as I should have been, so only a couple survived to adulthood. I would like to try it again sometime and do things properly.I just noticed you can buy their eggs off ebay for $6.99 + shipping