One of my favorite killifish, Aplocheilus lineatus is an exception as it's
not shy, and it's fairly common. It can sometimes be found in your local
fish store as "Golden Wonder Killie." But it's also large enough to gulp
down copious amounts of fry. I have kept them with apistos with no problen,
but not in a breeding situation. A slightly smaller killie that can be
easily sourced from a killie nut is Epiplatys dageti. It, too, hangs near
the surface and is peaceful.