They sure aren't darts...but a group of firebellies would be neat to watch...and I have some Endler Live Bearers in the water portion of the paladarium...having some "sunning rocks" that could be covered in a low growing moss would be a good spot for the firebellies...Since the firebellies have some toxins on their skin, make sure to not handle too much...they don't bother the fish at all. I have emerging plants, part under, part over the water...you have to consider how you could feed crickets to whatever frogs you choose...they drown pretty quickly unless they have a land mass...good luck...love the spillway for the waterfall...keep us posted