Marble hatchetfish
These are fun fish. Tetras with a hatchet-shaped thorax. They are surface-dweller, though they can and do dive. As all tetras, they are schooling fish. When I purchased mine, the sales guy in the pet shop dropped one from about two meters high onto the stone floor. It has survived until this day. Tough little guy... They are jumpers however and should not be kept in open tanks. This also means they should not be kept in low-placed tanks, are you will not see them that way. They are the most manoeuvrable of fish - fun to watch, hard to catch.
They eat everything, though thier up-turned mouth has evolved for eating from the water surface. Make sure some of the food you feed floats. I have not bred these fish, but reportedly it is doable in the common tetra way: in soft, water water, with eggs to be trapped out of reach for the parents.