Freshwater butterfly fish are small, no more than 13 cm (5.1 in) in length, with very large pectoral fins. It has a large and well-vascularized swim bladder, enabling it to breathe air at the surface of the water. It is carnivorous, feeding primarily on aquatic insects and smaller fishes.
The freshwater butterflyfish is a specialized surface hunter. Its eyes are constantly trained to the surface and its upturned mouth is specifically adapted to capture small prey along the water's surface. If enough speed is built up in the water, a butterflyfish can jump and glide a small distance above the surface to avoid predation. It also wiggles its pectoral fins as it glides, with the help of specialized, enlarged pectoral muscles, the ability which earned the fish its common name. When freshwater butterflyfish spawn, they produce a mass of large floating eggs at the surface. Fertilisation is believed to be internal. Eggs hatch in about seven days.