The body of both sexes is ochre, with silvery sides and a brownish back, which in males usually have numerous glittering metallic scales.

The fins of males intensify in color when they are excited, and depending on their mood, they can show more or less strongly a black band along the side.

[7] Males can also be told apart from females because their anal fin's front part splits off and transforms to a blunt, flexible andropodium used for mating.

The females become sexually mature at about six months of age and can give birth every six to 10 weeks according to the water temperature and the condition of the fish.

Mating is preceded by a courtship, where the males present themselves to the females with their heads pointing downwards – up to 45° from horizontal – and shake the forward part of their bodies.

[6] The fry when born can be up to 0.8 in (20 mm) in length, as the females feed the unborn young via trophotaenia which have a similar function as the umbilical cord in humans.

Butterfly splitfins are strong swimmers and social fish; they dwell in groups of three to five males and three to seven females in large tanks where they can grow to full size.

A. splendens breeds quite readily in the aquarium; some floating plants such as Ceratopteris or Ceratophyllum provide protection for young fry.

[10] They take live prey up to the size of week-old guppy fry, but need plant material, ideally green algae, to thrive.

In summer, they can be kept in outside tanks, basins, or small ponds in temperate and warmer areas; they can tolerate overnight air temperatures of 60 °F (15 °C) well enough, but should be protected from birds, cats, and other predators.