Neoheterandria elegans

Lore & Background

Neoheterandria elegans is found in the Truando River in Colombia. The front half of the fish is mostly silver, while the rear half displays alternating gold and black vertical bars. Males grow to 2.0 centimetres (0.79 in) and females to 2.5 centimetres (0.98 in).

Like most poeciliids, it is a livebearer. The male uses a modified anal fin, or gonopodium, to deliver sperm to the female. The gonopodium of Neoheterandria elegans males has a long, bony rod that projects forward and downward, which distinguishes them from the genus Xenophallus, whose males have gonopodia that project either to the right or to the left. Unlike some male livebearers that court females, male Neoheterandria elegans copulate by thrusting their gonopodium at the female's vent.

Females do not drop their whole brood at once like guppies or swordtails; instead, they generally release between 2 and 4 fry each day for several days.

Reader's Guide

Neoheterandria elegans is relatively easy to keep in an aquarium, but the temperature must remain above 23 degrees Celsius. Unlike some poeciliids, this species tolerates soft water well. Due to their small size, they can be maintained in small tanks. Their unique reproductive strategy—dropping 2 to 4 fry daily over several days—differs from the single-brood release of guppies and swordtails. This behavior, along with their distinctive gold and black barred rear half, makes them an interesting choice for dedicated aquarists. The species is not as popular as other poeciliids, but its ease of care and tolerance of soft water contribute to its suitability for small-scale aquarium setups. The male's forward- and downward-projecting gonopodium is a key distinguishing feature from the related genus Xenophallus.

Did You Know?

• The male Neoheterandria elegans grows to only 2.0 cm (0.79 in).
• Females release 2 to 4 fry each day for several days, rather than all at once.
• This species tolerates soft water, unlike some other poeciliids.