Colombia, specifically the Rio Truando River of the Rio Atrato system, has been cited as the location where Neoheterandria elegans is found in the wild. This fish is endemic to Colombia and cannot be found elsewhere. It was first described scientifically by Henn in 1916, but was not introduced to Europe until 1988 (Mörth). It belongs to the family Poeciliidae, which tells us that it is a viviparous fish.
In my breeding, males grow to a maximum of 1.5 cm and females to 2.5 cm at maturity. However, on the internet we can also find the maximum size of males 2 cm and females 3 cm. Thanks to its very small size, it is an ideal fish for the so-called mini aquariums, which are so popular at the moment.
I believe that the species name ‘elegans’ was mainly inspired by the appearance of the females, whose basic colouration is golden-brown, with vertical dark stripes on the back of the body, while the fins are colourless. The males are coloured the same, but their very small size does not allow the elegant colouration to stand out, and so the most noticeable feature of the male is his gonopodium, which is quite large in relation to the overall body size of the fish.
Unlike most other species of the family Poeciliidae, which have young periodically at certain intervals, Neoheterandria elegans can be said to give birth essentially all the time. Females have 1-2 young every 2-5 days. This gradual maturation of the embryos is called superfetation and is known especially in the species Heterandria formosa.
The relationship of the adults to the juveniles could be described as ignorant. However, the problem is that the freshly born fish measure approximately 2-3 mm, so we have to offer them as little food as possible. In an aquarium that is densely covered with plants, the young will find plenty of hiding places and also food (swirls, algae). Pleasingly, they also accept freshly hatched nauplii artemia.
I got the six-member group of Neoheterandria elegans from Roman Slaboch – a person who perhaps needs no introduction to people who are at least a little interested in wild livebearers. I placed this group in a small aquarium, which had a volume of 30 litres. The aquarium was without substrate, the plants were represented by only one species, a large clump of Vesicularia dubyana. The company of the tiny animals was provided by the freshwater shrimp Neocaridina heteropoda. There was no technology in the aquarium.
Their diet consisted mainly of artemia nauplii, decapsulated artemia eggs, frozen cyclops and finely ground flake and pelleted food from various manufacturers – so it can be said that Neoheterandria elegans is not picky about food, provided of course that we provide it with food that is adequately sized or small. To my amazement, I have observed on several occasions how these small fish have been able to improve their diet with small shrimps. Their prey were juveniles up to one centimeter long, which they dug into until they had eaten the whole shrimp.
The fish in this aquarium thrived and grew, but I still didn’t get any young ones. After about half a year, I decided to move the whole group to another aquarium, which was equally without technology, but with a substrate consisting of Aquaclay, the vegetation consisted of a clump of moss Vesicularia dubyana and on the surface was Ceratophyllum demersum.
I don’t know if it was due to the temperature in the second aquarium, which at that time was 26 °C, two degrees higher than in the previous aquarium, the plants below the surface, or the absence of any “roommates”, but the truth is that after about a month these fish delighted me with their first offspring, followed by more and more after a few days…