Ideal conditions for the reproduction of this species are as follows: general hardness of around 2 degrees, pH 6. 8, temperature 24°C ( 75°F). If you have the opportunity to test the water with a conductivity meter, the conductivity should ideally be around 30 microSiemens. After the spawning is over the fish should be caught, and the procedures as described above for Nannostomus marginatus should be followed, never forgetting to darken the tank. At a temperature of 24°C ( 75°F), after about one and a half to two days, the young should hatch from the eggs, and after another four days they can begin to be fed. The fry of this species are larger than those of Nannostomus marginatus, and they can be given freshly hatched Artemia, Panagrellus, and mashed algae straight away. While raising the fry of either species, it should be remembered that after about 14 days from their first feeding, the waterparametersshouldbegin to be changed gradually, moving towards those in which the adult specimens are kept. After a month, as they keep growing, the young should be moved to a bigger tank. Both species reach sexual maturity at about six to seven months of age.
Wild-caught Nannostomus mortenthaleri may be difficult to wean onto prepared foods, but it
can be achieved over time.
A breeding pair of Nannostomus marginatus, female above, male below; the pair should be
placed in the spawning tank the night before actual breeding is predicted to occur.
For the imaginative hobbyist,
reproduction of these species can bring to
mind experiments in a sterile medical lab,
and hobbyists should not be discouraged
if at first they are only able to raise a few
members of the next generation. After some
more attempts, one can probably obtain a
few dozen or so, which will be a major
success and well worth boasting about to
other hobbyists. The reproduction of these
species would surely be a challenge for any
The fish will reward their keeper for
their care with their beautiful colors,
which appear at their best against the
background of a dark bottom and lush
greenery, when the fish are kept in groups
numbering from about a dozen to a few
dozen specimens. These species are very
good for community aquaria and, due to
their small size, do not need large tanks.
Very often they are merely an addition to
planted tanks, but their interesting biology
makes it worthwhile to keep them in a
species aquarium, or with other members
of their genus. D