Taxonomy
Weitzman, 1978
Family: Lebiasinidae (Pencilfishes),
subfamily: Pyrrhulininae
Order: Characiformes (characins)
Distribution and habitat
Found in the area of the Rio Capim near Belem in the town Badajos, in near the estuary of the Amazon.
Kullander also found it together with Nannostomus digrammus and Nannostomus limatus close to the city Santarem.
Stawikowski (2006) reported on an import from Fortaleza (Ceara), about 1200 km southeast of Belem.
My Experience
I keep a large group in a 160 liter tank.
There are often some disputes among the males, but never seriously violent.
They have never bothered the Apistogrammas living in the same tank; the dwarf cichlids live near the ground, and the pencilfish live near the surface. I have never seen them taking any fry from the Apistos, either.
They eat everything I offer...
Breeding
I keep a large group in a 160 liter tank, with a thick layer of floating plants covering most of the surface.
Here they spawn, and I see quite a few fry in different sizes among the floating plants, most of the time.
Enough fry grow up not only to maintain the group, but also to produce a nice surplus.
Thanks to the work performed by the English gentleman and Master breeder of tropical fish, Alan P. Vaissiere (1934 - 2012), we now know how to "produce" more specimens, if needed, under more controlled conditions:
SPAWNING LOG
FISH Nannostomus nitidus
TANK 12"x9"x8"
SET UP Sponge filter + one floating mop
WATER R/O, some boiled and poured over alder cones and added to tank till tea colour
PH 6/6.2
DH Under 1
TDS 007
TEMP 79
DATE IN 13-8-11
DATE SPAWNED 15-8/11
DATE HATCHED Started hatching after 48 hrs
FREE SWIMMING 20/8/11
FIRST FOOD 20/8/11 Infusoria
2 Pairs were set up in separate tanks the same day.
DAY1 both pairs swimming about but no sexual activity.
DAY2 same again but Alan realized that the pair that had spawned a few weeks before were split so the males were changed over, and within 1/2 hour sexual activity was observed and the pair that had previously spawned did in fact spawn. The mop was removed to a receiving tank, and the mop was replaced.
DAY3 the same pair spawned again so mop again replaced. The other pair, although active, no eggs were laid
DAY4 both pairs laid eggs. Both mops removed and replaced. The first eggs started to hatch.
DAY5 the pair that had been spawning did so again. This time the mop was removed to another receiving tank, to see if after the 4th time the eggs were still fertile. In the hatching tank a couple of fry were now hanging on just like splinters on glass.
DAY6 The same pair laid again. Mop removed. As the other pair have not lain, they were removed
DAY8 The pair laid again. Then they were removed, as Alan had learned what he set out to do.
SUMMARY
This species has proved to be a period spawner.
Some articles state that they are not very prolific. When someone states this it usually means the species is period spawners. If you put into a breeding tank period spawners and remove them in one or two days having seen spawning activity, you wont get much, will you, as they lay a few eggs each day over a period of days.
So the trick is to harvest, one method is pointed out above.
They lay quite adhesive eggs, and they place them into the mop, they don't scatter them (as N. beckfordi does).
Another interesting thing is that they may be a little selective in choosing their mates (This fits with articles describing them a little more difficult to induce to spawn than N. becfordi).
One good point about period spawners is most don’t hunt their eggs. They will eat any they do see but wont actively hunt as some of those that scatter their eggs do.
We do not know how long the spawning period for this species is, but as stated above they were still laying after 8 days, and these last ones were also fertile.