The Miniature Nannostomus (Nannostomus anduzei) also known to tropical fish keeping enthusiasts as Anduzi’s Naqnnostomus and Miniature Pencilfish, is found about 20 kilometers north of Puerto Ayacucho in Venezuela’s upper Orinoco river basin. It has also been collected from one other area several hundred kilometers farther south in the rio Ererê drainage, a minor tributary of the middle rio Negro basin in the Amazonas state, Brazil.
The Miniature Nannostomus is a peaceful, shoaling, species that is the smallest member of the genus, and although relatively common as a by-catch among shipments from Manaus, are rarely available in large numbers to tropical fish keeping enthusiasts.
Nannostomus anduzei are collected in extremely shallow and slow moving perennial forest streams (called Caño Provincial) over sandy white substrates, with submerged roots and leaf litter. The Caño Provincial originates from a freshwater spring surrounded by Mauritia flexuosa (the Moriche Palm) and flows about 2000 m into a wide, shallow lagoon next to the Rio Orinoco. The lagoon has turbid water, with a mud substrate that supports both emerging and floating vegetation.
In December of 1984, when the species was originally collected, the water chemistry of the Caño Provincial had a pH of 5.0, and a water temperature of 80.6°F. The water in the lagoon where Nannostomus anduzei was also collected among the plants was 86°F, at a pH between 5.0-7.0. None of the fish were collected from the surrounding acidic black water habitats however, the Brazilian rio Ererê fish were collected from a black water biotope, with all males possessing longer anal fins.
The Miniature Nannostomus is a very small fish. They become sexually mature at less than .5 inch and achieve a maximum length of only .63 inch as fully mature adults. Despite their diminutive size, they are a strikingly colored species.
They have a golden brown body with a metallic gold stripe that runs the length of the body along the lateral line. They have patches of brilliant cranberry red on their anal and caudal fins.
Males have a longer anal fin, with some of the surrounding muscle modified to enable mating, are slimmer bodied, and are more brilliantly colored around the red patches on their anal and caudal fins, especially when in breeding condition.
Females can have a brighter metallic gold body stripe than males but the red patches on their anal and caudal fins are always less brilliant and somewhat paler compared to males.
Although they can be housed with other small fish such as Paracheirodon simulans (which it is sometimes exported with as a by-catch) in a small community aquarium, it’s small size and timid nature makes the Miniature Pencilfish particularly suited to a nano aquarium environment.
Place as many as you can acquire, or at least 10 individuals, in a densely planted aquarium of fine leaved plants of at least 15 gallon capacity, with a dark sandy substrate, some floating plants to diffuse overhead lighting, driftwood for the fish to hide among, and some Indian Almond Leaves or other leaf litter to promote the growth of microbe colonies. The decomposition of the dried Indian Almond leaves releases tannins and other beneficial chemicals into the water and establishing a secondary food source for the tiny fish.
Miniature Nannostomus need a lot of free swimming space and clean, aged, slow moving water conditions in their aquarium, which makes a good filtration system and frequent water changes mandatory. Gentle filtration with an air powered sponge type filter should be adequate.
Although breeding Miniature Nannostomus is not reported to be easy, they have been bred in an aquarium environment. Their eggs are laid and fertilized between the leaves of fine leaved plants. After spawning, the parents should be removed from the breeding tank and after three days, the eggs hatch out. The fry should be fed fine infusoria when they become free swimming and freshly hatched baby brine shrimp or finely crushed omnivore flakes as they grow.
Nannostomus anduzei is an omnivorous micro-predator that in their natural habitat feed on small worms, invertebrates, and zooplankton in the water column. In an aquarium environment, their small mouths and overall size require small portions of crushed flake foods, and daily offerings of live, frozen, or freeze dried brine shrimp, tubifex, microworms, grindal worms, Moina, etc. They reportedly browse on algae and biofilm which may represent a significant portion of their diet.
Miniature Nannostomus are almost never intentionally exported from the wild for sale to tropical fish keeping enthusiasts however, occasional specimens do turn up as a by-catch with other species, primarily from Manaus shipments. They can occasionally be found for sale online, but almost never in tropical fish shops.
Minimum Tank Size: 15 gallons
Care Level: Moderate
Hardiness: Moderately Hardy
Water Conditions: 75-83° F, H 18 – 90 ppm, pH: 5.0 – 6.5
Max Size: .5 – .64″
Color Form: Brown, Gold, Red
Compatibility: Nano- tank
Origin: Venezuela, Brazi
Aquarist Experience Level: Intermediate