Coral Red Pencilfish

The Coral Red Pencilfish is a beautiful ornamental tetra that comes from South America and is mainly distributed in Peru. This fish, which grows to about 4 cm in length, belongs to the family of slender tetras and is mostly calm in its kind. The black vertical stripes offer a nice contrast to the sometimes very intense red basic colouring, which makes it a great eye-catcher.

Care in the aquarium

Due to its higher maintenance requirements, the Coral Red Pencilfish is classified as moderately difficult and rather not suitable for beginners. Nannostomus mortenthaleri should be kept in an aquarium with a length of least 60cm and should be kept in a group of at least 10 animals (ideally with more females than males) for it to feel comfortable. In groups that are too small, it can be much more fearful and shy. Socializing with very lively animals is not a good option as the Nannostomus is easily intimidated and withdraws. However, calm bottom dwellers such as Corydoras are very suitable as tank mates. The tank should not only have enough space, but also be well planted and structured to offer the animals a place to retreat if necessary. Care should also be taken to ensure that the water is nitrate-free, clean and soft. Keeping the Purple Pencilfish in a blackwater tank is ideal and you should not go without regular water changes, as this fish is quite sensitive to pollution and suboptimal water parameters. These fish feel particularly comfortable in a tank with dense vegetation, which offers enough hiding places, but also enough swimming space. Floating plants are also welcome in the aquarium, since the Purple Pencilfish is mainly found near the water surface and likes to hide between the roots of the floating plants.

Feeding

In its natural habitat, the Coral Red Pencilfish feeds on small worms and crustaceans, insect larvae and approach food. In the aquarium, it is optimally fed with small amounts of live and frozen food, but will also accept fine dry food.

Sexual characteristics and breeding

Males are often bright red between the black longitudinal stripes, while females are more yellowish. However, identifying the sexes based on coloration is not always possible or meaningful, since the dominant males in particular show this red coloration, while suppressed males can take on the coloration of the females. Females can be identified by a straighter anal fin and do not have the white spot seen on the males’ dorsal fin. For breeding, fine-leaved plants should be present in the tank, between which the females spawn. In order to increase the fish’s willingness to spawn, more live food is fed and the tank is darkened. The water should also be very soft, rather acidic and, above all, clean. After spawning, the eggs should be transferred to a separate breeding tank or the adults should be removed from the tank, since dwarf ornamental tetras are spawn predators and do not stop at their own offspring. After about 1-2 days, the dwarfs hatch and, after the yolk sac has been consumed, can be fed with infusoria, copepods and newly hatched Artemia nauplii. For healthy growth of the young fish, the water should be cooler.