Coral Red Pencilfish (Nannostomus Mortenthaleri)
The Coral Red Pencilfish is a small, striking freshwater fish known for its vibrant red coloration and elegant pencil-like shape. They are peaceful and relatively shy, making them an excellent choice for community aquariums with other calm, small fish species.
At their adult size, Coral Red Pencilfish only grows to 1.25 inches. They are very peaceful but do not make an ideal community fish due to their small size and rather timid nature. They are better suited for aquariums with other tiny, non-aggressive species, such as Green Neon Tetras, or on their own.
Coral Red Pencilfish are outgoing extroverted fish with a shoaling nature, meaning they prefer congregating in loose groups rather than moving in unison like schooling fish. During the day, it is common for male Coral Red Pencilfish to engage in friendly competition, which can sometimes result in nipped fins within the group. However, this behavior typically doesn't extend to other tankmates. Keeping at least 10 or more Coral Red Pencilfish together is recommended, as larger groups help disperse aggression and encourage the fish to exhibit bolder and more natural behaviors.
These fish also make excellent dither fish for Apistogramma species and other dwarf cichlids, as they typically occupy the middle-to-upper regions of the tank and do not prey on fry.
Their diet consists of small live or frozen foods like brine shrimp, daphnia, bloodworms, and high-quality flake or micro pellet foods. Supplementing their diet with a variety of foods will help maintain their vibrant coloration.
To create a comfortable habitat for Pencilfish, provide a well-planted aquarium with a dark substrate with subdued lighting to enhance their colors. Include hiding spots using driftwood, rocks, cavies, and plenty of live plants to mimic their natural environment. Pencilfish tends to swim in the middle and top regions of the tank; the addition of floating plants offers an additional sense of security and diffuse light. Pencilfish also requires a spacious aquarium, and their décor arranged to create plenty of broken lines-of-sight to reduce aggression between males.
These fish thrive in soft, slightly acidic water with a moderate water flow. Use a gentle filtration system; an air-powered sponge-style unit is generally adequate and performs regular water changes.
Coral Red Pencilfish is generally found in the middle to upper levels of the tank. They require clean, stable water conditions with a pH of 5.5-7.0, a hardness of 2-12 dGH, and a temperature of 75-82°F (24-28°C). A minimum aquarium size of 20 gallons is recommended, while a 30-gallon community tank would be ideal for these fish.
A well-fitting tank cover is also necessary, as Coral Red Pencilfish may jump when startled.
Introduce these fish into a mature, stable aquarium environment to ensure their health and well-being.
To learn more about this fish, be sure to check out the Additional Information tab.