Peruvian Red Pencilfish (Type II) "Nannostomus mortenthaleri"

Care Level




Reef Compatible


Plant Safe


Max Size

Less than 2"

Minimum Size

20 gallon


Black, Purple, Red, White



Water Conditions

Soft (2 to 10 GH), slightly acidic (4 to 7 pH), 72-83 degrees Fahrenheit

General: Lifespan of up to 5 years, reaching a length of up to 1.5". Should be in a tank size of 15 gallons or larger. The Peruvian Red Pencilfish is social, active, and are willing to occupy every niche of the aquarium. Should always be in groups with a 1:2 male to female ratio and will create shoals.

Fecundity (Reproduction): Female will produce 20 to 30 eggs per clutch. Pre-feeding high quality foods during the period before actual egg dispersal can increase fecundity, as well as promote health of eggs.

Habitat: Forest streams and wetlands near Rio Tiger Basin located in Peru. This region has many tributaries densely packed with driftwood, vegetation, and fine rocky debris. A natural companion of the Dwarf Cichlid genus Apistogramma.

Aquarium Diet: Spirulina, brine shrimp, baby brine shrimp, blackworms, zooplankton, and general flakes

Dimorphism: Male will laterally produce a deep red color and have a white patch on the anterior end of the dorsal fin. The male will also turn a darker red, or even purple, when ready to breed. The female will be significantly less red in coloration and be thick-bodied in comparison to the male.

Peruvian Red Pencilfish (Type II) Photo Gallery