Xingu Black Neon Tetra Care Guide - Aquarium Setup, Diet & Breeding

The Xingu Black Neon Tetra is a small, streamlined characin with a silvery body and a strong dark lateral marking that gives the species its distinctive black-neon appearance. Depending on mood and lighting, the dark stripe may be accompanied by subtle metallic or bluish reflections, while the fins remain mostly transparent with delicate colour at their bases.

This is an active but peaceful schooling fish. In a suitably sized group, the tetras spend much of their time moving through the middle levels of the aquarium, displaying to one another and settling into a confident, coordinated shoal. They are generally peaceful toward similarly sized fish and are not equipped to compete well with large or aggressive tankmates.

In the wild, the species comes from warm tropical waters within the Rio Xingu system, where submerged branches, leaf litter and aquatic vegetation create a complex backdrop. These habitats can range from clear to lightly stained water, with cover helping small characins avoid predators and navigate the current.

Moenkhausia heikoi is less commonly encountered than the familiar Black Neon Tetra, Hyphessobrycon herbertaxelrodi, and should not be confused with it. Its compact size, attractive dark flank and South American origin make it an appealing choice for aquarists seeking a less usual schooling tetra.

Moenkhausia heikoi is native to the Rio Xingu basin in Pará, northern Brazil, South America. It occurs in tropical tributaries and forested waters associated with the Xingu drainage.

A group should have at least 60 litres, with a footprint of approximately 60 by 30 cm or larger so there is room for uninterrupted swimming. Use a dark, fine-grained substrate with driftwood, branches, leaf litter and live plants arranged to provide shaded retreats while leaving open water at the front or centre. Gentle filtration, subdued lighting and floating plants suit their woodland-stream character, while a secure cover is advisable because these active tetras may jump.

Up to about 4.5 cm (1.8 inches) in total length. Females may be slightly larger and deeper-bodied than males.

They are omnivorous micro-predators that feed on small aquatic invertebrates, insect larvae, crustaceans and other tiny food items in nature. Offer a varied diet of quality small flakes or micro-pellets supplemented with foods such as baby brine shrimp, daphnia, mosquito larvae and finely chopped frozen foods. Small portions fed regularly are easier for their small mouths to manage than large pieces.

Xingu Black Neon Tetras are peaceful community fish and can be kept with other calm, similarly sized species. Suitable companions include small Corydoras, pencilfish, peaceful small rasboras, other gentle tetras, Otocinclus and non-aggressive dwarf cichlids such as Apistogramma when the aquarium is appropriately arranged. Avoid large predatory fish, fin-nippers and boisterous species that may intimidate or outcompete them, as well as fish large enough to swallow them.

Xingu Black Neon Tetras are egg-scattering characins that spawn among fine-leaved plants or spawning mops. Condition a group with plenty of small live or frozen foods, then introduce the adults to a separate breeding aquarium with soft, slightly acidic water and subdued lighting. Spawning usually takes place among the vegetation, after which the adults should be removed because they may eat the eggs. The eggs hatch in roughly 24 to 36 hours, and the free-swimming fry require infusoria-sized foods before progressing to newly hatched brine shrimp.

Females are usually fuller through the abdomen, particularly when carrying eggs, while males tend to be slimmer and slightly more streamlined. Differences can be subtle outside breeding condition.