Black Darter Tetra (Poecilocharax weitzmani)

The Black Darter Tetra is a peaceful and shy fish. Unlike the majority of Tetras, these do not form into large shoals. Males are aggressive and territorial towards each other. Although it is achievable to keep a pair in an aquarium, it is better to keep them in a small group of one or two males with several females to reduce bullying.

The Black Darter Tetra is challenging to maintain and is best kept in a single species biotope tank. It should contain a soft, sandy substrate, some branches and driftwood roots to provide cover, some dried leaf litter to maintain the pH and floating plants for shade.

The Black Darter Tetra is a small elongated, slender-bodied fish that has the disposition of a Dwarf Cichlid and resembles a killifish. This fish has a pale orangy-brown body colour, with a strong black lateral band with neon blue holes that run from the gills to the caudal fin.

Habitat

Found in blackwater, freshwater rivers in the upper regions of the Rio Negro, Rio Orinoco, Rio Inirida, and Rio Solimoes river basins and the Casiquiare canal in Brazil, Colombia, Venezuela, and Peru in South America.

They inhabit very soft, acidic waters that are most commonly found in slow-moving rain forest streams with sand or mud substrates, an abundance of decomposing leaf litter and plenty of submerged trees.

These rivers are typically in tropical rain forests where the thick jungle canopy provides permanent shade and shelter, and the discharge of tannins and organic acids from decomposing plant matter stains the water a dark tea colour.

Other Tetras of interest

Diet & Feeding

In the home aquarium, these fish are somewhat challenging to feed. Live foods are almost obligatory, but most fish can usually be persuaded over time to accept frozen bloodworm.

Black Darter Tetras will not eat any motionless food. They will accept live microworms, daphnia, brine shrimp, grindal worms and chopped bloodworm, but are notoriously reluctant to eat freeze-dried or flake foods.

Sexual Dimorphism

It is relatively easy to distinguish females from males. Mature males are considerably more colourful and slightly larger than females, and their dorsal and anal fins are more extended than the females. In contrast, the females are duller, their fins are shorter, and they are smaller than the males.

Breeding

Black Darter Tetras are rarely bred in an aquarium environment. However, it has been accomplished. They require very soft, acidic water, with plenty of hiding places such as rock caves, flowerpots, or pieces of PVC pipe. This is where they will lay their eggs.

You will need to condition these fish by feeding them small live foods to encourage them to spawn. When ready to spawn, the female will become darker, and the anal fin will turn an intense red colour. The male's colours become more intense, and the edges of their pelvic fins will become white and thicker.

The males will select single or multiple caves as their territory and protect them from other males. When the developed female is ready to spawn, she will swim into the male's territory where spawning will usually occur within a couple of days.

The female will deposit 50 to 100 eggs on the inside roof of the cave which the male will guard. The male will refuse to eat until the eggs have hatched, which is usually around 4 to 5 days later.

The fry becomes free-swimming approximately two days after hatching and can be fed with newly hatched baby brine shrimp. Once the fry is swimming freely, the males will stop caring for the brood, and they will need to be removed, or the parents will consume them.

Because the male refuses to eat during the brooding stage, it is essential to feed him with plenty of live food. During the incubation period, it is not uncommon for males to spawn with other females.

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