• Scientific name: Poecilocharax weitzmani
• Synonyms: -
• Common name: Black Darter Tetra, Black morpho tetra
• Group: Characins
• Habitat: South America; Brazil, Colombia, Peru and Venezuela in the Amazon Basin, upper Orinoco River and upper Rio Negro.
• Size: 4 cm
• Biotope: Found in slow-moving blackwater streams in the rainforest with sandy or muddy substrate. These waters are tea-colored because of the dried and decaying leaves on the substrate.
• Social behavior: A generally peaceful and shy fish, but males can be agrressive and territorial to each other, and shouldn’t kept with other substrate-dwelling fishes such as dwarf cichlids. Keep with small, peaceful fish, which swim in the upper water regions. Male forms a small harem with 2-3 females.
• Diet: Carnivorous; Mainly eats small invertebrates and insect larvaes in nature. Usually eats only live foods in aquarium, but occasionally accepts frozen foods too.
• Breeding: Hard
• Tank: Minimum 40 litres
• Population: 1 male and 2-3 females for 50 litres
• Decoration: Use a river sand substrate, and add some driftwood branches or roots. The tank can be decorated with dried oak or beech leaves. Provide hiding places among bogwood, stones and floating plants. Use dim lighting.
• Temperature: 21-28 °C
• pH: 3-6.5
• Hardness: 0-5 NK°
• Lifespan: 3-5 years

Description: Black Darter Tetra has pale yellow-brown body color with a bold lateral black line running from the gills to the caudal fin, which has a neon-blue shine. Rarely exported in large numbers because of its delicate nature, and often imported as unidentified by-catch in cardinal tetra shipments. It's not recommended to beginner aquarists! Fish from Colombia and Brazil are often more intensely colored. If there are more than one male in the aquarium, it is recommended to allow at least 30x30 cm territory for each of them, as territorial fights and serious fin damage can occur if there are not enough space. Poecilocharax weitzmani has small elongated and slender body that resemble to a killifish, and by behavior it is more similar to a dwarf cichlid.

Males are more colorful and slightly larger than females, and also have extended dorsal and anal fins as they mature. Breeding of Black Darter Tetra in aquarium is rare, but possible. Provide hiding places and acidic (pH 4-5), very soft water for them. Males will select a territory with one or more caves and defend these against other males. Plastic pipes and flower pots can be used as caves. Before spawning the fish also intensify in color: pelvic fin tips of males become white, and females get a dark appearance with red anal fin. When the female gets ready to spawn, she swims into the male’s territory and spawning takes place a few days later. The eggs are deposited on the roof of the cave, and the number of the eggs can be 50 to 100, which are guarded by the male. The eggs hatch in 4-5 days and the fry become free-swimming after another 2 days. It is not unusual that the male spawns with another female during the incubation period. The free swimming fry are large enough to accept Artemia nauplii, and it is recommended to put them into a separate tank, lest the parents eat them. The male does not eat during broodcare.