Genus name: Gymocorymbus Ternetzi
Also known as: Black Widow Tetra, Blackamoor, Blackskirt, Butterfly Tetra, Petticoat Tetra
Distribution: Mato Grosso area of Rio Paraguay and Rio Negro
Length: up to 2.4″ (6cm)
Water Temperature: 73-79F (23-26C)
Diet: Worms, small crustaceans, insects, dried food
Water: soft and slightly acidic water preferred
Lives: In the middle and upper areas of the aquarium
The Black Tetra is an excellent aquarium fish that is particularly attractive when young. In juveniles the Black Tetras flanks are black, but they become smoky-grey with increasing age.
The back of the Black Tetra is olive-green, the abdomen is whitish with a silvery sheen, and behind the gills there are two prominent black bands. Most Black Tetras have short fins, but it is also possible to get long-finned varieties.
As with other tetras, the Black Tetra male is slimmer than the female, who has a much plumper, rounder body. They should also be kept in groups of at least five, as they do like to shoal together.
Black Tetra are great for novice aquarists, as they are hardy, are tolerant of others and do not require any special treatment. They are also relatively easy to breed.
When it comes to mating time the male Black Tetra will swim around the female with fins spread out, sometimes in circles, or sometimes following a zigzag pattern. The tiny transparent eggs are laid at random among the plants, preferably those with feathery leaves. At this point the adult Black Tetras should be removed as to prevent them eating the eggs or young. The young Black Tetras hatch in 24-36 hours, and are free swimming three to five days later.