Genus name: Gymocorymbus
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,
Water: soft and slightly acidic water
Lives: In the middle and upper areas of the
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.
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