Black widow tetra

Care at a glance

Overview

Give them a group of six or more in a tank of about 75 liters and they'll occupy the middle. They're mostly peaceful but can nip fins, so skip slow, long-finned tankmates. They handle a wide range, from the low to mid 20s C and a pH from slightly acidic to neutral. Feed flake, micro pellets, and frozen bloodworms or daphnia.

In the wild

Black widow tetras come from slow rivers, streams, and flooded forest in the Paraguay and Guaporé basins of South America. Those waters are soft, slightly acidic, shaded, and full of roots and leaf litter. They don't demand a strict biotope, but a planted tank with some cover and a darker substrate suits them well.

Good to know

A member of the family Characidae, this tetra grows to about 6 cm with a tall, flattened body and dark vertical bars. The black tends to fade to gray as fish age. They are egg scatterers with no parental care. Conservation status is Least Concern.

Did you know

The dyed and long-finned versions sold in stores are the same species, just tank-altered. The injected colors fade over time, and the dyeing process is hard on the fish, so the plain wild-type is the better buy.

Related species

• 

  Diamond tetra

  Moenkhausia pittieri

  2.4 in (6 cm)20 gal (75 L)75–82°F (24–28°C)

• 

  Bloodfin tetra

  Aphyocharax anisitsi

  2.2 in (5.5 cm)20 gal (75 L)72–82°F (22–28°C)

• 

  Red eye tetra

  Moenkhausia sanctaefilomenae

  2.8 in (7 cm)28 gal (105 L)72–79°F (22–26°C)

• 

  Blue tetra

  Knodus borki

  2 in (5 cm)22 gal (85 L)72–79°F (22–26°C)

• 

  Emperor tetra

  Nematobrycon palmeri

  2 in (5 cm)20 gal (75 L)73–81°F (23–27°C)

• 

  Glass tetra

  Moenkhausia oligolepis

  2 in (5 cm)18 gal (70 L)75–82°F (24–28°C)