Black Widow Tetra

Black Widow Tetra (Gymnocorymbus ternetzi)

The Black Widow Tetra, also known as the Black Skirt Tetra, is a hardy and eye-catching community fish known for its flowing fins and dark, smoky-grey body with distinct black vertical bars. Originally from the slow-moving rivers of South America, particularly in Paraguay, Brazil, and Bolivia, this peaceful schooling species is perfect for beginner and experienced aquarists alike.

Black Widows typically grow to about 5–6 cm, and do best when kept in groups of 6 or more in a peaceful community aquarium. They thrive in well-planted tanks with open swimming space, gentle water flow, and stable conditions. Ideal parameters include temperatures of 22–28 °C, a pH of 6.0–7.5, and soft to moderately hard water.

Feeding is easy—they readily accept high-quality flakes, micro pellets, and frozen foods such as daphnia and bloodworms. Their active schooling behavior and dramatic contrast in coloration make them a dynamic visual addition to any tropical setup.