Description
Scientific Name: GYMNOCORYMBUS TERNETZI
Common Name: Black Widow Tetra
Adult Size: 1.5 to 2 inches (3.8 to 5 cm)
Life Expectancy: 4 to 6 years
Habitat: Native to slow-moving rivers and streams in western Colombia; typically found in shaded areas with dense vegetation and soft, acidic water
Tank Requirements
Minimum Tank Size: 15 gallons (57 liters) for a small group; 20+ gallons recommended for best behavior
Ideal Temperature: 73–81°F (23–27°C)
pH Range: 5.5–7.5
Water Hardness: Soft to moderately hard (3–10 dGH)
Temperament: Peaceful and calm; best kept in groups of 6 or more; males may display mild aggression during mating displays but are generally community-safe
Diet & Nutrition
Omnivorous: Yes — enjoys a varied diet of high-quality flakes or micro pellets, supplemented with small live or frozen foods such as brine shrimp, bloodworms, and daphnia. Occasional veggie-based foods (like spirulina flakes) are also beneficial.
