Black Widow Tetra – Detailed Product Description

• Overview & Appearance
  The Black Widow Tetra (Gymnocorymbus ternetzi), also known as the Black Skirt Tetra, is a classic and popular freshwater aquarium fish recognized for its distinctive black dorsal and anal fins that resemble a flowing skirt. Its body is typically silver to gray with two vertical black bands near the head, gradually fading as the fish matures. The contrast between its dark fins and lighter body gives it a bold, elegant appearance. As they age, the black coloration may become less intense, but their graceful shape and active swimming behavior remain appealing.

• Tank Size & Setup
  Black Widow Tetras are schooling fish and should be kept in groups of at least 6 or more to reduce stress and minimize fin-nipping behavior. A minimum tank size of 15–20 gallons is recommended, with larger tanks preferred for bigger schools.
  Ideal tank setup includes:

  • Planted aquarium with live plants like Java fern, Anubias, or Vallisneria

  • Open swimming space in the middle of the tank

  • Driftwood or decorations for shelter

  • Moderate lighting (not too bright)

A well-balanced aquascape with both hiding spots and open areas will keep them comfortable and active.

• Water Conditions
  Black Widow Tetras are hardy and adaptable, making them suitable for beginners:

  • Temperature: 22°C – 28°C (72°F – 82°F)

  • pH Level: 6.0 – 7.5 (slightly acidic to neutral)

  • Water Hardness: 5 – 15 dGH (moderate hardness)

  • Filtration: Moderate flow; they adapt well to most standard filtration systems

  • Water Changes: Weekly 20–30% water changes are recommended

They tolerate a range of conditions but thrive best in stable, clean water.

• Behavior & Temperament
  Black Widow Tetras are semi-peaceful fish with a slightly nippy tendency, especially if kept in small groups. In proper schools, aggression is usually reduced and spread out, making them more suitable for community tanks. They are active swimmers and typically occupy the mid-water level. Their playful, energetic nature adds constant movement to the aquarium.

• Tank Mates
  Choose tank mates carefully due to their occasional fin-nipping behavior:

  • Suitable tank mates:

    • Other medium-sized tetras

    • Rasboras

    • Danios

    • Corydoras catfish

    • Larger peaceful fish

  • Avoid:

    • Long-finned fish (bettas, angelfish, guppies with large fins)

    • Very small or timid species

    • Aggressive or territorial fish

A well-planned community helps maintain harmony in the tank.

• Feeding Habits
  Black Widow Tetras are omnivores and easy to feed:

  • Staple Diet: High-quality flakes or pellets

  • Protein Foods: Bloodworms, brine shrimp, daphnia (live or frozen)

  • Supplemental Foods: Occasional plant-based flakes

Feed 1–2 times daily in small amounts. They have a strong appetite, so avoid overfeeding to maintain water quality.

• Care & Maintenance
  These fish are low-maintenance and ideal for beginner aquarists. Key care tips:

  • Keep them in proper groups to reduce aggression

  • Maintain consistent water parameters

  • Provide a balanced diet

  • Perform regular tank cleaning and water changes

They are generally hardy but can develop common diseases like ich if stressed or kept in poor water conditions.

• Breeding Information
  Black Widow Tetras are egg scatterers and can be bred in captivity. A separate breeding tank with soft, slightly acidic water and dim lighting is recommended. Provide fine-leaved plants or spawning mops. After spawning, remove the adults to prevent them from eating the eggs. Eggs hatch within about 24–36 hours, and fry require infusoria before progressing to baby brine shrimp.

• Why Choose Black Widow Tetra?
  The Black Widow Tetra is a reliable and attractive choice for any freshwater aquarium. Its bold coloration, active schooling behavior, and hardy nature make it perfect for beginners and experienced aquarists alike. Whether in a community tank or a species-only setup, this fish brings both contrast and energy, enhancing the overall beauty and balance of your aquarium.