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Black Skirt Tetra (Gymnocorymbus ternetzi)

Welcome to our detailed exploration of the Black Skirt Tetra, a popular and captivating freshwater fish that adds beauty and vibrancy to any aquarium. In this detailed guide, we will take a look at various aspects of the Black Skirt Tetra, offering insights for both novice and experienced fish enthusiasts.

Black Skirt Tetra Facts

Scientific Name Gymnocorymbus ternetzi
Common Names Black Skirt Tetra, Black Widow Tetra, Petticoat Tetra, Black Tetra, Black Fin Tetra
Origin South American Rivers
Average Size 2 – 3 inches (5 – 7.5 cm)
Lifespan 3-5 years
Water Temperature 70 – 79°F (21-26°C)
pH Range 6.0 – 7.5
Temperament Peaceful, Social
Diet Omnivorous
Aquarium Size Minimum 20 gallons
Compatibility Good for community tanks with similar sized and peaceful fish

Black Skirt Tetra Profile

The Black Skirt Tetra, scientifically known as Gymnocorymbus ternetzi, is a small, peaceful fish native to South America’s river basins. It’s known for its distinctive black, vertically striped pattern and flowing finnage. These tetras typically grow up to 2-3 inches in length and have a lifespan of approximately 3-5 years in well-maintained aquarium conditions.

Black Widow Tetra Coloring

One of the most striking features of the Black Widow Tetra is its coloration. The body is primarily a translucent silver-gray, adorned with prominent black vertical stripes. The fins are usually black or dark gray, and in some cases, may have a delicate, white edging.

Black Skirt Tetra Habitat

The Black Skirt Tetra naturally inhabits the calm, warm waters of South America’s river basins, predominantly in Brazil and Paraguay. These environments are characterized by soft, slightly acidic water, abundant vegetation, and a diverse ecosystem, providing these fish with ample hiding spots and a rich source of food, creating an ideal setting for their schooling behavior.

Black Skirt Tetra Aquarium Setup

Setting up the perfect aquarium for Black Skirt Tetras is not just about aesthetics; it’s about creating an environment that closely mimics their natural habitat. This setup ensures their health, happiness, and longevity.

  • Tank Size and Water Parameters

A minimum of a 20-gallon tank is recommended for Black Skirt Tetras, especially if you plan on keeping a small school. These active swimmers need space to roam. The ideal water temperature for these tetras is between 70-79°F (21-26°C), with a pH range of 6.0-7.5, and water hardness between 5-19 dGH. It’s essential to regularly check the water parameters to maintain a stable environment.

  • Filtration and Water Movement

A good filtration system is critical to keep the water clean and oxygen-rich. However, Black Skirt Tetras prefer a gentle water flow. Therefore, choose a filter that provides efficient filtration without creating too much turbulence in the water. Sponge filters or hang-on-back filters with adjustable flow rates are excellent choices.

  • Lighting and Substrate

Lighting should be moderate to mimic their natural, somewhat dimly-lit habitat. Subdued lighting also helps to showcase their unique coloring. For the substrate, opt for dark gravel or sand. This not only creates a natural-looking environment but also helps in accentuating the colors of the Black Skirt Tetras.

  • Plants and Decorations

High Fin Black Skirt Tetras thrive in a planted aquarium. Live plants such as Java Fern, Anubias, and Amazon Sword provide hiding spots and mimic their natural habitat. You can also add driftwood and caves for additional shelter. Make sure there is still ample open space for swimming.

  • Maintaining the Aquarium

Regular maintenance is key to a healthy aquarium. This includes weekly water changes of about 25%, checking filter operation, and monitoring water parameters. Also, be vigilant about removing any uneaten food or debris to prevent ammonia spikes.

Black Skirt Tetra Breeding

The breeding of Black Skirt Tetras, while not overly complicated, requires specific conditions to be successful. Understanding and replicating their natural breeding environment is key to encouraging them to spawn.

Breeding Environment

To begin, set up a separate breeding tank. This tank should be about 10-20 gallons in size and have a sponge filter to keep water conditions optimal without posing a risk to fry. The water temperature should be slightly warmer than in the main tank, ideally around 78-80°F (25-27°C). Soft, slightly acidic water with a pH of about 6.5 is ideal. Dim lighting and the presence of fine-leaved plants or a spawning mop will simulate the natural breeding grounds of black fin tetras and provide a place for the fish to deposit their eggs.

Spawning Process

Introduce a well-conditioned pair or a small group of males and females into the breeding tank. Conditioning them with a diet rich in live foods can help trigger spawning. The spawning process usually occurs early in the morning. Black Skirt Tetras are egg scatterers, meaning they will release and fertilize the eggs as they swim, often among the plants or on the tank’s bottom.

After spawning, it is crucial to remove the adult fish from the breeding tank to prevent them from eating the eggs. The eggs will hatch in about 24-36 hours, depending on the temperature. Initially, the fry will feed on their yolk sacs, but after about 48 hours, they will require food. Infusoria, newly hatched brine shrimp, or commercial fry food are suitable for the young fry.

Proper care during this early stage is vital for the survival of the fry. Regular water changes, careful feeding, and maintaining stable water conditions will help ensure a high survival rate among the newborn black widow tetras.

Black Tetra Diet & Feeding

Black Fin Tetras are omnivores and not particularly fussy eaters. A balanced diet for these fish should include high-quality flake food, supplemented with live or frozen foods such as brine shrimp, daphnia, and bloodworms. Regular feeding of small amounts 2-3 times a day is optimal for their health.

Black Skirt Tetra Compatibility

These tetras are generally peaceful and suitable for community tanks. They do best with similarly sized and temperament fish. Ideal tankmates include Rasboras, Danios, Mollies, Platies, Honey Gourami, Kuhli Loaches, Dward Gourami, Neon Tetra, and Corydoras Catfish. Avoid housing them with large or aggressive species. Keeping them in groups of at least five will help maintain a harmonious environment, as they are naturally schooling fish.

Black Fin Tetra Common Diseases

Black Skirt Tetras are generally hardy, but they can be susceptible to common freshwater fish diseases like Ich (white spot disease), fin rot, and fungal infections. Good tank maintenance, proper diet, and regular water quality checks are crucial to prevent these ailments and ensure the health of these charming fish.


The High Fin Black Skirt Tetra is a delightful addition to any freshwater aquarium. With their unique appearance and peaceful nature, they bring a dynamic yet serene presence. Proper care, a well-set-up aquarium, and a balanced diet will ensure these charming fish thrive, providing enjoyment for years to come.