Black skirt tetra - Gymnocorymbus ternetzi

Scientific name: Gymnocorymbus ternetzi

Common name: Black skirt tetra

Family: Characidae

Usual size in fish tanks: 3 - 4 cm (1.18 - 1.57 inch)

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Recommended pH range for the species: 5.9 - 8.3

Recommended water hardness (dGH): 4 - 18°N (71.43 - 321.43ppm)

0°C 32°F30°C 86°F

Recommended temperature: 20 - 26 °C (68 - 78.8°F)

The way how these fish reproduce: Spawning

Where the species comes from: South America

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

Origins

The Black Skirt Tetra (Gymnocorymbus ternetzi) originates from the river basins of South America, particularly in Bolivia, Brazil, and parts of Argentina. These regions are known for their cooler waters compared to tropical areas, making this tetra well-suited to slightly lower temperatures. In their natural habitat, Black Skirt Tetras thrive in slow-moving rivers and streams with dense vegetation and soft substrates. For aquarium setups, maintaining a water temperature of 20-26°C (68-78.8°F) is ideal. When choosing tankmates, ensure they also prefer similar cooler temperature ranges to create a harmonious environment.

General Care Information

The Black Skirt Tetra is a hardy and peaceful schooling fish, best kept in groups of at least 6 individuals. In smaller groups, they may become shy and stressed. Despite their peaceful nature, they have a tendency to nip at the fins of slower-moving or long-finned species, such as Angelfish. Avoid housing them with such species to prevent stress or injuries.

These tetras thrive in well-planted tanks with subdued lighting, which helps replicate their natural habitat and makes them feel secure. Floating plants or adjustable lights can help diffuse bright lighting. Use a dark substrate and decorations like driftwood or rocks to create hiding spots and enhance their colors. Regular water changes and good filtration are essential for maintaining water quality and overall health.

Feeding

Black Skirt Tetras are omnivorous and readily accept a variety of foods. A balanced diet consisting of high-quality flakes or small pellets should serve as their staple. Supplement this with occasional protein-rich treats like bloodworms, brine shrimp, and daphnia to enhance their health and coloration. Additionally, consider adding vegetable matter such as spirulina-based foods to ensure a varied diet. Feed small portions twice daily and remove uneaten food to maintain water quality.

Sexing

Sexing Black Skirt Tetras is relatively straightforward. Females tend to have a fuller, plumper body, particularly when carrying eggs, while males are slimmer and often exhibit slightly elongated fins. Observing these traits can help distinguish between the sexes in a group.

Breeding

Breeding Black Skirt Tetras can be challenging but is achievable with the right setup. These fish are egg scatterers, and breeding success is more likely in a dedicated breeding tank with soft, slightly alkaline water. Include fine-leaved plants or spawning mops, as these provide ideal sites for egg-laying. Glass marbles or a mesh layer on the substrate can help protect the eggs from being eaten by adult fish.

During courtship, males display vibrant coloration to attract females. Spawning typically occurs in the early morning, and once the eggs are laid, remove the adults to prevent them from consuming the eggs. The eggs will hatch in about 24-36 hours, and the fry will become free-swimming within 3-5 days. Feed the fry with Artemia salina (newly hatched brine shrimp) or finely crushed flake food once their yolk sacs are absorbed.

Lifespan

With proper care, Black Skirt Tetras can live for 3 to 6 years, and potentially longer in optimal conditions. Maintaining stable water parameters, a balanced diet, and a stress-free environment is key to their longevity.

Questions and Answers

This question was added here due to the merging of aqua-fish.net/answers with related pages on March 25, 2011:

Why does my Black Skirt Tetra lose its black color?

Answer: This is a common occurrence as the fish ages. The vibrant black coloration gradually fades to grey as part of their natural aging process.

Short Description

The Black Skirt Tetra (Gymnocorymbus ternetzi) is a peaceful and hardy fish native to South America. Known for its distinctive black coloration and flowing fins, this species thrives in cooler, well-planted aquariums. Best kept in groups, they are active swimmers that prefer subdued lighting and a secure environment. While ideal for community tanks, care should be taken to avoid housing them with long-finned species due to their fin-nipping tendencies. With proper care, these tetras add beauty and activity to any aquarium.