Black Tetra: Fish Species Profile

Species Overview

The Black Tetra (Gymnocorymbus ternetzi), also known as the Black Skirt Tetra or Black Widow Tetra, is a popular freshwater fish admired for its distinctive appearance and hardy nature. Originating from South America, this species is a favorite among aquarists seeking an active and visually appealing addition to their community tanks.

• Common Names: Black Tetra, Black Skirt Tetra, Black Widow Tetra
• Scientific Name: Gymnocorymbus ternetzi
• Adult Size: Up to 2.5 inches (6.5 cm)
• Life Expectancy: 3–5 years

Characteristics

• Family: Characidae
• Origin: Paraguay River basin, South America
• Social: Peaceful schooling fish
• Tank Level: Mid to upper water levels
• Minimum Tank Size: 20 gallons
• Diet: Omnivore
• Breeding: Egg layer
• Care Level: Easy
• pH: 6.0–7.5
• Hardness: 4–8 dKH
• Temperature: 70–85°F (21–29°C)

Origin and Distribution

Black Tetras are native to the Paraguay River basin in South America, encompassing regions of Brazil, Paraguay, and Argentina. They inhabit slow-moving rivers and streams with dense vegetation, providing ample hiding spots and feeding opportunities.

Colors and Markings

This species features a laterally compressed, silver-gray body with two prominent vertical black bars behind the gills. The dorsal and anal fins are broad and dark, giving the appearance of a “skirt,” hence the common name Black Skirt Tetra. Juveniles display more intense coloration, which may fade slightly as they mature.

Tankmates

Black Tetras are generally peaceful and thrive in community tanks with other non-aggressive species. Suitable tankmates include:

• Other Tetra species
• Rasboras
• Corydoras Catfish
• Gouramis
• Livebearers like Guppies and Mollies

It’s advisable to keep them in groups of at least six to minimize fin-nipping behavior and promote natural schooling activities.

Habitat and Care

To replicate their natural environment:

• Tank Size: A minimum of 20 gallons is recommended to accommodate a small school and provide ample swimming space.
• Substrate: Use a dark substrate to enhance their coloration.
• Plants: Incorporate live plants such as Java Fern, Anubias, and floating species to provide cover and mimic their natural habitat.
• Lighting: Moderate lighting is ideal to showcase their features without causing stress.
• Filtration: Ensure efficient filtration to maintain water quality, as they are sensitive to poor conditions.

Regular water changes and monitoring of parameters are essential to keep them healthy.

Diet and Feeding

Black Tetras are omnivorous and thrive on a varied diet. Offer them:

• High-quality flake or pellet food
• Live or frozen foods like bloodworms, brine shrimp, and daphnia
• Occasional vegetable matter such as blanched spinach or spirulina-based flakes

Feed them small amounts 2–3 times daily, ensuring they consume all the food within a few minutes.

Gender Differences

Males are typically more slender with a slightly more pronounced dorsal fin, while females are rounder, especially when carrying eggs. The differences are subtle and may require close observation to distinguish.

Breeding

Breeding Black Tetras in captivity is relatively straightforward:

• Breeding Tank: Set up a separate tank with soft, slightly acidic water and fine-leaved plants or spawning mops.
• Conditioning: Feed breeding pairs a high-protein diet of live and frozen foods to encourage spawning.
• Spawning: After spawning, remove adults to prevent them from eating the eggs.

Eggs typically hatch within 24–36 hours, and fry become free-swimming a few days later. Feed fry infusoria or commercially available fry food until they are large enough to accept baby brine shrimp.

Further Research

For more information on similar species and care techniques, consider exploring:

• Serpae Tetra
• Buenos Aires Tetra
• Rosy Barb

FAQ

How many Black Tetras should I keep together?
It’s best to keep them in groups of at least six individuals to reduce stress and encourage natural schooling behavior.

Are Black Tetras suitable for beginners?
Yes, their hardy nature and peaceful temperament make them suitable for novice aquarists.

What is the ideal tank setup for Black Tetras?
A well-planted tank with ample swimming space, moderate lighting, and stable water parameters closely mimics their natural habitat and helps them thrive.

This profile provides essential information for successfully keeping and enjoying Black Tetras in your aquarium.