Moenkhausia costae


Please note that the fish shown in the photo is not the exact fish you will receive and is only a representative of what a specimen will look like. The color may vary based on the age and sex (if listed as unsexed) of the fish you receive.

Minimum order: 6
SKU: Black Line Tail Tetra TR (M. costae) SM Categories: ,

This fish is covered by our Livestock Guarantee Policy


Moenkhausia costae, commonly known as the Black Line Tail Tetra or the Flag Tetra, is a beautiful species of freshwater fish found in South America. Here’s a summarized bullet point list of care tips for Moenkhausia costae:

Tank Requirements:
– Tank size: A minimum of 20 gallons is suitable for a small group (6-8).
– Filtration: Use a good quality filter to maintain water quality and provide gentle water flow.
– Water parameters: Temperature 72-82°F (22-28°C), pH 6.0-7.5, hardness 2-15 dGH.
– Substrate: Use fine gravel or sand to mimic their natural environment.

– Black Line Tailed Tetras are omnivores and have a varied diet in the wild.
– Offer a balanced diet that includes high-quality flakes, pellets, and supplement with live or frozen foods like brine shrimp, daphnia, and bloodworms.

– They are generally peaceful and can be kept with other small, non-aggressive fish.
– Avoid housing them with larger or aggressive species that may intimidate them.

Decor and Environment:
– Provide plenty of plants, floating vegetation, and open swimming spaces.
– Use driftwood and rocks to create natural hiding spots and simulate their natural habitat.
– Dim lighting can help reduce stress and enhance their colors.

Water Maintenance:
– Perform regular water changes (20-25% weekly) to maintain water quality and remove waste.
– Keep the water well-filtered and ensure good water circulation.

– Black Line Tail Tetras are shoaling fish, so keep them in groups of at least 6-8 individuals to reduce stress and encourage natural behavior.
– They are known for their striking striped patterns and graceful swimming.

– Monitor water parameters regularly using test kits to ensure optimal conditions.
– Quarantine new fish before introducing them to the main tank to prevent disease transmission.

– Breeding Black Line Tail Tetras in captivity is possible with proper care and conditions.
– Provide a separate breeding tank with soft, slightly acidic water and fine-leaved plants for potential spawning.
– Use marbles or a spawning mesh to protect the eggs from the adults.

Observation and Enjoyment:
– Spend time observing and enjoying the natural beauty and behavior of Black Line Tail Tetras.
– Create a peaceful and well-maintained environment to enhance their vibrant colors and showcase their active nature.

By following these care guidelines, you can provide a suitable and thriving aquarium for Moenkhausia costae, allowing them to display their best colors and behaviors and ensuring a healthy and enjoyable life in captivity.

Additional information