The Blackline Tetra (Moenkhausia costae), also known as the Costae tetra, is a popular freshwater schooling fish native to South America. Recognized by the striking black line along its silver body and active swimming behavior, it adds energy and color to community aquariums. Hardy and adaptable, they thrive in groups of five or more and are known to jump, so a covered tank is recommended. Males are smaller and more colorful, while females tend to be rounder and larger.
Scientific Name
Moenkhausia costae
Habitat
Freshwater rivers and streams with dense aquatic vegetation (exact origin not well documented)
Conservation
Not endangered; commonly found in aquarium trade
Lifespan
3–5 years in captivity
Fun Fact
They are fast swimmers and may leap out of the tank, so keeping a lid is essential!
Diet
Omnivorous; eats flakes, pellets, granules, and benefits from live foods like blackworms, bloodworms, and daphnia
Average Size
Up to 5 cm (2 inches)
Location / Placement info
Displayed in the Coastal Reef Exhibit, near the Ocean-View Tunnel
FAQ
Are blackline tetras good for beginners?
Yes, they are hardy, peaceful, and easy to care for.
How many blackline tetras should be kept together?
At least 5 to form a healthy shoal.
Do blackline tetra jump out of tanks?
Yes, they are known jumpers; a covered tank is essential.
What is blackline tetra ideal tank setup?
A planted tank with open swimming space and moderate flow.
Are Blackline Tetra aggressive?
No, they are peaceful and do well in community aquariums.
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