Ruby Tetra (Axelrodia riesei)
The Ruby Tetra is a beautiful nano freshwater fish prized for its vibrant ruby-red to orange coloration and peaceful schooling behavior. Also known as the Ruby Red Tetra, this tiny species develops its best coloration when comfortable and maintained under subdued lighting. When kept in a healthy group against a background of lush green plants, Ruby Tetras create an impressive splash of warm color in smaller freshwater aquariums.
Native to the upper Meta River basin in Colombia, Axelrodia riesei naturally inhabits soft, acidic waters with abundant vegetation, submerged wood, and organic material. In the aquarium, it thrives in mature setups with live plants, driftwood, leaf litter, gentle filtration, and areas of subdued lighting. Floating plants can also help create the shaded conditions this species prefers.
Ruby Tetras are highly social and should be kept in groups of at least six, although a school of 10 or more is preferred. Larger groups help the fish feel secure, encourage more natural schooling behavior, and create a much more impressive visual display.
These tiny tetras are omnivorous micropredators and require appropriately sized foods. High-quality micro pellets and finely crushed flakes can be supplemented with baby brine shrimp, daphnia, Cyclops, and other tiny frozen or live foods. A varied diet helps promote strong coloration and healthy body condition.
Ruby Tetras are exceptionally peaceful and make excellent companions for other small community species such as Green Neon Tetras, Ember Tetras, Chili Rasboras, Pencilfish, Pygmy Corydoras, Otocinclus, and peaceful dwarf cichlids. Because of their tiny adult size, larger or aggressive tank mates should be avoided.
Scientific Name: Axelrodia riesei
Common Name: Ruby Tetra, Ruby Red Tetra
Care Level: Easy to Moderate
Temperament: Peaceful
Diet: Omnivore / Micropredator
Adult Size: Approximately 0.8–1 Inch
Minimum Tank Size: 10 Gallons
Recommended Group Size: 6 or More (10+ Preferred)
Origin: Colombia, South America
If you're looking for a tiny schooling fish with beautiful red coloration, the Ruby Tetra is an outstanding choice. Its peaceful temperament, compact size, and brilliant ruby tones make it a spectacular addition to planted nano aquariums and peaceful freshwater communities.
