Meet the Calypso Tetra (Hyphessobrycon axelrodi), an exquisite and rare dwarf nano fish that brings subtle elegance and lively activity to the freshwater aquarium. Known for its mesmerizing iridescence and distinct white-tipped fins, this peaceful schooling characin is a prize addition for dedicated hobbyists and nano tank enthusiasts alike.

Product Overview & Care Guide

Environment & Tank Setup

To mimic their natural habitat, design a well-planted aquarium with a dark sandy or fine-gravel substrate, which helps their silver iridescence pop. Incorporate floating plants like Salvinia or Amazon Frogbit to create shaded areas, giving these peaceful fish a sense of security. Adding driftwood and leaf litter can introduce beneficial tannins that replicate their native wild streams.

Tank Size

Due to their diminutive dwarf size—reaching a maximum length of only 0.8 to 1.2 inches (2 to 3 cm)—a minimum tank size of 10 gallons is highly recommended for a small school.

Care & Water Parameters

Calypso Tetras are relatively hardy when introduced to a mature, biologically stable ecosystem. They appreciate steady water parameters and clean, well-oxygenated water with gentle filtration.

• Temperature: 75°F to 82°F (24°C to 28°C)

• pH Level: 6.0 to 7.5

• Water Hardness: Soft to moderately hard (5 to 15 dGH)

Feeding & Diet

As natural omnivores, these nano tetras have small mouths and require appropriately sized foods. Offer a high-quality base of micro-pellets or crushed flakes. Supplement their diet with live or frozen foods such as baby brine shrimp, daphnia, and cyclops to enhance their coloration and vitality.

Tank Mates & Temperament

The Calypso Tetra is an exceptionally peaceful community fish. Because of their defensive schooling instincts, they must be kept in groups of at least 6 to 8 individuals (ideally 10 or more). In larger schools, they display tighter swimming patterns and far greater confidence. Excellent tank mates include other peaceful nano fish such as Rasboras, Pygmy Corydoras, small Loricariids, and freshwater dwarf shrimp. Avoid keeping them with large, aggressive, or predatory species that could easily view them as a snack.

Breeding

Breeding Hyphessobrycon axelrodi follows a typical egg-scattering pattern. To successfully breed them, set up a dedicated, dimly lit breeding tank filled with fine-leaved plants like Java Moss or spawning mops. Condition the parents with premium live foods. Females are slightly larger and rounder when carrying eggs, while males exhibit more intense silver coloration. Parents should be removed immediately after spawning to protect the eggs, which will hatch in about 24 to 36 hours.

PLEASE READ BEFORE ORDERING

• The photos shown on fish product pages are representations of adult fish and are NOT the actual fish that you will be receiving. 
• Please visit our “Ordering/Shipping fish” page prior to checking out to familiarize yourself with our process.
• We ship fish exclusively using overnight shipping with either FedEx or UPS. We will not ship fish with lesser expensive shipping services like “Ground” or “Priority Mail”. This is to ensure the safety of the fish. 
• Unless specified, all fish are sold as unsexed.