Hyphessobrycon callistus (Blood Tetra Extra Red)

Overview

The Blood Tetra Extra Red, scientifically known as Hyphessobrycon callistus (often considered synonymous with Hyphessobrycon eques and commonly called the Serpae Tetra), is an incredibly popular freshwater aquarium fish. The "Extra Red" variant has been selectively bred or sourced to showcase a much deeper, more vibrant crimson hue than the standard wild type. Known for their hardiness and dynamic schooling behaviors, they bring a vivid splash of color and constant motion to the mid-levels of the aquarium.

Distribution and Habitat

In the wild, this species is widely distributed throughout the Amazon River basin, as well as the Guaporé and Paraguay River basins in South America. They naturally inhabit slow-moving tributaries, ponds, and small lakes featuring dense vegetation. The waters they originate from are typically stained dark with tannins from decaying organic matter, creating a soft, slightly acidic environment shaded by the dense jungle canopy above.

Description of Blood Tetra Extra Red

Body shape:

This tetra possesses a classic tall, laterally compressed, and somewhat oval-shaped body, which allows it to maneuver swiftly through heavily planted environments.

Color:

The hallmark of the "Extra Red" variant is its intense, deep crimson to blood-red base coloration. A distinct, dark, comma-shaped spot is prominently displayed just behind the gills on the flanks.

Barbels:

Like other characins, the Blood Tetra Extra Red does not possess any barbels.

Snout:

The snout is short, blunt, and slightly rounded, featuring a terminal mouth well-adapted to snatching food from the water column.

Eyes:

The eyes are relatively large, featuring a dark central pupil surrounded by a reflective, reddish-silver iris that blends well with its body coloration.

Fins:

The dorsal fin is tall and predominantly black, strikingly tipped with white. The anal fin sweeps along the bottom of the body, colored bright red with a distinct black margin. Pelvic and pectoral fins are generally a translucent red.

The Tail:

The caudal (tail) fin is deeply forked and mostly translucent red, lacking the black and white markings seen on the dorsal and anal fins.

Temper

While generally considered a community fish, the Blood Tetra Extra Red has a semi-aggressive streak. They are notorious fin-nippers, particularly when kept in inadequate numbers or housed with slow-moving, long-finned tank mates like Angelfish or Bettas.

Sociality

They are highly social, obligate schooling fish. To mitigate their fin-nipping tendencies and keep them stress-free, they must be kept in groups of at least 6 to 8 individuals. In a proper school, they will direct their chasing and sparring behaviors toward one another rather than bothering other species.

Activity

These tetras are extremely active mid-water dwellers. They spend the majority of their day darting around the tank, playfully chasing each other, and exploring their environment. Their constant motion makes them a highly entertaining species to observe.

Keeping and Caring for Blood Tetra Extra Red

Tank size:

A minimum tank size of 20 gallons (approximately 75 liters) is recommended. Although they are small fish, their high activity levels and need to be kept in schools require ample swimming space.

Water Parameters:

Temperature

They thrive in warm tropical waters, with an ideal temperature range of 22-26°C (72-79°F).

pH

They prefer slightly acidic to neutral water conditions, with a pH range between 5.0 and 7.5 being optimal.

Hardness

Soft to moderately hard water is best, ideally kept between 5 and 15 dGH.

Ammonia, Nitrite, Nitrate

As with all aquarium fish, Ammonia and Nitrite must always be at 0 ppm. Nitrates should be maintained below 20 ppm through regular water changes and adequate filtration.

Lighting

Moderate to dim lighting is preferred. Bright lights can wash out their spectacular red coloration and make them skittish. Floating plants can be used to diffuse harsh lighting.

Water flow

A gentle to moderate water flow is ideal, mimicking the sluggish tributaries of their natural habitat without exhausting them.

Decorations and Plants

A heavily planted aquarium with dark substrate will make their red colors pop beautifully. Provide plenty of dense background and midground vegetation, but leave open swimming space in the center. Driftwood, leaf litter, and botanical additions that release tannins are highly recommended to simulate their native blackwater environments.

Diet

The Blood Tetra Extra Red is an omnivore and is not a picky eater. In the aquarium, they will readily accept high-quality flake foods, micro-pellets, and freeze-dried foods. To ensure optimal health and the brightest coloration, supplement their dry diet with live or frozen foods such as daphnia, bloodworms, and brine shrimp.

Some Feeding Tips

Feed them small amounts once or twice a day, only providing what they can consume within a couple of minutes. Utilizing color-enhancing foods rich in astaxanthin or spirulina will help maintain their deep "extra red" appearance.

Breeding

Breeding the Blood Tetra is relatively straightforward as they are egg-scatterers. To breed them, set up a separate, dimly lit breeding tank with soft, acidic water and fine-leaved plants like Java Moss or spawning mops. Condition the adults with plenty of live foods. Spawning usually occurs in the early morning, where the female scatters eggs among the plants and the male fertilizes them. Because they exhibit no parental care and will actively eat their own eggs, the adult fish must be removed immediately after spawning. The eggs will hatch in about 24 to 36 hours, and the fry can be fed infusoria until they are large enough to accept baby brine shrimp.

Conclusion

The Blood Tetra Extra Red is a captivating, energetic species that brings a fiery burst of color to the home aquarium. While their fin-nipping tendencies require some careful planning when choosing tank mates, keeping them in a properly sized school within a well-planted tank easily mitigates this issue. For aquarists looking for a hardy, active, and visually stunning tetra, this extra red variant is an outstanding choice.