Serpae Tetra Fish Species Profile

Characteristics, Origin, and Helpful Information for Hobbyists

Serpae Tetra - Hyphessobrycon eques

Serpae tetras are popular flame-colored fish that move in bright red schools through your aquarium. They're quite popular in a community aquarium because of their beauty and ease of care, though they can become mildly aggressive when among slow-moving species. Add a school of six or more serpae tetras to your aquarium along with plants, rocks, and caves to keep them interested, and enjoy watching as they explore.

Species Overview

Common Names: Blood characin, callistus, callistus tetra, jewel tetra, red minor tetra, red serpae, serpa tetra, serpae tetra

Scientific Name: Hyphessobrycon eques

Adult Size: 1.75 inches (4.5 cm)

Life Expectancy: 5 years


Family Characidae
Origin Brazil and Paraguay
Social Peaceful schooling fish
Tank Level Mid dweller
Minimum Tank Size 20 gallons
Diet Omnivore, enjoys live foods
Breeding Egglayer


pH 5.0 to 7.8
Hardness 5 to 25 dGH
Temperature 72 to 79 F (22 to 26 C)

Origin and Distribution

Serpae tetras originate in the Amazon basin, inhabiting the Guaporé and Paraguay River basins in Argentina, Brazil, and upper Paraguay. Most specimens currently sold in the aquarium trade are captive bred rather than wild-caught; the species is not endangered. In the wild, this species prefers still and slow-moving backwaters such as lakes, ponds, and streams. They often congregate around tree roots and thick vegetation where they can find both safety and food.

This species is part of a group known as the blood tetras, referring to their red coloration. Considerable confusion and debate have continued over species within this group, as they have strong similarities. Serpaes are very similar to, but not identical with, Hyphessobrycon swegles, also called the red phantom tetra.

Colors and Markings

The deep red color of the serpae tetra adds to its popularity. The body of the serpae is flat and tall. A black comma-shaped spot is present just behind the gills. The dorsal fin, edged with white, is predominantly black, and all other fins are red. The anal fin is edged in black with a splash of white at the leading tip. These colors fade as the fish ages, particularly the spot behind the gills. Females are plumper and less brilliantly colored than their male counterparts. In captivity, long-finned variations have been produced.


The serpae tetra is generally considered a peaceful fish and should always be kept in schools of a half dozen or more. However, in smaller groups, they have been known to nip fins, an aggression that is most often directed at its own kind, especially during feeding times.

Ideal tankmates include other active fish of similar or larger size, such as barbs, danios, and larger tetras. Bottom-dwelling catfish and loaches are also suitable tankmates. Avoid keeping this species with fish that have long, flowing fins or that are slow-moving, such as angelfish or bettas. Also, avoid keeping them with smaller species of fish as they may get harassed. Serpae tetras are most likely to show aggression at feeding time; place food at several locations or use multiple feeding rings to help reduce nipping at feeding time.

Serpae Tetra Habitat and Care

The serpae tetra is most at home in an Amazon habitat. In nature, this fish is accustomed to quiet waters with roots and organic debris. Using peat or blackwater extract helps mimic this type of soft, acid water.

A dark-colored substrate is best, with somewhat subdued lighting. Leave an open swimming space with driftwood, plants, and décor around the edges to provide hiding places. Keep the water movement slow within the tank. Though serpae tetras are easy to care for, they are not recommended for a newly set-up tank, as they are sensitive to changes in water parameters.

Serpae Tetra Diet and Feeding

In their natural environment, serpae tetras eat small live foods such as insects, invertebrates, and worms. In the aquarium, they will accept virtually any food quite readily, including flake, pellet, freeze-dried, and frozen foods. To keep them in prime condition and bring out their colors, feed a good variety of food types, including live foods when available.

Gender Differences

Differences between the sexes are slight and most apparent when serpaes are ready to spawn. Males are more brightly colored and slimmer, and the dorsal fin is fully black. In females, the dorsal fin is paler. Females are also fuller in the body, even when not spawning.

Breeding the Serpae Tetra

Serpae tetras are relatively easy to breed as pairs or in groups of roughly an equal number of males and females. The key to successful breeding is to set up a tank with the proper habitat for spawning and subsequent grow-out of the fry.

Set up a small tank with dark-colored substrate, very dim lighting, and spawning mops or fine-leaved plants, such as java moss or Myriophyllum. The water should be very soft, no more than 6 to 8 dGH, and pH approximately 6.0. Provide gentle filtration, such as an air-driven sponge filter. Keep the water around 80 F (27 C).

Condition the spawning pair with a variety of foods, including live foods if possible. Males will become more colorful and females will become noticeably plump when ready to spawn. Eggs will be scattered over the plants or spawning mop. Once the eggs have been laid, remove the adults as they will consume the eggs. Turn off all lighting in the tank, since the eggs are highly sensitive to light.

In one to two days the eggs will hatch, after which they will feed on their yolk sack for several days. Once they are free swimming, they will feed on infusoria and freshly hatched brine shrimp. You can also provide finely crushed flake foods or commercially-prepared fry food in lieu of brine shrimp.

More Pet Fish Breeds and Further Research

If serpae tetras appeal to you, and you are interested in some compatible fish for your aquarium, read up on:

Check out additional fish breed profiles for more information on other freshwater fish.