Serpae Tetra: Caring, Feeding and Breeding

Hyphessobrycon eques

Serpae Tetra
Faucon/Wikimedia Commons/CC BY-SA 2.5

Serpae Tetra: Overview

  • Scientific Name: Hyphessobrycon eques
  • Synonym: Cheirodon eques, Chirodon eques, Hemigrammus melasopterus, Hemigrammus serpae, Hyphessobrycon callistus, Hyphessobrycon serpae, Megalamphodus eques, Tetragonopterus callistus
  • Common Name: Blood Characin, Callistus, Callistus Tetra, Jewel Tetra, Red Minor Tetra, Red Serpae, Serpa Tetra, Serpae Tetra
  • Family: Characidae
  • Origin: Brazil and Paraguay
  • Adult Size: 1.75 inches (4.5 cm)
  • Social: Peaceful schooling fish
  • Lifespan: 5 years
  • Tank Level: Mid dweller
  • Minimum Tank Size: 20 gallons
  • Diet: Omnivore, enjoys live foods
  • Breeding: Egglayer
  • Care: Easy
  • pH: 5.0-7.8
  • Hardness: 5-25 dGH
  • Temperature: 72-79 F (22-26 C)


Serpae Tetras originate from 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.

This species is part of a group known as “Blood Tetras,” referring to their red coloration. Considerable confusion and debate have continued over species within this group, as they have strong similarities, and study of its taxonomic status continues.

Currently, this species is known by the scientific name Hyphessobrycon eques, but it has also been called: Cheirodon eques, Chirodon eques, Hemigrammus melasopterus, Hemigrammus serpae, Hyphessobrycon callistus, Hyphessobrycon serpae, Megalamphodus eques, and Tetragonopterus callistus.

Serpae Tetras are also known by the common names Blood Characin, Callistus, Callistus Tetra, Jewel Tetra, Red Minor Tetra, Red Serpae, and Serpa Tetra.


The deep red color of the Serpae Tetra adds to its popularity. The body of the Serpae is flat and tall, and it reaches an adult size of about one and three-quarters inch.

A black comma-shaped spot is present just behind the gills. The dorsal fin is predominantly black, edged with white, 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.

Serpae Tetras are generally peaceful when kept in a school. However, they have been known to nip fins, a behavior that is most often directed at its own kind, especially during feeding times. Females are plumper and less brilliantly colored than their male counterparts. 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. 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 harass them. 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.


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 will help mimic this type of soft, acid water.

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


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.

Sexual Differences

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


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 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 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.