Serpae Tetra
Hyphessobrycon eques
Also known as: Red minor tetra, Blood tetra, Callistus tetra
Quick Facts
- Adult size: 3.5-4.5 cm (1.4-1.75 inches)
- Minimum tank size: 75 litres (20 gallons)
- Lifespan: 5–7 years
- Temperament: semi-aggressive
- Swimming level: middle
- Diet: omnivore
- Minimum group size: 8
- Difficulty: intermediate
Water Parameters
- Temperature: 22–27°C
- pH: 5.5–7.5
- Hardness (GH): 36–214 ppm (2–12 dGH)
Values above are general hardness (GH). For carbonate hardness (KH), the buffer that keeps pH stable, see the water parameters guide.
Care Summary
A deep-bodied, blood-red tetra with a black shoulder mark and a deserved reputation as one of the community tank's most persistent fin-nippers. Sold everywhere and easy to keep, serpae tetras are frequently bought as peaceful schoolers and then quietly shred the fins of every slow tankmate, which is why they earn a caution rather than a simple recommendation. Kept correctly, in a school of eight or more with fast, sturdy companions, they are hardy, long-lived, and genuinely beautiful, flashing deep red as the group turns. The honest verdict mirrors the tiger barb: an excellent fish for the right, robust setup, and a steady source of damaged fins in the wrong one. Avoid the dyed and 'painted' variants, which are short-lived and produced by an unpleasant process.
Tankmates
Hardy, inexpensive, and genuinely striking in a school, but a committed fin-nipper, more so than the black skirt and on a par with the tiger barb. The behaviour eases in a large group of eight or more, where the fish establish a pecking order among themselves and harass each other rather than their tankmates; in small groups they are relentless. Keep them well away from slow or long-finned fish: bettas, fancy guppies, angelfish, gouramis, and the flowing-finned congo tetra are all targets. The right companions are fast, robust, and short-finned: danios, other barbs, the black skirt tetra, and armoured catfish. A planted tank with broken sightlines also helps spread out the nipping.
Compatible with
Avoid keeping with
- Betta
- Guppy
- Angelfish
- Dwarf Gourami
- Pearl Gourami
- Congo Tetra
- Long Finned Species
Common Problems
- fin nipping of slow or long-finned tankmates
- increased aggression in groups smaller than 8
- ich
- short lifespan in dyed or 'painted' variants
Sources: seriouslyfish.com, fishbase.org · Last updated: 2026-06-20