Serpae Tetra

Hyphessobrycon eques

Characins

A striking, deep-red schooling fish known for its highly active nature. While hardy and beautiful, Serpae Tetras are notorious fin-nippers. This behavior is usually localized within their own pecking order if kept in large enough schools (8+), but they should never be housed with slow-moving or long-finned tank mates like Bettas, Angelfish, or Gouramis.

At a Glance

Adult Size4.5 cm
Body ShapeCompressed
Growth RateModerate
TemperamentSemi-Aggressive
Water TypeFreshwater Only
Flow PreferenceModerate
Waste OutputLow
StockingSchool of 6+

Tank Requirements

Minimum Volume75 L
Minimum Length60 cm
FlowModerate
Water TypeFreshwater Only
Must-Haves in the Tank
Plants - Densely covered

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Water Parameters

Temperature2228°C
pH57.5
Hardness215 dGH

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Temperament & Compatibility

Aggression LevelSemi-Aggressive
5/10
Where They Swim
Surface
Mid-level
Bottom
Stocking Guidelines
Keep at Least6 fish
Max per TankNo limit
Can Live Alone?No — needs a group
Behavior Traits
Fin NipperHyperactive / Fast SwimmerFry PredatorAggressive to same species/look-alikes

Available Varieties

Each variety inherits the species defaults above. Only differences are highlighted.

Standard

Same care requirements as the base species

Also known as: Short Finned, Wild Type

Long Finned

Differs in 2 traits from base species

Also known as: Longfin Serpae, Veiltail Serpae

FlowLow
Behavior Traits
Long Finned (Nipper Target)Fin NipperHyperactive / Fast SwimmerFry PredatorAggressive to same species/look-alikes

Serpae Tetra Care Guide Summary

The Serpae Tetra, scientifically known as Hyphessobrycon eques, belongs to the Characins family group. Adults reach a maximum size of approximately 4.5 cm and have a compressed body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the mid-level and bottom zones of the aquarium and produces a low level of biological waste.

To thrive, the Serpae Tetra requires a freshwater only aquarium with a minimum volume of 75 litres and a tank length of at least 60 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 57.5 and a general hardness of 215 dGH. A moderate water flow is preferred. An aquarium test kit can help you monitor these values.

The Serpae Tetra is a rewarding species to keep, provided its core environmental needs are met. This species is available in 2 varieties: Standard and Long Finned. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.

Serpae Tetra Habitat Setup

When setting up an aquarium for the Serpae Tetra, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level and bottom zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include dense planting to provide cover, break sightlines, and reduce stress.

Serpae Tetra Compatibility Notes

Classified as semi-aggressive, the Serpae Tetra is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, avoid housing with slow-moving or long-finned species that may become targets for fin nipping, conspecific aggression can be intense, especially in smaller tanks, and their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the mid-level and bottom zones can help reduce competition and territorial overlap.

Frequently Asked Questions About Serpae Tetra

How big does Serpae Tetra get?+
Serpae Tetra (Hyphessobrycon eques) typically reaches a maximum adult size of approximately 4.5 cm. They have a compressed body shape and a moderate growth rate.
What tank size does Serpae Tetra need?+
A minimum aquarium volume of 75 litres and a tank length of at least 60 cm are recommended for Serpae Tetra. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Serpae Tetra need?+
Serpae Tetra thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 5 and 7.5, and a general hardness of 2–15 dGH. A moderate water flow is preferred.
Is Serpae Tetra peaceful or aggressive?+
Serpae Tetra is classified as semi-aggressive with an aggression score of 5 out of 10. They can work in community setups but may clash with certain tankmates.
How many Serpae Tetra should be kept together?+
Serpae Tetra is a schooling species and should be kept in groups of at least 6. Larger groups help distribute aggression and encourage natural schooling behaviour.
Does Serpae Tetra have any special tank requirements?+
Yes. Serpae Tetra benefits from plants - densely covered in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.

Similar Species

Lemon Tetra

Hyphessobrycon pulchripinnis

Characins
5 cm Peaceful

A peaceful, deep-bodied schooling tetra known for its translucent yellow coloration and striking black and yellow fins. They are robust and active, making them an excellent choice for planted community aquariums. Their colors intensify significantly in a well-established tank with a dark substrate and proper schooling numbers.

Black Skirt Tetra

Gymnocorymbus ternetzi

Characins
7 cm Mostly Peaceful

A very hardy, deep-bodied schooling tetra native to South America. They are incredibly popular for beginners but have a reputation as fin-nippers if kept in too small a group. A proper school disperses their internal bickering and largely prevents them from harassing other tank mates.

Emperor Tetra

Nematobrycon palmeri

Characins
5 cm Peaceful

A striking, robust schooling fish from Colombia. Unlike many tetras, they do not swim in a tight shoal, preferring to loosely associate while males stake out small territories to display to females. They feature a bold black lateral line and iridescent purple/blue hues.

Congo Tetra

Phenacogrammus interruptus

Characins
8.5 cm Peaceful

A stunning, large schooling fish native to the Congo River basin. Known for their iridescent rainbow colors and active swimming behavior. Despite their size, they are notoriously peaceful and can be skittish, requiring ample swimming space, dim lighting or floating plants, and peaceful tank mates. Avoid keeping with fin-nippers.

Rummy-Nose Tetra

Hemigrammus rhodostomus

Characins
5 cm Peaceful

Renowned as the tightest schooling fish in the freshwater hobby. They feature a bright red nose, a silver body, and a black-and-white checkered tail. They are excellent 'indicator fish'; their red noses will fade to pale pink if water quality drops or the fish are stressed. While there are three very similar species (H. rhodostomus, H. bleheri, P. georgiae) often sold under the same name, their care requirements are identical.

Bleeding Heart Tetra

Hyphessobrycon erythrostigma

Characins
7 cm Peaceful

A relatively large, deep-bodied tetra known for the distinctive bright red spot on its flank resembling a bleeding heart. They are active schoolers that require plenty of swimming space. While generally peaceful, they can become fin-nippers if kept in numbers fewer than 6 or in an undersized aquarium.