Serpae Tetra:Care Guide, Breeding, Tank Size and Disease

Serpae Tetra: A Quick Summary

The Serpae Tetra (Hyphessobrycon eques) is a small, colorful fish native to South America. It is a popular choice for aquariums due to its bright red and silver coloring and peaceful nature. The Serpae Tetra is a hardy fish that is easy to care for, making it a great choice for beginner aquarists.

Serpae Tetra Overview

Serpae Tetras are a bright crimson-colored, tropical freshwater species of fish that are not only popular because of their beauty, but also because they are quite easy to care for, making them the perfect addition to your aquarium if you’re new to the fish scene. They are also known by multiple other names such as blood characin, Callistus, Callistus tetra, jewel tetra, red minor tetra, red serpae, Serpa tetra, etc.

They are native to Brazil, northern Argentina, Paraguay and can be found quite easily in ponds, streams, or generally backwaters.

If you want to observe Serpae Tetras are on their best behavior then put them in a tank along with a couple of other tetras, as they tend to be a tad bit aggressive to other, slower-moving fish species, and watch them explore their surroundings in schools of bright red!

Information ChartSerpae Tetra
Scientific Name:Hyphessobrycon eques
Care Level:Easy
Colour:Red, Reddish-Brown
Lifespan:5-7 years
Size:1.75-2 inches
Minimum Tank Size:20 gallons
Temperature:72°F to 79°F 
Water Conditions:pH 5 to 7.8
Tank Mate CompatibilityOther Serpae Tetras

Serpae Tetra Appearance

Serpae Tetra

The most visually striking feature of the Tetras is naturally their flame-red hue, with some of them also taking on a slightly reddish-brown color. Some of them may also have a variation of the shade and look olive-brown as well. As they belong to the Characin family, they have embodied a similar shape and frame: they appear like a trapezoid.

A striking feature about these fish is the black outline on their fins which, in turn, is outlined by a white stripe on their dorsal fins, making them look dazzling. It almost makes them sparkle underwater. A fun fact about these hues is that even though the base color of the fish remains the same, the hues on top change due to underlying reasons, such as environment or diet. These colors, however, fade a little as the fish grows old. Another noticeable thing about their appearance is that the female Serpae Tetra are plumper and less shiny and brightly colored than their male counterparts.

Lifespan of Serpae Tetra

Serpae Tetras typically live up to 5 to 7 years in captivity. Their life expectancy is quite standard but can be impacted by the common factors surrounding fish care such as water temperature, diet, etc.

Serpae Tetra Size

The typical Serpae Tetra typically grows up to 1.75 inches and sometimes up to 2 inches for the largest specimens. These are usually very small fish, and may not even grow up to 1.75 inches under stringent living conditions.

Natural Habitat and Origin

The Serpae Tetra Hyphessobrycon eques (previously known as Hyphessobrycon Callistus) and was described by Steindachner in the year 1882.

Serpae Tetras are native to the Amazon basin and are typically found in Argentina, Paraguay, and Brazil river basins. They are quite commonly bred as captives, but the species is not endangered. They usually prefer slow and quiet backwaters, where they can find food and safety, under vegetation or tree trunks, etc.

Due to their bright, crimson-colored body, they are often confused with but are very different from, the red phantom tetra, also known as, Hyphessobrycon swegles.

Serpae Tetra Care and Tank Set-up

Serpae Tetra Tank Size and Specifications

Optimum Tank Size for Serpae Tetra

The recommended tank size for Serpae Tetra is 20 gallons.

Serpae Tetra is quite durable and hardy and a school of 5 to 6 can easily live and thrive in a tank that is about 20 gallons. Something that can be done to make sure that

Tank Shape for Serpae Tetra

Any kind of a 20-gallon tank is fine for Serpae Tetras, and they are even suitable for nano tanks.

Filter Type

Serpae Tetras don’t have any strict requirements for filter types. A standard canister filtration system, even an air-driven sponge filter or hang-on-back unit will work. As long as it provides gentle filtration, it will do fine.


Since the Serpae tetras natively belong to the Amazon basin, an aquarist might need to replicate the environment and so, starting with a dark, sandy substrate is the best option, usually, the one that replicates dark or muddy waters. The water body in the Amazon basin usually has a residue floating at the bottom, and the substrate will help mimic that to create a comfortable atmosphere for Serpae Tetra.

How Many Serpae Tetra in 20 Gallon Tank?

In a tank of 20 gallons, the best number would be 5 to 7 Serpae Tetra as they will chase and develop a hierarchical order within themselves. Overcrowding may lead to diseases and with nippy fish such as Serpae Tetra, the best amount would be 5 to 7, which can be increased slightly if the tank size is bigger.

Water Parameters

Water Temperatures

The ideal water temperature for Serpae Tetra is between 72°F to 79°F. Out of the range, 78-79 degrees would be the perfect temperature for Serpae Tetra to thrive. The temperature should not go below 24 degrees as that might prove fatal to the fish. The water needs to be changed bi-weekly.

Water Flow Rate

Even though the Serpae Tetras can be easy to care for, they will fall ill if the water quality is poor, or if the water flowing rate is too high as they prefer slow-moving waters, which is where they thrive best. An aquarist might need to be extra careful of this, or invest in a good-quality water filter that can regulate the water flow rate so as not to disturb the Serpae Tetras.

pH Level

The perfect pH level for Serpae Tetras should be between 5 to 7.8. Since the natural environment of a Serpae Tetra is warm and slightly acidic, the pH level mustn’t fluctuate, as they are quite sensitive to these fluctuations.

Water Hardness

The appropriate water hardness for Serpae Tetras is 5 to 20 dGH. The Serpae Tetra is a species that cannot tolerate brackish water at all, and so getting the water hardness correct becomes vital.

Serpae Tetra Tank Landscape

The key to keeping any creature happy is to create an environment that resembles home the most. For Serpae Tetra, that environment is the dark, muddy water of the Amazon basins, densely packed with vegetation and organic debris floating around, usually close to a large surface in the dark like the roots of a tree, or undergrowth. This is the environment that an aquarist should hope to create to keep its Serpae Tetras happy.

Serpae Tetra Tank Landscape

Best Plants for Serpae Tetra Tanks

Plants are of the utmost importance to Serpae Tetras. For them, plants not only provide a snack but also a place that replicates the feeling of safety and shelter. Choosing the right plants (and the right places to put those plants) is very important to make the fish feel cozy. Some plants that work best are Java Moss and Myriophyllum because they provide shelter without taking up too much space with their leaves and letting the fish move around. These plants need to be arranged sparsely around the edges of the tank but not in the middle to leave someplace for the fish to move around.

Worst Plants for Serpae Tetra Tanks

Any plants that do not have fine leaves, or spawning, or spindly mops should not be considered for a Serpae Tetra tank, as they leave no space for the movement of the fish. Plants like poison ivy or any plant that we generally would not touch without consultation from an expert are a strict no-no.

Decorations for Serpae Tetra Tanks

Merging these plants with other items for decor such as driftwood, leaf litter or pieces of rock is a great addition to the tank. Adding items like a small plant or a colorful rock keep the fish engaged, as they love playing hide and seek around these massive structures! Decorative items like plants or rocks can also be useful to hide the mess the fish create, or sometimes to just soften the rush of water, if your filtration system has a strong flow of water coming out of a tube, in which case, a plant will act as a good deterrent for the current.

Lighting for Serpae Tetra Tanks

Lighting within the tank should be minimal to best replicate the dark, mossy, and gloomy atmosphere that the fish are used to. Their natural environment is forested, and having a brighter light can be detrimental to their comfort.

Feeding Serpae Tetra

Long Fin Serpae Tetra

Best Diet for Serpae Tetra

Since Serpae Tetras are omnivores, they normally eat all kinds of live, fresh as well as flake foods such as fish, shrimp, worms, etc. They even eat tablets or pellets. To make sure that they’re getting a good amount of nutrition, we must make sure that they are getting high-quality flake food. As a treat, they can also be fed brine shrimp which can be either live or frozen or even blood worms.

How Often Should You Feed Serpae Tetra?

Serpae Tetras need us to feed them multiple times during a day, but an aquarist must keep in mind to only give them food which they can consume in 3 minutes or less at each feeding, as otherwise, they would be overfed.

Serpae Tetra Behaviour and Temperament

Is Serpae Tetra societal or lone in nature?

Serpae Tetras are usually peaceful fish, and they are quite societal and do not like living alone at all. This is why, they should always be kept in schools, and they get along very well with peaceful tank companions. They are very compatible with other fish that move fast and this should be considered while getting tank mates for them.

Serpae Tetra Tank Mates

Ideal Serpae Tetra Tank Mates

Serpae Tetra with Tiger Barbs

Serpae Tetras are very peaceful in general and should be kept in a school of five to six in a 20-gallon tank, increasing in number as the tank gets bigger. In smaller groups, however, they show signs of nipping the other fish’s fins, and that aggression, as mild as it is, is often directed towards its kind. This is very true especially if this happens during feeding times. Because of such behavior, the ideal tank mates for Serpae Tetra would be other Serpae Tetra, or other kinds of ‘active’ fish (as Serpae Tetra tend to bully and nip the slower moving fish), or it could be fish of larger sizes such as:

Bad Tank Mates for Serpae Tetra

Bad tank mates for Serpae Tetra would be fish with long, flowing fins, or the fish that move slowly, as that may result in a lot of aggression. Fish such as angelfish and bettas should be avoided for Serpae Tetra tanks:

Breeding Serpae Tetra

Even though breeding Serpae Tetra is quite an easy process, it has to be done in a different tank, as this species does not exhibit any parental instincts of protection and care and act as a danger to the baby fish.

To breed Serpae Tetra, a different tank needs to be prepared which is decorated similarly with the embellishments to create a cozy and comfortable habitat for the newborns. This tank can be populated with a lot of plants, and an aquarist should consider using a breeding mop for this process.

Since Serpae Tetras are egg-layers, they will be sure to scatter their eggs throughout the tank and their immediate environment, which will result in the plants and the vegetation around it to catch them and protect them until they hatch. While this process takes place, it is important to keep the water temperature a little warmer (around 80 degrees Fahrenheit to act as a catalyst), and we should keep the water flow as gentle as possible. The pH balance needs to be maintained at a steady 6.0.

Before we decide to move our adult Serpae Tetra into the breeding tank, we must prepare them with some protein-rich snacks. Even frozen food or live food will be vital to facilitate the spawning process to move quicker.

The indication that the adult Serpae Tetras are ready to breed is that the female fish will get plumper. Once this happens, the male fish will chase them around, causing the female to scatter the eggs throughout the immediate environment. This usually happens early in the morning. Post this, it will be up to the male to fertilize those eggs. This is quite a steady process, and most of the time, hundreds of eggs are laid at once.

As mentioned earlier, since the Serpae Tetras do not have any parental instincts, they will try to eat their eggs immediately after they’re scattered, and it is here that an aquarist must act quickly to separate them from the eggs. The adult Serpae Tetra must be removed after they’re done and placed back in the other tank.

The eggs are very sensitive to light and so we can switch off all the lighting in the tank while we wait for the eggs to hatch.

The breeding process will be over in approximately two days when the eggs are ready to hatch. The babies tend to eat their egg sacs. They grow a bit more until they can swim leisurely, during which period, to facilitate the growth, we can provide them with items such as brine shrimp or infusoria. We can also opt for commercially prepared fry food.

The baby fish need to be kept separately in the tank until they can defend themselves and eat dry flake food on their own.

Serpae Tetra Breeding Level – Easy

Serpae Tetra Sexual Dimorphism?

To distinguish between male and female Serpae Tetra, we must notice the difference in their hues. Among the Serpae Tetra species, the males are more brightly colored than their counterparts and their dorsal fin is almost completely black. On the other side, females are slightly dull-colored, or not as vibrant and they are far more plumper than males are. Females also lack color under their fins.

Serpae Tetra Common Diseases and their Treatment

Infection Symptoms on Serpae Tetra

Serpae Tetras are not prone to getting specific diseases apart from very common diseases due to being freshwater fish, such as skin flukes, fungal infections, parasitic infections, etc. These can easily be prevented by making sure the water they are kept in is suitable for them and checking their water requirements from time to time to avoid any such ailments. Reading up on common tank ailments is also quite useful for any aquarist dealing with Serpae Tetra. Usually, even if an outbreak does occur, due to the amazing resilience that Serpae Tetras possess, they can be limited to just one or two fish. The ultimate treatment and prevention of disease among your Serpae Tetra is to stay on top of water tank hygiene and giving them a well-balanced diet.

Facts About Serpae Tetra

  • Serpae tetras are found mostly in South America.
  • They have many names such as Red Minor Tetra, Jewel Tetra, Callistus Tetra, Blood Characin, Blood Tetra, Red Serpa, Callistus, and sometimes are confused with Red Phantom Tetra.
  • A long-finned Serpae Tetra variety developed in captivity is known as Long Fin Red Minor Tetra.
  • They have a small, diamond-shaped black mark next to their gills.
  • The red color of the fish and the white hue on the end of its black fins, makes it glow and glitter in the light like a jewel.
  • The Serpae Tetra is a very hardy fish and hence a beginner-friendly fish.
  • The Serpae Tetras can grow up to 1.4 inches in size.
  • The Serpae Tetras can live up to 4 to 5 years in proper care.

Is Serpae Tetra Right for You?

Author’s note: Serpae Tetras are right for everyone as they are peaceful for a large part, and make for quite active fish-watching. It is fun to see them exploring their tank, and they thrive when in large schools. Overall, they are the best addition to any home setting or aquarium environment due to their animated and sprightly nature.

Serpae Tetra


Are Serpae Tetras Hardy?

Serpae Tetras are quite hardy and if the tank is well-maintained they generally do not suffer from diseases. This makes them quite beginner-friendly.

How many Serpae Tetras should be kept together?

Ideally, one can keep up to 5 to 7 Serpae Tetras together in a small tank.

Why are my Serpae Tetras chasing each other?

Serpae tetras are mildly aggressive and chasing each other is quite normal, as they are trying to establish a hierarchical dominance. Some other reasons could also be the small size of the tank, or that they are mating, etc.

Will Serpae Tetra school with other tetras?

Yes, they do school with some species of tetras like larger tetras, or even barbs.

Can Serpae tetras live with Tiger barbs?

Serpae Tetras can live with Tiger barbs but only when they are equal in numbers, as they both are quite nippy. One must only keep them both in schools or not at all.

How many Serpae Tetras Can I put in a 20-gallon tank?

As mentioned earlier, Serpae tetras can be kept in a group of 5-7, even in a tank as small as 20-gallons.

Do Serpae Tetras eat algae?

Yes, Serpae Tetras are omnivores and do eat algae, even planktons, and small insect larvae.

Can Serpae tetras live with bettas?

No, that is not recommended as Serpae Tetras are very nippy and they might nip the fish slower than them, such as bettas.

Do Serpae tetras breed easily?

Yes, Serpae Tetras are quite easy to breed, however, certain tank requirements need to be met. Please refer to the section above to understand it in more detail.


Serpae Tetras are bright, beautiful, and easy to care for, making them the best for anyone who is a beginner in fish care, and even if you just follow two things on this guide – the water and diet requirements – your Serpae Tetras are sure to live longer and healthier lives!


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