The serpae tetra (Hyphessobrycon eques) is a strikingly colored member of the Characidae family.

This freshwater fish is an aquarium favorite for its beauty and playfulness. They are also relatively easy to keep. Read on for more information.
At a Glance
Tank Size: | 20 gallons minimum |
Group Size: | 6 or more |
Water Temperature: | 72 to 79°F (22 to 26°C) |
pH: | 5 to 7.8 |
Hardness: | 10 to 25 dGH |
Lifespan: | 5 to 7 years |
Breeding: | Egg scatterer |
Adult Size: | 1.5 inches (3.8 cm) |
Usual Place in the Tank: | Middle to bottom |
In this article
- Natural Habitat
- Appearance and Biology
- Size
- Lifespan
- Behavior
- How many per gallon?
- Tank Setup
- Tank Mates
- Food and Diet
- Breeding
- Hardiness
- Frequently Asked Questions
- Final Recommendations
Natural Habitat
In the wild, serpae tetras are found in South America. They inhabit the rivers of the Guaporé region in Bolivia and the upper Paraguay River basin.
They prefer slower-moving waters found in ponds, lakes, and streams. These waters are darker and have plentiful vegetation.
Serpae tetras tend to stay near submerged roots and vegetation, where they can find both shelter and food.
Appearance and Biology
The first thing you notice about the serpae tetra is its brilliant color. Most of the species are a vibrant red-brown color, with shimmering scales that reflect the light.
This glittering, jewel-like appearance gives the serpae tetra its other common names: jewel tetra and red minor tetra.
Serpae tetras have a black spot just behind the gills. Their dorsal fin is square-shaped and dark black with a slight white edge.
The anal fin is shaped like an elongated triangle and the tail is forked. Both fins are red with black tips.
The vibrancy of the tetra’s colors can grow or fade depending on their health, diet, and environment.
The serpae tetra has a flat and tall body shape. There is not much variation between males and females of the species.
Females can be slightly less vibrant in color and rounder when carrying eggs.
Size
Expect your serpae tetra to grow to a length of 1.5 inches (3.8 cm) as an adult.
Lifespan
A serpae tetra can live anywhere from five to seven years. As with all fish, diet and environment can affect the lifespan of your fish.
Behavior
Serpae tetras do have a reputation as fin nippers. Keeping a group of six or more tetras together may reduce the odds of this happening.
This species can be a bit timid, so having plenty of hiding places may increase their comfort and limit any aggressive behavior.
Serpae tetra is a schooling fish. Your group of these tetras will generally stay in the middle to bottom tank areas.
They like to chase each other and will generally leave other fish alone. Having a tank with objects they can explore will keep them interested.
This species swims in a unique manner that is best described as “jerky.” They are fast swimmers that will speed for a short time, stop, and speed off again.
How many per gallon?
Because this species does best in a group of six or more, plan on a minimum tank size of 20-gallons.
This will allow space for these active swimmers to explore as well as room for plants and objects along the tank bottom.
Tank Setup
Setting up your fish tank to accommodate serpae tetras is simple.
Decorations

Line your 20-gallon tank with a dark, sandy substrate. Decorate with both live aquarium plants and driftwood or rocks along the edges to give your serpae tetras places to hide.
Consider java moss or Myriophyllum to provide shelter for your fish.

Keep the plants and decorations along the edges and the middle of the tank clear for swimming.

Water Conditions
Do not introduce your serpae tetra to a freshly set-up tank. They are sensitive to water parameter fluctuations, so a mature tank is best.
Using blackwater extract or peat can help keep the water soft and acidic.
Maintain the pH level between 5 and 7.8 and the temperature between 72 to 79 degrees Fahrenheit (22 to 26°C). Water hardness should be between 10 to 25 dGH.
Equipment
Install a canister filter that permits slow water movement. Use lower-powered lighting to better replicate their natural habitat.
Tank Mates
As we have mentioned, to keep your fish happiest and healthiest, they need other serpae tetras. A group of at least six is best.
Keep your tetras with other fast-swimming fish. They may nip at the fins of slower-swimming, long-finned fish.
Consider the following to pair with your serpae tetra:
- Barbs
- Danios
- Tetras (cardinal, black skirt, bloodfin, or neon tetra)
- Loaches or catfish
Avoid the following:
- Angelfish
- Bettas
- Freshwater snails
Food and Diet
Serpae tetras are omnivores. They will readily eat commercial flake and pellet food.
To keep them healthiest, augment their diet with freeze-dried, frozen, and live foods. Give them bloodworms or brine shrimp on occasion.
Breeding
To breed your serpae tetras, first prepare a separate tank with plenty of plants.
Consider adding a breeding mop. The serpae tetra is an egg scatterer, so the plants and mop will help to protect the eggs.
Keep the water pH level at 6.0 and raise the temperature to around 80 degrees Fahrenheit (26.7°C). Water softness should be between 6 to 8 dGH.
Condition your breeding pair with protein-heavy, live foods then move them to the breeding tank.
Watch for breeding behavior. The male will chase the female, who will scatter eggs as the male fertilizes them.
Remove the adults soon after this is complete as they tend to eat the eggs. The eggs will hatch in two days. At first, the fry will eat their egg sacs.
Once they become free swimming, you can feed them infusoria and baby brine shrimp.
Hardiness
While serpae tetras are not susceptible to any unique diseases, they can contract common freshwater fish diseases.
Ailments include ich, parasites, and fungal infections. You can prevent most of these by maintaining tank and water conditions.
Feeding your fish a healthy, varied diet improves their resistance to disease.
If your fish come down with any of these ailments, correct any water condition issues and use available medications.
Frequently Asked Questions
Are Serpae tetras aggressive?
Serpae tetras are a peaceful species and get along well with other fast-swimming fish. They do tend to nip at long-finned or slow-swimming fish.
Are Serpae tetras fin nippers?
While serpae tetras have a reputation as fin nippers, you can typically prevent this by keeping them in groups of six or more.
Will Serpae tetras eat shrimp?
Serpae tetras can eat shrimp. If you plan on keeping them in the same tank, add live plants to give the shrimp places to hide.
How big to Serpae tetras get?
Serpae tetras grow to a length of 1.5 inches (4 cm).
Will Serpae tetras school with other tetras?
Yes. Serpae tetras will school with other, fast-swimming tetras, such as the cardinal or neon tetras.
Final Recommendations
The serpae tetra is, without a doubt, a beautiful addition to a community aquarium.
Remember that for the best health of your fish, keep a group of at least six fish and feed them a varied diet.
The cost per fish online can vary from under $2 to over $4.
Plan your aquarium layout to give clear areas for swimming and planted areas for shelter.
Monitor water parameters and always introduce your fish to a mature tank.
What are the best tank mates you have paired with your serpae tetras?
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FAQs
Why is my serpae tetra losing color? ›
Too much of a temp change or something got to them. The tetra that has lost his color sounds to be another victim and is stressed out. Did you cycle the filter first? If no, that is the cause of your problem.
How many serpae tetras should be kept together? ›We recommend keeping a group of 5 to 7.
Keep an eye on the group and take out any aggressors that cause harm or make it hard for other fish to eat. Aside from other Serpae Tetras, these fish are compatible with other fast-moving peaceful fish. It's best to avoid slow fish that could be targeted for fin nipping.
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.
What is the behavior of a serpae tetra? ›Serpae Tetra Overview
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!
If your fish is swimming frantically without going anywhere, crashing at the bottom of his tank, rubbing himself on gravel or rocks, or locking his fins at his side, he may be experiencing significant stress. Talk to your veterinarian about treatment and look into what may be causing the stress and alleviating it.
How can I improve my tetra color? ›Feeding a high-quality diet is the leading way to enhance your fish's color and ensure their proper development. Other factors like a stress-free environment, good water conditions, and ample space in the tank also help enhance your fish's color.
What temp do Serpae tetras like? ›In the aquarium
Serpae tetras prefer water temperatures ranging from 72–79 °F (22–26 °C). They will generally do better and show off their best colors in soft, neutral to slightly acidic water. As with any other schooling fish, they thrive in large groups and should be kept in schools of at least six fish.
You should feed your fish two to three times daily. A few flakes per fish is sufficient. The fish should eat all the food in two minutes or less. Overfeeding can cloud your water and harm your fish.
Do Serpae tetras need a heater? ›They do best in soft, neutral to slightly acidic water with a pH of between 6-7.5 and temperatures between 72°-79°, so you may or may not need a heater for them. Serpae tetras do best in a more dimly lit environment and thrive in blackwater aquariums.
Are Serpae Tetras fin nippers? ›Serpae tetras are by nature fin nippers. They are only second to tiger barbs.
Are Serpae Tetras Hardy? ›
Serpae tetras are another on of those very hardy type larger tetras. Their distinctive red colour, hardiness and peaceful nature makes them an ideal choice for a tropical community aquarium, or even in a cold water set up in some parts where the climate is suitable.
Do tetras like other fish? ›Neon tetras will gladly zoom across the tank at dinner time, but it's also possible for bigger or bossier fish to push them out of the way and not let them get any food. It's better to go with a gentler, more laid back species that won't keep your neons from eating.
What do tetra fish like in their tank? ›They love tall plants like Ludwigia repens, Brazilian pennywort (also works as a floating plant), vallisneria, cabomba or Cryptocoryne wendtii. Neons also like floating plants like frogbit, dwarf water lettuce or red river floaters. They'll swim around in the roots that hang down into the water column.
Do tetra fish have memory? ›Summary: It is popularly believed that fish have a memory span of only 30 seconds. Canadian scientists, however, have demonstrated that this is far from true -- in fact, fish can remember context and associations up to 12 days later.
How do I know if my tetras are playing or fighting? ›Although tetras chase, jump and chase each other around in their bowl, they are just playing. You can tell signs of aggression when you notice one fish cowering in the corner and isolating itself from the school. You can stop aggression in tetras by providing sufficient food and space.
How do you destress tetras? ›- Change water frequently to keep nitrate and ammonia levels low. ...
- Check water temperature for consistency regularly to prevent stressful fluctuations.
- Provide an optimal filtration system like the Fluval Underwater Filter that captures debris and bacteria while ensuring proper oxygenation.
Unfortunately, by the time signs of ammonia stress are noticeable in fish – lethargy, appetite loss, gasping, inflammation of the gills, eyes or fins – it may be too late to take corrective action that can save the fish.
Do water changes stress out fish? ›Large water changes that include more than 60% water change, rinsing gravel, cleaning filter media lead to a complete, massive change in the water chemistry. Fishes when put in these new conditions, lead to temperature shock, stress, loss of appetite, and then death.
What enhances fish color? ›Mixed Seaweed – Seaweed is one of the few foods that enhance the full spectrum of colors, from red to blue, with each species excelling at one color more than others according to the color of the seaweed species itself. For example, green seaweed excels at blue enhancement and red seaweed enhances red coloration.
How do I make my fish more vibrant? ›Fresh vegetables like spinach, broccoli and romaine lettuce are also healthy sources of vitamins and minerals that will help your fish to achieve their natural coloration. Be careful when purchasing color-enhancing commercial foods because some foods will be better for your fish than others.
Do tetras like light or dark? ›
Like other tropical fish, tetras require the lights to be on in their tanks for 12 to 14 hours each day. This will help them to maintain a proper circadian rhythm. It's best to put your lights on a timer so that your fish can settle into a routine.
Do tetras like gravel or sand? ›Substrate: Both species of tetra are fine with any substrate if it is not small enough for them to choke on it. To ensure this doesn't happen, choose gravel that is too large to fit in their mouth, or choose a substrate with tiny particles, like sand, which won't really affect the fish if they ingest a bit of it.
How many tetras should you get at a time? ›Tetras are schooling fish and therefore they live happily in groups. Therefore, in the case of tetras, the classic rule of THE MORE, THE MERRIER applies literally. However, if you are the kind of person who believes in numbers, then a minimum of 6 tetra fish is recommended.
How do I know if I'm feeding my fish enough? ›A good rule of thumb when working out how much food to offer your fish is to see what they can dispose of per minute. If they finish all you offer in under a minute then you are giving the right amount of food. If it's taking more than a minute then you're definitely offering too much food.
How do I know if my fish is hungry? ›If your fish are digging around in the substrate, clearly searching for something, chances are that they are hungry. Fish that go to scavenge, but don't usually scavenge, or go inspect the top of the aquarium, something they wouldn't usually do, are both indications of hunger.
How many tetras can go in a 1 gallon tank? ›Due to their moderate size and hardiness, 3-4 tetras may be kept in tanks up to one gallon.
How can you tell if a serpae tetra is male or female? ›Males are generally smaller than females, but they have a vivid red color. Females tend to be a dull red and are round, especially during the mating process when they tend to become much fuller than males.
What disease is common in Serpae Tetras? ›Ich (White Spot Disease)
Ich is just about the most common disease that affects freshwater tropical and coldwater fish. Ich is caused by the parasite, Ichthyophthirius multifiliis, a protozoan that is usually present in most aquariums. Ich doesn't attack healthy fish.
What Are the Effects of Cool Water Temperature for Neon Tetras? Neon tetras need their temperatures between 72 and 78 degrees. 72 degrees F is the minimum water temperature a neon tetra can tolerate. Anything lower than this will harm your neon tetras.
Why are my tetras chasing each other? ›Neon Tetra chasing each other can be normal playful behavior – they are an energetic species. But it can also be a sign of showing dominance in a male-only aquarium, it might be a sign of mating, or it could be a sign of overcrowding. Keep tabs on your fish if they're chasing each other a lot.
Do tetra fish have teeth? ›
While their teeth do not protrude as their name implies, these tetras' teeth are more pronounced than other species, and they have pointed tips for tearing off scales. Bucktooth tetras are fast swimmers. Each fin is controlled by a separate set of muscles for precision swimming.
Do Serpae Tetras eat plants? ›– Serpae Tetra Diet
Serpae Tetras are omnivores; in the wild, they feed on plant matter and insect larvae. In captivity, they will happily eat anything you give to them. You can provide them with high-quality pellets and flakes.
Neon tetras may also exhibit a slight color fade when they spend a lot of time in darkness or at night. This color fade is normal and not usually cause for alarm.
Do tetras multiply? ›Even the smallest tetras are capable of producing several dozen eggs in one spawning attempt. When large groups are kept together for spawning, not all of the fish are actively involved. Those that are not breeding are usually eating eggs.
Do tetras need lots of plants? ›Do Tetras like lots of plants? While Neon Tetras do enjoy having spaces to hide, they also like plenty of open water in which to swim and school. Adding too many plants can restrict them, making them feel like they can't swim as freely as they want, which can cause them stress.
How many tetras can you put in a 10 gallon tank? ›As a general rule, you can keep 6 or 7 of them in a 10-gallon fish tank. Keeping any more than this is known as 'overcrowding' and is full of potential problems. But it should also be noted that neon tetra is schooling fish and prefer to be kept in larger numbers in bigger tanks.
What fish eat tetras? ›Freshwater "sharks"
Silver sharks are peaceful but grow to over a foot in length, are skittish, and will eat small fish like Neon tetras.
Therefore, a 20-gallon tank could comfortably hold 11.42 (20/1.75) tetras. You can either round that number up to 12 or 11 when stocking your aquarium.
Why is my tetra fish fading? ›The two main causes of color change in tetra fish are stress and disease. Extended exposure to bright light, loneliness, the presence of predators, and changes in water chemistry put a lot of stress on tetras. Pathogen-induced infections and diseases can also cause their colors to fade over time.
Why are my tetras turning white? ›If your tetra has white spots, it probably has ich. If your tetra has a white patch, it could be symptom of NTD, but it could also be a symptom of many other illnesses. NTD is fairly rare, so the white patch is more likely caused by a common bacterial or fungal infection.
Why does my fish look faded? ›
Aquarium fish that are stressed or ill are unlikely to display their optimal coloration and they may even fade in color as a result of stress. In order to prevent this from happening in your tank it is important to keep up a regular maintenance routine to ensure high water quality.
Why has my tetra changed colour? ›The fresh water fish neon tetra has the ability to change the structural color of its lateral stripe in response to a change in the light conditions, from blue-green in the light-adapted state to indigo in the dark-adapted state.
Do tetras lose color? ›Neon tetras may also exhibit a slight color fade when they spend a lot of time in darkness or at night. This color fade is normal and not usually cause for alarm.
Do tetras need constant light? ›Lighting Requirements
Like other tropical fish, tetras require the lights to be on in their tanks for 12 to 14 hours each day. This will help them to maintain a proper circadian rhythm. It's best to put your lights on a timer so that your fish can settle into a routine.
It is referred to as a bacteria bloom. The cloudiness should be gone within anywhere from two days to a couple of weeks. You can do a 10 to 15 percent partial water change and gravel vacuuming after a week to speed it up.
Why did my fish suddenly turn white? ›Fungal, bacterial, and parasitic infections are the main causes. Typical diseases are known to cause goldfish to turn white include the ich and Malawi bloat. Keep an eye on how the white color changes look like. Fatal illnesses tend to cause deadly white erosions due to conditions like dropsy.
Why is my fish covered in white? ›Fungal infections are one of the most common disorders for fish. Fungal spores naturally populate fish tanks, but sick, stressed or injured fish can cause a dangerous increase. These infections manifest as a white cotton-wool-like growth on the skin, mouth, fins or gills.
How can you tell if a fish is dehydrated? ›Your best bet is to check on your fish as it dries and test it. Look out for it turning firm, feeling completely dry, and yet still pliable. If you see any hints of moisture still on the fish, keep drying. If it falls apart when you bend it to test for how pliable it is, then you have dried it for too long.
Why did my pet fish change colors? ›As a fish swims over a light substrate the chromatosomes are transported into the centre of the cell (aggregation) resulting in the fish appearing paler. Swimming over a dark substrate results in the chromatosomes spreading out throughout the cell (dispersal) which leads to a darkening of the fish's colour.
What does dropsy look like in tetras? ›Scales protrude from the body, giving the appearance of a pine cone. This symptom is a classic indication of a severe infection.
Why does my tetra look pregnant? ›
On a closer glance, you notice one of your neon tetra seems to have a larger belly than the rest. Could she be pregnant? From a biological standpoint, the answer is no. Tetras are an egg-spawning species; however, that swelling in your tetra's belly may indicate the fish is carrying eggs and is ready to spawn.