Serpae Tetra

Red Minor Tetra, Jewel Tetra, Callistus Tetra

Family: Characidae Serpae Tetra, Hyphessobrycon eques, Red Minor Tetra, Jewel Tetra, Callistus TetraHyphessobrycon equesPhoto © Animal-World: Courtesy David Brough
Latest Reader Comment - See More
Ok well I have a tetra and he is in with three Molly's and four little angel fish and also a gormi at first he was grate and he didn't bother any of my other fish... (more)  Caitlin

The Serpae Tetra has a contrasting red to black coloring and looks like its sprinkled with jewels!

The Serpae Tetra Hyphessobrycon eques is a beautiful fish and truly looks like it sparkles with jewels in the aquarium. A school of of these tetras are real eye catchers. They have a beautiful reddish color that picks up flashy jewel type highlights. They are also adorned with a large, almost diamond shaped black spot, just behind the gills.

A number of very different common names are used to describe this decorative tetra. These include Red Minor Tetra, Jewel Tetra, Callistus Tetra, Red Serpa, Blood Characin, Blood Tetra, and even Red Phantom Tetra. This fish is quickly recognized as a Red Minor Tetra while these other names have more of a story.

This tetra used to be described scientifically as Hyphessobrycon callistus. Today that is a junior synonym but from it comes the term 'callistus' meaning 'very beautiful'. So this characin became known as Callistus Tetra. Also from this term, along with its flashy appearance, it became known as the Jewel Tetra. Another junior synonym, H. serpae, led to the not so flashy names of Serpae Tetra and Red Serpa. There is also a variety with long fins usually referred to as Long Fin Red Minor Tetra or Long Finned Serpae Tetra.

The names Blood Tetra and Blood Characin are more curious. They come from it being a member a of a complex of `blood' tetras'. This loosely defined complex refers to a wide range of tetras with a base body color of red, that are often hybridized for the aquarium trade. Finally, some authors will refer to this fish as the Red Phantom Tetra. So be careful not to confused it with Hyphessobrycon sweglesi, which is more commonly accepted as the Red Phantom.

A school of Serpae Tetra are real eye catchers in the aquarium. They are also easy to care for. The Serpae Tetra are usually fine in a community situation, however they are not always easy to get along with. Smaller fish especially may become the target of relentless harassment and fin nipping. They will do best with the company of their own kind, and a school of at least six is needed. They can also get along fine with other similar sized and active fish. Once they are established they are very hardy and long lived, and they are easy to breed.

For more Information on keeping this fish see:
Guide to a Happy, Healthy Freshwater Aquarium

Geographic Distribution
Hyphessobrycon eques
Data provided by
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Characiformes
  • Family: Characidae
  • Genus: Hyphessobrycon
  • Species: eques
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Serpae Tetra - Quick Aquarium Care
  • Aquarist Experience Level: Beginner
  • Size of fish - inches: 1.6 inches (3.99 cm)
  • Minimum Tank Size: 20 gal (76 L)
  • Temperament: Peaceful
  • Aquarium Hardiness: Very Hardy
  • Temperature: 72.0 to 82.0° F (22.2 to 27.8° C)
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Habitat: Distribution / Background

The Serpae Tetra Hyphessobrycon eques (previously Hyphessobrycon callistus) was described by Steindachner in 1882. They are found in South America, particularly in upper Paraguay and the Madeira and Guapore regions. This species is not listed on the IUCN Red List. Other common names they are known by include Red Minor Tetra, Jewel Tetra, Callistus Tetra, Blood Characin, Blood Tetra, Red Serpa, Callistus, and some authors refer to them as a Red Phantom Tetra. Long finned Serpae Tetra variety has been developed in captivity, also called Long Fin Red Minor Tetra.

They frequently inhabit densely vegetated and stagnant waters that include tributaries, ponds, and small lakes. They stay close to the surface among the plants and feed on worms, crustaceans, insects and plant matter. They are a gregarious species, living in groups, but will frequently bite each other's fins during feeding.

  • Scientific Name: Hyphessobrycon eques
  • Social Grouping: Groups
  • IUCN Red List: NE - Not Evaluated or not listed


The Serpae Tetra is a deep bodied fish with the typical tetra shape. It is a somewhat elongated oval from the side view and compressed laterally.This fish will generally reach about 1 1/2 inches (4 cm) in length and has a lifespan of generally about 3 - 7 years. Its body has a beautiful reddish color that picks up flashy jewel type highlights. There is a large, almost diamond shaped, black spot behind the gills. Their fins are mostly black with tips of white. It has also been developed in a long finned variety, usually referred to as Long Finned Serpae Tetra or Long Fin Red Minor Tetra.

  • Size of fish - inches: 1.6 inches (3.99 cm)
  • Lifespan: 7 years - These fish generally have a life span of 3 - 7 years, though some have reportedly lived up to 10 years.

Fish Keeping Difficulty

The Serpae Tetra is a very durable fish that is great for the beginner fish keeper. Although these fish are easy to care for they do have some traits that are less then ideal and can make them a poor choice for tanks with passive inhabitants. These fish can be very boisterous and constantly harass the others in the tank. This in turn can lead to stress issues for shy or gentle tankmates.

  • Aquarium Hardiness: Very Hardy
  • Aquarist Experience Level: Beginner - This is an excellent beginner fish as it is both robust and tolerant of a wide range of water conditions.

Foods and Feeding

Since they are omnivorous the Serpae Tetra, or Red Minor Tetra will generally eat all kinds of live, fresh, and flake foods. To keep a good balance give them a high quality flake food everyday. Feed brine shrimp (either live or frozen) or blood worms as a treat. These tetras like several feedings a day, but offer only what they can consume in 3 minutes or less at each feeding.

  • Diet Type: Omnivore
  • Flake Food: Yes
  • Tablet / Pellet: Yes
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet
  • Meaty Food: Some of Diet
  • Feeding Frequency: Several feedings per day

Aquarium Care

Serpae Tetras are not exceptionally difficult to care for provided the water is kept clean. Aquariums are closed systems and regardless on size all need some maintenance. Over time decomposing organic matter, nitrates, and phosphate build up and the water hardness increases due to evaporation. To combat these ever changing conditions water should be replaced on a regular basis, especially if the tank is densely stocked. At least 25 - 50% of the tank water should be replaced every other week.

  • Water Changes: Bi-weekly

Aquarium Setup

These fish are fairly hardy and a school of six will do best in about a 20 gallon aquarium. Adding aquarium safe peat to the tank will simulate the black water that these fish inhabit in nature. They need a high quality filter but make sure it does not create too much current as this fish prefers more sluggish waters. The lighting in the tank should be dim as they come from areas that have dense forest cover.

The aquarium should be heavily planted around the sides and back and have plenty of open water for swimming in the front. A few hiding places would be appreciated. Woodwork and floating plants will make them feel comfortable. A biotope tank is preferred by the Serpae Tetra. Using a substrate of river sand and scattered drift wood and twisted roots with a hand full of dried leaves make a good natural feel to the tank. Make sure to remove and replace the dried leaves every few weeks.

  • Minimum Tank Size: 20 gal (76 L)
  • Suitable for Nano Tank: Yes
  • Substrate Type: Any
  • Lighting Needs: Low - subdued lighting - A tank with a dark, shadowy set up and low lighting will bring out their best coloration.
  • Temperature: 72.0 to 82.0° F (22.2 to 27.8° C) - They should not be kept below 77° F (24° C) at any time.
  • Breeding Temperature: 75.0° F - Breeding temperatures between 75.0 to 82.0° F (24 to 27.8° C).
  • Range ph: 5.5-7.5
  • Hardness Range: 5 - 20 dGH
  • Brackish: No
  • Water Movement: Moderate
  • Water Region: All - These fish will swim in all areas of the aquarium but will tend to spend a lot of time close to the top if their are floating plants.

Social Behaviors

The Serpae Tetra can be a good community fish but only if kept with fish that are the same size or bigger. Smaller fish may become targets, getting harassed and getting their fins nipped. It is also not advisable to keep this fish with slow swimming long finned tank mates. Good choices are similar sized tetras, rainbowfish, larger rasboras, barbs and danios. They do best when kept in pairs, or in schools of at least 5 - 6 individuals. Groups will make them feel comfortable and help diffuse some of their pugnacious tendencies. If two males are kept together they will act as if they are fighting but will not actually hurt each other. Tetras can be easily spooked into hiding so situate the tank appropriately.

  • Venomous: No
  • Temperament: Peaceful
  • Compatible with:
    • Same species - conspecifics: Yes - They do best in a school of 6 or more of their own kind.
    • Peaceful fish (): Safe - This fish may bully smaller and slower moving fish. Keeping it in a school will make it more comfortable and diffuse some of its pugnacious tendencies towards other fish.
    • Semi-Aggressive (): Threat
    • Aggressive (): Threat
    • Large Semi-Aggressive (): Threat
    • Large Aggressive, Predatory (): Threat
    • Slow Swimmers & Eaters (): Monitor
    • Shrimps, Crabs, Snails: Safe - not aggressive
    • Plants: Monitor - May nibble on some aquarium plants.

Sex: Sexual differences

The males are brighter colored and the dorsal fin of the male is almost solid back and the females lack the color in the lower part of the fin. The females are fuller bodied than the males.

Breeding / Reproduction

These tetras are egg layers and easy to breed. Provide a small breeding tank of about 3 to 5 gallons, and condition the pair. Provide bunches of fine-leaved plants such as Myrophyllum or artificial spawning grass. Recommended conditions: temp: 75.0 to 82.0° F (24 to 27.8° C) , pH 5.5 - 6.8 (6.8 is best), and hardness of 10° dGH. See a general description of how to breed egg layers in Breeding Freshwater Fish: Characins.

  • Ease of Breeding: Easy

Fish Diseases

The Serpae Tetra is very hardy and disease is not usually a problem in a well maintained aquarium. That being said there is no guarantee that you won't have to deal with health problems or disease. Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance.

A good thing about the Serpae Tetra is that due to their resilience, an outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. When keeping more sensitive types of fish, it is common for all fishes to be infected even before the first warning signs can be noticed. The best way to proactively prevent disease is to give your Flame Tetra the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. Stressed fish are more likely to acquire disease.

As with most fish they are prone to skin flukes, parasitic infestations (protozoa, worms, etc.), ichthyobodo infection, parasitic infestations (protozoa, worms, etc.), bacterial infections (general), and bacterial disease. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Serpae Tetra, or Red Minor Tetra, is readily available in pet stores and online, and is reasonably priced. There is also a longfinned variety that has been developed and is often available. This variety is usually referred to as Long Fin Red Minor Tetra or Long Finned Serpae Tetra.


Author: David Brough CFS, Jeremy Roche
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Lastest Animal Stories on Serpae Tetra

Caitlin - 2012-11-04
Ok well I have a tetra and he is in with three Molly's and four little angel fish and also a gormi at first he was grate and he didn't bother any of my other fish until now iv had him for about five weeks and know he is starting to annoy me he is distroying my other fishes fins and I'm about ready to take him back to the pet store.  I just don't know what to do.  I'm trying to get another tank but if I do he will be all alone so what do I do what do I do untill I get another tank and what do I do when I get the tank what fish do I put him with if he will just destroy their fins? Please help I'm getting a headache

  • Jeremy Roche - 2012-11-05
    Try setting up nice sinle species tanks with it.
  • Bella - 2014-11-26
    If you are talking about the serpae tetra, they are a schooling fish. They must be kept in groups of 6+ to feel safe and secure. Your little guy is all by himself (herself) and is acting out because he (she) is stressed and scared.
Nate - 2010-12-22
I added 4 Red Serpa Tetras to my 75 gallon tank and they started of shoaling together very well. Now two weeks later they are constantly nipping at each other. I have 7 red wag fry (three months old) 3 adult red wags. I also have one dalmatian molly (the other two didn't survive after a case of ich). They don't bother any of the other fish including the fry. Now one of the Tetras has a huge chunk ripped out of his top (dorsal?) fin. Any way to tame these once calm fish?

  • bill - 2011-05-01
    I had same problem with four. Increased the number to six and the problem is gone.
  • Jason - 2013-12-02
    Well I have 20 serpraes in my 50 gallon. I notice that serpraes like to nip at each others and other fish's fins. They do that because if they are nipping each other they are establishing ranks as the small 1 inch serpraes are getting bossed around by my 2 inch ones. Generally keep serpraes in a species only tank as then they won't nip other fishes. Also one thing: ESPECIALLY DO NOT KEEP THEM WITH LONG FINNED FISH! I learned that the hard way my pair of phillipine blue zebra angels got some of their fins nipped by my serpraes. And you should add more serpraes, the more serpraes the less fin nipping as my serpraes don't bother my discus because they are busy nipping each other. Honestly tetras are fish that can easily be overcrowded, you could have 10 inches of tetra per 1 gallon (that's why they have like 100 tetras in a 10-15 gallon tank in the LFS and the major fish stores too).
  • Reggie - 2014-06-25
    100 tetras in a 10 gallon tank? No offense but very bad advice, my friend. 10 inch per gallon as well as 1 inch per gallon are both poor rules. A 10 inch Oscar , 100 Small tetras need a 125 gallon tank, 100 Large Tetra species need 200 gallons at the very least.
  • kaysi - 2014-08-19
    Most pet stores do keep there fish in smaller tanks but technically it's one giant tank because they are all connected to the same water source and filer
Jason - 2013-12-02
I have 20 serpraes in a 50 gallon planted with 4 discus. The serpraes are a nice fish, the more you get the less fin nipping you get on other fish generally so my serpraes don't bother my discus at all as they are busy nipping each other, but they don't get hurt that much though but I put fin rot medicine every 2 weeks to be safe.

Anonymous - 2012-06-08
I've had my Red Minor Tetras for about two weeks and one of them died this morning, so I took it back to the pet store and got another one but since that one has been home it has layed at the bottem of the tank and only swims a little at a time or won't even move for a long time. WHAT'S GOING ON! HELP!

  • symbol - 2012-08-30
    How large is your tank? How long as it been set up? Do you know if it's cycled? (If you're not sure what I mean, look for some information on the nitrogen cycle as it pertains to aquariums. There are lots of good articles out there.) Also, how many fish are in your tank? (And what kind of fish/how big are they?) Do the other fish seem to be behaving normally? Have you done any water changes recently or added anything new to the tank? Did the new fish seem to be swimming/behaving normally when it was in the tank at the store? Did you notice any symptoms in the other fish before it died? Having some or all of this information will help people tell you what might be wrong with your fish. As it is, it's very difficult to tell what the problem could be.
  • Jeremy Roche - 2012-08-31
    First step is always to test your water.  Pet shop will usually do it for you!