Bloodfin Tetra Stats InfographicThe Bloodfin Tetra, also known as the red finned tetra, is one of the most popular tetra freshwater fish species. Like its cousins the Cardinal, Penguin, and Neon Tetra, the Bloodfin

Tetra is kept for its attractive pattern, gentle nature, and wide availability. Schools of Bloodfin Tetra make colorful, shimmering displays in freshwater aquariums.

Tetras are one of the first species that new aquarium keepers explore. They are available through most fish supply outlets and inexpensive to acquire or replace. Once keepers have learned Bloodfin Tetras, moving up to larger, more colorful, and complex species is very manageable in species or community tanks.

This article will teach you about the background of the Bloodfin Tetra and how to care for and maintain the species.


Listed tank sizes are the minimum
Size: Up to 2 1/2 inches (8 cm)
Tank: 20 Gallons for a school of 20
Strata: Top, middle
PH: 5.5 to 7.0
Hardness: Soft to hard, dH range 4-20
Temperature: 73 to 82 F (22-28 C)
Order: Cypriniformes
Suborder: Characiformes
Family: Characidae
Genera: Aphyocharax

Origin and Appearance

Bloodfin tetra fishBloodfins are one of many thousands of species of collectible fish that come from South America. They are a social, schooling species that is found extensively in the Amazon Basin from Peru into Western Brazil. Their habitat is slow-moving waters. They tend to stay in small schools of six to eight fish.

Like many of the tetra species, the Bloodfin or red tail tetra moves back and forth from rivers to the flood lands during the rainy season for breeding and shelter. This highly tannic water can be stained almost to the color of coffee at times because of the heavy amounts of rotting vegetation on the bottom of the waterways. It is in these low light waters that the Bloodfin Tetras can be at its most vivid pattern.

As floodwaters recede, Bloodfin Tetras follow them back to their normal river habitats. The species form shoals of fish ranging from the hundreds to the thousands and make sheets of vivid color in the water that is quite amazing to see.

The Bloodfin Tetra is one of the most appealing tetras. Their primary color is a glassy silver, so much so that the fish is sometimes marketed as the glass bloodfin tetra. The scales have an iridescent finish. As they swim, you will notice flashes of green and blue as light reflects off their body.

What stands out on the Bloodfin Tetra is their fins. As their name suggests,  they have a brilliant, almost neon red color that covers their dorsal, anal, adipose, and tail fin. It offers a stark contrast to the rest of their body and makes the fish stand out in any environment.

Typically, the red will cover most of the fins. The only part that’s not red is the tips, which are usually transparent. These are ray-finned fish. However, the rays are quite delicate and difficult to see compared to other species.

Unlike other tetras, it can be difficult to tell males and females apart. You won’t find too many differences between them. Sometimes, mature males will develop visible gill glands and small hooks on the anal fins. But sometimes they will not.

The best way to determine sex is to take a look at their coloration. The Male Bloodfin Tetra tends to be more vibrant than females. Females also tend to be plumper. This is especially true around breeding time.

In the home aquarium, the Bloodfin Tetra can grow to 2.5 inches and live to nearly 5 years. It is one of the larger tetra species.


The Bloodfin Tetra is a species that does very well in captivity under general conditions. It is easy enough to care for that it makes a great first fish for new hobbyists.

The methods you learn from caring for Bloodfin Tetra will help you grow your experience as a fish keeper.

The species can tolerate a wide range of temperature, pH, and hardness and can thrive quite well in aquariums as small as 20 gallons.

– Water Temperature

The ideal Bloodfin Tetra water temperature is 73 to 82 F (22-28 C). Keepers should maintain a water hardness of 4.0 to 20.0 and a pH of 5.5 to 7.0. This is easily done with most tap water as long as it is free of chlorine and other chemicals.

Unless you live in very cold climates, most homes will have an ambient temperature within their target range and no heating may be required.

A standard filtration sized to match your aquarium is sufficient to maintain a light water flow and acceptable oxygen levels. Underground filtration systems work well for this purpose.

Scaling up to a hundred gallon or larger tank presents the opportunity to have schools of Bloodfin Tetras, which will stay apart or sometimes merge for a short time, making an amazing display.

– Tank Decoration

Dark sand or gravel makes an ideal substrate for any tetra tank.

Since the species spends a large portion of its time in flooded forestland, Bloodfin Tetras do best in tanks with either natural or artificial plants. These simulate the weeds so prevalent in their natural environments. A good planning strategy is to place vegetation heavily on the sides and back, leaving the central portion of the aquarium free for them to swim about.

Driftwood, bogwood, or similar structure can be added to mimic their natural environment.

They will appreciate having vegetation in which to rest, nibble on plankton, and breed. Providing dim light or blacklight to imitate the dark water conditions of their river environments cues the Cardinal Tetra to shine their most vivid colors.

If you want healthy, living plants, consider adding brighter lights on day/night timers. This cycle is important for any living plants you may have in the aquarium.

While Bloodfin Tetras are tolerant of a broad range of water conditions, dirty tanks and water can lead to sickness and the loss of your fish.

– Common Diseases

Bloodfin tetra careBloodfin Tetras are susceptible to a variety of naturally occurring and introduced illnesses. One of the most common illnesses is neon tetra disease.

Neon tetra disease is a very common ailment in tetra species. Named after the first species it was identified in, neon tetra disease is a parasitic infection that first cripples, then kills the fish. It can spread rapidly through tetra and similar species.

Neon tetra disease is caused by a parasite called Pleistophora hyphessobryconis. The parasite enters fish through the consumption of infected live or dead foods. Infestations can occur in aquariums when infected fish are inadvertently added to healthy stocks.

The parasite essentially consumes the host fish from the inside out and spreads quickly and is not treatable.

At the first sign of infection, you should remove diseased and dead fish from the aquarium. Indications you have something wrong with your Bloodfin Tetra include restlessness, significant loss of coloration, lumps on the body, and difficulty swimming.

In more advanced cases, fishes will display crooked bodies, bloating, and visible fin rot. If you lose a tank of fish to the disease, it is a very good idea to empty the tank, thoroughly clean, and start a new display.

The only way to prevent the introduction of neon tetra disease to an aquarium is to quarantine any new additions for up to two weeks before introducing them to the tank.  Try to purchase fish in person and visually select healthy specimens from a reseller who will guarantee their quality. If you purchase aquarium fish online, be sure the reseller will guarantee their fish for at least 30 days.

– Tank Mates

Bloodfin Tetras can be great neighbors with many kinds of similarly gentle Amazonian river species. Its only predilection is being an occasional fin nipper to slow-moving species.

Here are some great tank mate choices:

Dwarf Gourami: The Dwarf Gourami is a small, colorful member of the gourami species. These fish are peaceful schoolers and tend toward orange and red hues. Keep them in schools of 10 or more.

Pearl Gourami: The Pearl Gourami is covered with white, pearl-like markings. They are of similar temperaments and like the same types of vegetative habitats. They are an ideal choice, especially when you are kitting out an aquarium of over 30 gallons. Pearl Gourami does best in groups of six or so balanced heavily toward female fish.

Silver Dollars: The Silver Dollar is a species native to South America that can do well with Uaru. They are mostly peaceful, preferring the company of their species. They tend to leave other fish alone if they cannot fit them in their mouths.

Cyprinids: This family of fish contains most carp species. Its smaller members tend to live in the bottom layer of tanks and are omnivores. They mix well with other species as long as you do not overcrowd the tank.

Rosy Tetra: The Rosy Tetra, as well as many other species of Tetra, thrive in the same water conditions. They are peaceful, although may engage in fin nipping when stressed or in overcrowded tanks.

Guppy: There are many varieties of guppy that make great tank mates. What they all have in common is that they are peaceful fish that are not too small and get along well with any fish that will not eat them. Some of the more ornamental varieties add splashes of color to your community tank.

Bristlenose Pleco Variants : A few different color variants will keep well together and may result in interesting-looking varieties through breeding.

Corydoras: Like Plecos, Corydoras are a variety of bottom-feeding catfish commonly placed in tropical freshwater aquariums. They grow up to 4 inches in size and are peaceful omnivores.

Cardinal Tetra: Cardinal Tetras make great neighbors with many kinds of similarly gentle species. A small school of Cardinal Tetras adds beauty to any aquarium and does not create any type of significant bioload to the tank. Always a great choice. Add them in groups of 10.

Neon Tetra: Another great tank mate choice. Adding them in groups of 10, same as Cardinal Tetra, per 20 gallons of tank will give you an ever-moving, shimmering display.

Green Neon Tetra: If you want to keep a brightly colored aquarium, the Green Neon Tetra is another tank mate to consider. Similar in size and appearance to the Neon Tetra, the Green Neon Tetra, as its name implies, has a beautiful streak of neon green along its sides.

Here are some species best avoided as tank mates:

Kissing Gourami: This species of Gourami is a popular aquarium fish because of the kissing motions it uses to both feed and fight. It grows quite a bit larger than the Honey Gourami, up to 12 inches in length, and while quite beautiful, it can be aggressive to smaller fish in all levels of the aquarium.

Paradise Gourami: The Paradise Gourami is a beautifully striped and colored member of the Gourami family that is known both for its appearance and aggressive behavior. They will often fight other fish to the death and should not be placed in aquariums with peaceful fish such as Bristlenose Pleco.

Cichlids: There are many members of the cichlid species, but most of them are too aggressive to do well with tetras. Trying to cohabitate them will lead to bullying and fighting at the least.

Oscars: Members of the Oscar family tend to grow too large, too quickly, and have belligerent attitudes. Small Oscars will badger them, and large Oscars will eat them.

– Diet

The easiest aspect of caring for Bloodfin Tetras is feeding them. They are omnivorous and will accept almost anything offered.

Usually, they do just fine on commercially made tetra flake food or pellets. But they also like meaty protein foods, some of which may need to be chopped to a size small enough to fit in their mouths. Good meal choices include:

  • Bloodworms
  • Brine shrimp
  • Daphnia
  • Tubifex

Give them food once a day in the morning or evening. Try to limit how much food is put into the tank so that the actual feeding takes no more than three or four minutes. This prevents overeating, which can lead to other illnesses. You can tell your Bloodfin Tetra are getting too much feed if their stomachs start to appear bulged.

Limiting feeding time also prevents excess food from falling to the bottom of the tank and rotting. This can introduce bacteria and other potential illnesses that can wipe out an entire tank in a few days.


The Bloodfin Tetra is easy enough to breed that they are a great introductory species to learn about the process.

Breeding them is quite easy and is best conducted in a separate breeding tank that has been set up to match the overall conditions of their home tank, including vegetation. Make sure you have some anchored plants and open space. This aquarium should have a cover, or you might lose a few fish.

To get your fish into the breeding mode, keep light levels low and provide plenty of small-sized high-protein foods. When they are ready, the fish will naturally pair off, and the female will lay eggs.

Sometimes, the female fish will leap from the water while laying eggs. This is normal behavior. You might notice her jumping out of the water. This is normal.

More often the female will lay eggs in or on plants. Once the eggs have been laid, return the adult fish to their home tanks so that they do not eat their eggs.

If you get a successful breeding pair, they can lay as many as 500 eggs. If they hatch, you will have a great quantity of Bloodfin Tetra to keep, trade, or sell.

It only takes a few days for the fry to emerge. Once swimming they will consume their egg sacs first. Then you should provide infusoria or powdered fry food until they are big enough to consume baby brine shrimp.


  • Bloodfin tetra dietBloodfin Tetras are among the most colorful tetras.
  • Controlling water conditions is key to the successful long-term care of the species.
  • The best way to display Bloodfin Tetra is in a dimly lit aquarium with plenty of perimeter plants and vegetation.
  • Bloodfin Tetras are schooling fish. They make a vivid, colorful display.
  • Small, peaceful fish from the same river systems make ideal tank mates for Bloodfin Tetra.
  • Quarantine new tank mates for at least two weeks before introduction to ensure they do not carry neon tetra disease into your aquarium.
  • Ill or dead fish should be removed from the aquarium quickly.
  • Bloodfin Tetras are quite easily bred. It is best to do so in a separate breeding tank.
  • Bloodfin Tetras are easy to feed. They prefer meaty, finely chopped foods or commercial tetra flakes and pellets.

Aquarium keepers of all experience levels have Bloodfin Tetra displays for the beauty and color it brings into their homes. Whether you are new to the hobby or looking just for something fun, building out a South American Rainforest tank with Bloodfin Tetra and tank mates will provide a visually pleasing and rewarding keeper experience.

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