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Bloodfin Tetra – Aphyocharax anisitsi

Bloodfin Tetra

Tetras are amongst the most popular aquarium fishes. There are probably more than 150 distinct species of tetra from which the aquarist may choose and this includes a large number of visually stunning fishes that are bound to enhance any home aquarium.

Is the Bloodfin Tetra a good community fish? The Bloodfin Tetra should be considered to be an excellent community fish and gets on with most species. It is known to be something of a fin-nipper so avoid keeping it with elaborately-finned species (Guppies, Angel Fish, male Bettas, etc.). 

Key Facts

CategoryKey Facts
Common name(s)Bloodfin Tetra – also known as:
Argentinian Tetra
Red-finned Tetra
True Bloodfin
Glass Bloodfin
Scientific nameAphyocharax anisitsi
Originate fromRio Parana and Argentina as well as Brazil, Paraguay and Uruguay in South America
Care requiredEasy to care for and hugely popular
TemperamentPlacid, shoaling fish
Colour & FormSilver, streamlined body with red dorsal, adipose, caudal, anal and pelfic fins. Adult male has hook on anal fin. Adult female is fuller-bodied.
LifespanUp to 10 years
Adult size2.5 inches
DietOmnivorous – eat aquatic insect larvae in nature
Aquarium size24 inches in length or greater
Compatible withMost other Tetras, Barbs, Danios and other livebearers, dwarf cichlids, smaller Gouramis, catfish and loaches
Avoid keeping withLarge and/or aggressive species and long-finned species including Guppies, Angel Fish and male Bettas
BreedingEasy if you put the fish in the right environment.
Water temp65 to 82 Fahrenheit
Water pH6.0 to 8.0
Water hardness (dGH or dH)Up to 25 dGH

Origins of the Bloodfin Tetra

Tetras, as a “family” of fishes belonging to the biological family Characidae are found in nature in Africa, Central America and South America.

The Bloodfin Tetra originates from the Rio Parana and Argentina as well as Brazil, Paraguay and Uruguay in South America. The vast majority of Bloodfin Tetras available to aquarists are captive-bred. 

Characteristics of the Bloodfin Tetra

As you can see, the Bloodfin Tetra is an elegant and streamlined fish which will grow to up to 2.5 inches in the aquarium and live for around eight to ten years. 

The Bloodfin Tetra is an active swimmer, always on the move. The Bloodfin Tetra has a silver, streamlined body. The dorsal, caudal anal, pelvic and adipose fins can be blood red in colour. The adult male may have a hook on its anal fin whilst the female may have a fuller body and, once gravid (carrying eggs) will become even more rounded and, at that stage, is even more easily distinguished from the male.

The Bloodfin Tetra tends to inhabit the middle to the top of the aquarium. That said, it is a vigorous fish when breeding and will readily traverse the entire aquarium.

The Bloodfin Tetra is, by nature, a shoaling fish and it is generally recommended to purchase six or more fish, as their nature is to swim together as a shoal and they will tend to thrive much better as a shoal. Bloodfin Tetras do have a reputation for being fin-nippers so it would be best not putting them together with long-finned species such as Guppies, Angel Fish, male Bettas or other elaborately-finned species.

Whilst it is typical to keep at least six Tetras in an aquarium it is generally recommended to keep ten or more Bloodfin Tetras, as they tend to thrive better. It is also suggested that if the temperature of the water is higher in the given range then the colouring of the red fins is more striking. That said, water at a higher temperature tends to shorten the lifespan.

Bloodfin Tetras prefer a shaded tank so consider including floating leaves and/or allowing vegetation to grow so that it floats on the surface of the water to provide shade.

It is generally advised that the minimum tank size for Bloodfin Tetras should be one of 24 inches in length or more due to the active nature of the species, which will enable a small shoal to move around freely. The tank should be well-planted but with clear areas where the fish can swim freely. The water should have gentle movement.

Bloodfin Tetras prefer fairly neutral water with a pH of 6.0 to 8.0, cooler than many tropical species; from 65 up to around 82 Fahrenheit and up to 25 dGH.

It is somewhat difficult to determine with certainty the sex of most Tetras. It is, however, easier to determine the sex of Bloodfin Tetras since the adult male has a hook on his anal fin and, once a female is gravid (carrying eggs), as her belly becomes much more rounded.

The general rule for Tetras is that by keeping six or more of the same species in an aquarium they will be fully aware of which is male and which is female and they will act accordingly.

Most (but not all) Tetras have an additional fin which identifies them as being Tetras and the Bloodfin Tetra is no exception. If you look between the dorsal fin and the caudal (tail) fin of the Bloodfin Tetra you will observe a tiny, additional fin, known as the adipose fin. The purpose of this fin is not fully understood but, if it is present on a fish then you can be pretty certain that the fish is a Tetra.

Tetra comes from the Greek word “Tetragonopterus” which means square-finned and appears to relate to the four fins on vertical plane of the fish (dorsal, adipose, caudal and anal fins) which span the central line of the fish (when viewed from above or below, front or rear) and are not present as a pair (e.g. the pectoral fins).

Bloodfin Tetra – Video

How do Bloodfin Tetras breed?

Tetras, in general, will scatter eggs by laying them over fine plants such as Cabomba, Fontanalis or Java Moss.

Bloodfin Tetras are noted to leap above the water surface during breeding so it is advised that the tank should be covered to mitigate the risk of losing fish.

As the female Bloodfin Tetra becomes ripe with eggs, the difference between the sexes becomes even more evident. If you plan to attempt specifically to breed Bloodfin Tetras then it is recommended that you have a breeding tank prepared. Such a tank can be empty but you may wish to include a mesh or grid under which the fertilized eggs will fall. The eggs of the Bloodfin Tetra are not adhesive.

That said, Bloodfin Tetras will breed in a community tank and, if the tank is well planted, it is likely that at least a few fry may survive to reach adulthood.

I have observed Bloodfin Tetras breeding readily and vigorously in quite neutral water. 

The female will swim around the tank and, if you include two males then they will encourage her to lay her eggs by bumping into her. She will lay her eggs which will immediately be fertilized by the male(s) and will fall to the bottom of the tank (preferably through the mesh or trap). Once spawning is complete, remove the adults, as they are likely to consume the eggs, given the chance, and take no further parental responsibility.

Breeding tank for Bloodfin Tetras

You should prepare a tank of around 20 gallons in size with mature water. The water should be at a pH of around 6.8 to 6.8, a dGH of 18 and, ideally around 78 degrees Fahrenheit with a low level of light.

You may wish to introduce mosquito larvae or bloodworm as an inducement to reproduction.

The female will swim amongst the plants, laying her eggs whilst the male will swim alongside or behind her and fertilize the eggs as they are laid. Typically, the female can lay between 300 and 500 eggs, which will sink to the bottom of the tank.

Once the female has scattered her eggs and the male has fertilized at least some of them then the adults should be removed carefully from the breeding tank because they will have nothing more to do with the eggs but they may simply eat them.

Keep the lights off and the tank dark because Tetra eggs and fry are particularly sensitive to the light.

The eggs will hatch typically in a day or two depending on tank temperature and conditions and the fry will become free-swimming after around one week after hatching. Keep the tank unlit for the first week or so then gradually increase the lighting.

The newly hatched fry will firstly feed from their yolk sac but, once free-swimming, can be fed infusoria (particularly rotifers) and will also thrive on egg yolk during the first two to four weeks. It is worth mentioning that immediately after hatching, fry may seem quite vigorous but will soon go into a resting state before they become free-swimming so please don’t mistake this initial stage as being free-swimming.

After around four days or so add baby brine shrimp. Once the fry are sufficient in size not to be treated as a snack then they can be introduced into the community tank where they will join the existing shoal. Before moving the adolescent fish into the community tank ensure that you have balanced the water temperatures to mitigate the risk of White Spot or other diseases being triggered.

Should your Bloodfin Tetras have a special diet for breeding?

Adult Bloodfin Tetras don’t need any particular inducement to breed. That said, it has been suggested that adding mosquito larva may encourage them, presumably because the addition of a new food may “fool” the fish into thinking that it is breeding time. 

Mike Wheeler

I started keeping freshwater tropical fish in 1972 and it has been something of a passion ever since. In this website, my aim is to build up an everyman's guide to help the everyday aquarist get the best from this inspiring and entertaining hobby.

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