If you’re looking to start a freshwater aquarium, you might want to consider something a little different from the typical neon tetra. Bloodfin tetras are just as hardy and bring their own type of beauty to the tank with their large striking silver bodies and vibrant red fins. These fish are especially interesting due to their ability to be kept in a coldwater aquarium under certain conditions.
Keep reading to find out everything you need to know about bloodfin tetra care and keeping these freshwater fish in your own aquarium!
Aphyocharax anisitsi is commonly known as the bloodfin tetra. They are sometimes confused with the glass bloodfin tetra (Prionobrama filigera) though their scientific name categorizes them into a completely different genus from bloodfins, which we will discuss later.
The bloodfin tetra comes from the freshwater Paraná River basin that runs through Brazil, Paraguay, and Argentina. These waterways are usually shaded by an overhead canopy or other vegetation and filled with a variety of aquatic plants. The water may be murky from decomposing organic materials.
The bloodfin tetra looks like a couple of other species and can be initially difficult to correctly identify. These are some of the larger tetras available and can reach an adult size of 2-2.5 inches (5-6 cm). They have a silver body that can give off tints of green under certain lights. What really makes this fish special, though, is its colorful fins.
The bloodfin tetra is named exactly for its bloodfins! They will have a deep orange-red on their ventral, anal, and caudal fins. This is one of the main ways to tell this species apart from the very similar Prionobrama filigera.
Prionobrama filigera. Also known as the glass bloodfin tetra, these freshwater fish look very similar to the bloodfin tetra, Aphyocharax anisitsi, at first glance. However, the glass bloodfin tetra is in a different scientific genus and comes from more towards the north of South America (Ecuador, Colombia, Peru, Bolivia, and Brazil). There is only one other species in the Prionobrama genus, but it is unlikely to come across it in the aquarium trade.
P. filigera can grow to about the same size as regular bloodfins, reaching a maximum length of 2.5 inches (6 cm). The easiest way to tell them apart from the bloodfin tetra (Aphyocharax anisitsi) is by looking at their fins; glass bloodfins will have no red coloring on their anal or ventral fins, and will only have a red caudal fin. Glass bloodfins will also have a more elongated body than regular bloodfins.
If you do happen to pick up a mixture of P. filigera and A. anisitsi, there is a chance that they won’t school together, which we’ll discuss later.
How do I tell my female bloodfin tetra apart from my male?
Females are usually plumper than stream-lined males. Males may also grow small hooks on their pelvic and anal fins. The two fish are especially easy to tell apart when preparing for spawning; males will intensify in color and females will get rounder from carrying eggs.
Bloodfin tetra tank requirements
Bloodfin tetras are a schooling fish that need enough space to the group and swim together. These fish will do best in a school of at least 6-8, with more being even better if space allows. Due to their schooling habits, a minimum tank size of 20 gallons (76 L) is recommended. Every additional bloodfin added should have at least another 3 gallons (11 L) for itself.
These fish prefer dim lighting, so a dark substrate and floating plants may help lessen the intensity in your tank; Indian almond leaves may also be used to stain the water with tannins and provide additional health benefits, which you can read about here. A backdrop of dense plants will also help your fish feel more at home, but just make sure to leave enough water space for your tetras to openly swim around the tank.
Some suggested low maintenance aquarium plants are Amazon swords (Echinodorus sp.), Java moss (Taxiphyllum barbieri), Java fern (Microsorum pteropus), and species of Anubias.
These fish will need a stable water temperature between 64-82° F (18-28° C), which is a lower range than your typical freshwater fish. The pH should be between 6-8 and the water should be relatively soft.
Do bloodfin tetras need a heater?
The bloodfin tetra is slightly unique in that some hobbyists have been able to keep these fish in an aquarium without a heater. Since they can survive lower ambient water temperatures, they will do well as long as the aquarium stays a reasonable temperature and the temperature swings are not too intense.
While we always recommend using a heater for tropical fish, if you have a house where the room temperature does not drop below 60-65° F (15.5-18° C), then your bloodfin tetras should be fine! Remember, always use a thermometer to document how water temperature changes throughout the day and as well as from one day to the next.
Bloodfin tetra tank mates
Bloodfin tetras are a schooling fish and get along in most community tank settings. The best tank mates for these fish are actually more of the same species; they will need to be kept with at least 6 or more other Aphyocharax anisitsi.
You should have no problems keeping your bloodfin tetra school with non-fish tank mates like aquarium plants and invertebrates that can’t easily be eaten.
What other fish can live with bloodfin tetras?
These peaceful fish are great for a community aquarium and can be kept with an assortment of tank mates! But if you’re planning to get other schooling fish, like other species of tetra, don’t expect your bloodfins to school with them. For the most part, species of fish like to school with the same species and won’t intermix to form one giant school. This is why it’s important to get enough bloodfin tetras so that they can form their own group!
Other good tank mates would be rainbowfish, rasboras, danios, cories, and other tetras that are a relative size. Larger and more aggressive tank mates should be avoided as the bloodfin tetra is not that big and can be easily eaten. The bloodfin tetra also has a reputation of nipping at fins, so long-finned fish like angelfish and guppies should be avoided.
If you need some more ideas for other shoaling species for your bloodfin tetra tank, here are 7 easy schooling aquarium fish:
Harlequin rasbora (Rasbora heteromorpha). These fish grow to about 2 inches (5 cm) and are a vibrant orange with a striking patch of black. They will need to be kept in groups of 6 or more and need at least 13 gallons (50 L) to themselves.
Cherry barb (Puntius titteya). These peaceful barbs grow to about 2 inches (5 cm) and are lose schoolers. They do best in groups of at least 8 and need a larger tank for their active swimming. A minimum aquarium size of 18 gallons (70 L) will keep a school, but a larger tank will let them thrive with other species.
Black skirt tetra (Gymnocorymbus ternetzi). If you’re more attracted to the less colorful species of tetra, then the black and silver black skirt tetra might fit your tank. These fish grow to about 2-3 inches (6-8 cm) and are active swimmers. They need to be kept in a school or at least 6 in a 20 gallon (75 L) tank.
Southern platyfish (Xiphophorus maculatus). One of the most iconic beginner freshwater fish is the platy. They come in an assortment of colors and are easy to breed. They grow to about 2 inches (5 cm) and need to be kept in at least a 20 gallon (75 L) tank. They will do best in a group of 6 or more with more females than males to prevent chasing.
Zebra danio (Danio rerio). If you’re looking to house your bloodfin Tetra (Aphyocharax anisitsi) in a coldwater aquarium, then the zebra danio may make a good tank mate. They are very active swimmers and will need at least a 20 gallon (75 L) long tank even though they only grow to about 3 inches (7.6 cm).
White cloud mountain minnow (Tanichthys albonubes). Another compatible coldwater species is the white cloud mountain minnow. These fish are a little smaller than danios, only reaching 1-2 inches (2.5-5 cm). They will need a school of at least 8 and should be housed in a minimum tank size of 15 gallons (57 L).
Glowlight tetra (Hemigrammus erythrozonus). An alternative to the popular neon tetra is the glowlight tetra. These fish grow to about 2 inches (5 cm), need to be kept in groups of at least 6, and in an aquarium that is at least 10 gallons (37.8 L).
Bloodfin tetra behavior
The bloodfin tetra can be a very tight schooler, which is very interesting to watch. These fish really move together as a whole and can be seen swimming throughout the entirety of the tank; for the most part, these fish will stay in the middle and upper water columns of your aquarium.
The bloodfin tetra is a very stream-lined fish that can and will easily jump out of the aquarium at any given moment. Make sure that you have some kind of aquarium hood or other tank cover that will prevent your fish from escaping!
If only one bloodfin tetra is kept by itself, the fish will likely become very stressed out by other fish in the tank as well as from being outcompeted for food. This can quickly lead to disease and death, which is why we never recommended getting only one fish from a schooling species.
Here you can see how closely these fish swim together in their school (also check out that beautiful aquascaping!).
Are bloodfin tetras aggressive?
These fish are usually very peaceful and not labeled as aggressive. However, they have been known to nip at long-finned fish. They are also pretty active swimmers and could stress out more docile fish and outcompete them for food.
Bloodfin tetra diet
These omnivorous fish will most likely eat anything you feed them, from flake food to live food to frozen food. Any fish flake food provided should be high in crude protein to keep your tetras healthy and vibrant. Live and frozen foods, such as bloodworms and brine shrimp, should also be regularly offered for variety and a balanced diet.
Live foods can be difficult to come across and get expensive over time, so some hobbyists have turned to culture their own bloodworms and brine shrimp! If you want to try your hand at culturing live food, check out our guide for raising brine shrimp here.
Remember that these fish have small mouths and some things could be difficult to eat if too big. Also, make sure that you are not giving more food than what your fish can eat in a couple of minutes; excess food will quickly lead to algae in your tank!
Breeding bloodfin tetras
Whether you want to naturally expand your bloodfin tetra school or want to try aquarium breeding for the first time, these tetras are pretty simple to breed. It is best to set up a separate breeding tank that you can move your tetras into. This aquarium should have several fine-leaved plants to help catch eggs; these eggs won’t necessarily stick to the plants like other species, and some may fall to the bottom of the tank or float to the top!
Lighting should be dimmed and minimal as the eggs and fry are very sensitive to intense lighting. The water should also be more acidic. A sponge filter will help keep the water clean without sucking up the eggs and fry.
Your pair is ready to be transferred from your main aquarium when the female bloodfin is plump with eggs and the male intensifies in color. Once moved to the breeding tank, your fish should spawn the next morning; be prepared, your female bloodfin tetra can lay several hundred eggs at once!
Once you notice eggs in the tank, immediately remove the parent fish. They will not hesitate to eat any eggs or fry they come across. The eggs should hatch over the next day and the fry should become free-swimming a few days after that. Provide infusoria until the fry grow larger and then start supplementing crushed fish food.
When they are able to hold their own, acclimate them back into your display tank or give them to another hobbyist.
The bloodfin tetra may not be the first tetra that you think of for your freshwater aquarium, but will definitely become one of your favorite fish! Their tight schooling behavior and vibrant fins make them an unusual addition without any added maintenance.
As long as you have a large enough tank and provide safety in numbers, then you should have your bloodfins for a couple of years!
If you have any questions about caring for these tetras or have experience with these freshwater fish in your own aquarium, don’t hesitate to leave a comment below!