Bloodfin Tetra
The bloodfin tetra (Aphyocharax anisitsi) is a small, lively freshwater fish from South America with a silvery body and bright red fins. It is a hardy, active schooling fish, which makes it a great choice for beginner aquarium keepers.
Scientific Classification & Quick Facts
| Common name | Bloodfin tetra |
| Scientific name | Aphyocharax anisitsi |
| Kingdom | Animalia |
| Phylum | Chordata |
| Order | Characiformes |
| Family | Characidae |
| Genus | Aphyocharax |
| Conservation status | Least Concern |
| Type | Small freshwater tetra |
| Diet | Omnivore: worms, crustaceans, insects, plants |
| Habitat | Subtropical rivers |
| Native range | Rio Parana basin, South America |
| Size | Up to about 5.5 cm (2.25 in) |
| Lifespan | 5-8 years, up to 10 with care |
| Colours | Silver body with blood-red fins |
Habitat and Range
Bloodfin tetras come from the Paraná River basin in South America, which flows through Brazil, Paraguay and Argentina before reaching the Atlantic Ocean. They live in streams, rivers and ponds, usually in the middle and upper layers of the water.
Because their home is subtropical rather than truly tropical, bloodfin tetras can cope with cooler water than many other tetras.
What Bloodfin Tetras Look Like
Bloodfin tetras are slim fish that grow to about 5.5 cm (2.2 in) long. Their bodies are silvery, sometimes with a slight blue or green shine. Their fins, especially the tail, back and bottom fins, are bright blood-red, which gives them their name.
Males are usually slimmer and more colorful than females and have tiny hooks on their anal fin. With good care, bloodfin tetras often live for five years or more, which is long for such a small fish.
Behavior
Bloodfins are fast, peaceful fish that love to swim in groups. In the aquarium, keep at least six of them together, and more is even better. In a group they feel safe, show brighter colors and chase each other playfully. Kept alone or in pairs, they can become stressed and shy.
They get along well with other peaceful fish of similar size, such as other tetras, rasboras and corydoras catfish. Avoid tankmates big enough to eat them, and slow fish with long fins, which bloodfins sometimes nip.
Keeping Bloodfin Tetras at Home
Tank Setup
Bloodfin tetras are strong swimmers, so give them plenty of room to move. A tank at least 60 cm (24 in) long, holding about 20 gallons, is a good size for a small school. Always use a tight-fitting lid, because these tetras are good jumpers.
Try to copy their natural home with plenty of plants around the edges, open space in the middle for swimming, and dark gravel or sand, which makes their red fins stand out. If you are new to live plants, try hardy ones such as Java fern, which grows well under ordinary aquarium lighting. Live plants also use up nutrients that would otherwise feed algae.
Water Conditions
Bloodfin tetras are not fussy, but like all fish they need clean water. Use a good filter and change about a quarter of the water every week or two. Suitable conditions are:
- Temperature: about 18-28°C (64-82°F)
- pH: about 6.0-8.0
- Soft to moderately hard water
Because they tolerate cooler water, they can live in an unheated tank in a warm room. Even so, a heater helps keep the temperature steady, which is important for fish health.
Feeding
In the wild, bloodfin tetras eat small worms, crustaceans and insects, along with some plant matter. In the aquarium, they happily eat good-quality flake food as their main diet. Give them variety with frozen or live foods such as bloodworms, brine shrimp and daphnia a few times a week. Feed only as much as they can eat in two or three minutes.
Breeding
Bloodfin tetras breed quite easily, even in home aquariums. They are egg scatterers: the female releases eggs among fine-leaved plants near the surface, and the male fertilizes them. A female can lay a few hundred eggs at a time. The eggs are not sticky, so they fall down among the plants or onto the bottom.
Adults will eat their own eggs, so breeders use a separate breeding tank with a mesh or a layer of marbles on the bottom so the eggs fall out of reach. The adults are removed after spawning. The eggs hatch in about a day or two, and the tiny fry are first fed on very small foods such as infusoria and then baby brine shrimp.
Bloodfin tetra FAQs
Why is it called a bloodfin tetra?
It is named for its blood-red tail, anal, dorsal and adipose fins. The rest of its body is silver.
How big do bloodfin tetras get?
They stay small, usually under 2 and a quarter inches (5.5 cm) long.
How long do bloodfin tetras live?
Bloodfin tetras normally live 5 to 8 years, and up to 10 years when well cared for.
What do bloodfin tetras eat?
They are omnivores. In the wild they eat worms, crustaceans and insects, and in an aquarium they enjoy flakes, frozen or live foods and some plant foods.
Do bloodfin tetras jump?
Yes, they are expert jumpers, so their tank needs a firm lid. They are also strong swimmers, so a tank at least 20 inches long is best.
Randi Jones is the owner and founder of the Nature Gift Store, an online retailer specializing in nature-themed gifts, educational science projects, live animal nature kits and real butterfly artwork. A biology graduate who fell in love with insects, she founded the company in 2001 to make active learning about nature fun, accessible and engaging for children and adults. Her store offers real butterfly frames, home and garden decor and educational live animal kits, including ant farms, worm farms, tadpoles, ladybugs and hermit crabs, and she runs a bug museum in Washington featuring live animals like Eddie the Iguana alongside other reptiles and insects.
