Freshwater Fish

Red Tail Tetra – Aphyocharax anisitsi: Care Guide

In our opinion, Red Tail Tetras are one of the most underrated species in the aquarium industry. Due to many other popular Tetras, these freshwater fish do not get the attention they deserve.

In fact, we have been huge fans of these fish for the past several years. They are quite pretty, easy to care for and peaceful.

This guide will give you an overview of all aspects of Red Tail Tetra care. You’ll learn about your ideal water parameters, tank mates, how to set up your tanks, and even breeding tips!

Species Summary

Red Tail Tetras (Aphyocharax anisitsi) or Bloodfin Tetra is a visually striking freshwater fish that is fun to watch and easy to care for. They are part of the characin family and share many of the same characteristics as other Tetras.

These fish are endemic to the rivers of South America. They are most commonly found in the Parańa river basin. However, they have also been seen throughout the Amazon, in eastern Peru and Colombia.

Today, you’re more likely to see these fish as part of a colorful community tank. Red Tail Tetras do well in large groups and get along with most peaceful fish. No matter how large your community tank is, these fish are sure to be the stars of the show.

Life expectancy

The typical lifespan of Red Tail Tetras is around 5 to 8 years in captivity. This is on par with many other popular tetra species.

Of course, there are no guarantees. Despite their hardiness, these fish can be sensitive to poor water conditions. They need a well-maintained habitat and plenty of high-quality food to really thrive. Otherwise, its lifespan could be significantly reduced due to illness or injury.


While Red Tail Tetras may not have the flowing fins or unique body shape like other aquarium fish, they are certainly quite beautiful in their own right. These are smaller fish that take the form of a torpedo. They are thicker towards the head and midsection. However, its shape tapers to meet its sizeable tail fin.

The main color of the fish is silver. The scales take on a somewhat iridescent finish. As a result, you may notice blue-green flashes when the light bounces off your body. The silver color covers most of its mass.

The only thing about this fish is its fins! They are appropriately named for the bright red color that covers their dorsal, anal, adipose, and caudal fins. It offers a stark contrast to the rest of its body and makes the fish stand out in any setting.

Normally, red will cover most of the fins. The only part that is 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.

You will not find too many differences between men and women. Sometimes mature males will develop visible gill glands and some subtle hooks on the anal fins. However, this is not a guarantee.

The best way to determine the sex is to look at the red coloration. Males tend to be more vibrant than their female counterparts. Females also tend to be a bit plumper. This is especially true in the breeding season.


The size of an adult Red Tail Tetras is just over 2 inches long. Thanks to their small size, they are very handy and work well in small to medium sized tanks.

Author’s note: If these fish are born in poor condition, it is common for them to be a little smaller than normal. This is due to developmental issues that end up affecting their size.

Red Tail Tetras Care

For the most part, Red Tail Tetras care is fairly easy. This species is hardy and can adapt to a wide range of environments, which is a perfect trait for a community tank. Furthermore, they are relatively peaceful and rarely cause harm to others.

Of course, these fish still need proper care if you want them to be healthy. To reach their full potential, Red Tail Tetras really do need carefully monitored environments. Providing them with everything they need will ensure that they reach their full size while living a long and happy life.

tank size

Red Tail Tetras are schools of fish. They do better in larger groups. As such, don’t expect to see much success keeping a fish alone in a small tank.

At a minimum, we recommend starting with a 20-gallon tank size. A tank of that size is adequate for 5 to 7 fish. Of course, the bigger the better.

Author’s Note: If you plan to house different species with your Red Tail Tetras or have a larger school, you should significantly increase the size of your tank.

water parameters

The best thing about Red Tail Tetras is that they are not particularly fussy when it comes to water parameters. They fit well and won’t have too much trouble with slight fluctuations.

That said, you still need to stick to a general range of water parameters. Like any fish, Red Tail Tetras do best in waters that are similar to their natural habitat.

This species comes from bodies of water in South America. They prefer things to be on the warmer side (although they can also survive in cooler tanks) with a relatively neutral pH balance. Here are some parameters to follow:

  • Water temperature: 64°F to 82°F (around 70 degrees is preferred)
  • pH levels: 6.0 to 8.0
  • Water hardness: 2 to 3 dGH

As long as you stay within these ranges, your fish should have no problem staying healthy. However, it is important to constantly test these levels to ensure they are stable.

Preparing your tank

This is where you can really get creative.

Red Tail Tetras need a lush tank filled with natural décor (after all, they come from the rivers of South America). The goal when planning your tank should be to replicate that environment as closely as possible.

You can start with a dark sand substrate on the bottom. The dark color is reminiscent of river beds, which are often covered with dead plant matter. Red Tail Tetras don’t spend a lot of time at the bottom of the tank, but having that base doesn’t hurt.

Now, use live plants to decorate the tank. Red Tail Tetras need plants for a couple of different reasons.

First, they offer shelter. These fish can get nervous at times and will need places to hide.

Second, it helps block out some light. Those South American rivers that they come from are often full of vegetation. In addition, the banks are lined with trees that block the sun.

You can choose between floating aquarium plants and tall plants. Try options like Java Moss, Broad-leaved Anubias, and Narrow-leaved Anacharis.

When adding plants, be sure to leave enough room for them to swim in the center of the tank. Arrange vegetation around the perimeter so that nothing prevents fish from swimming freely.

In addition to plants, consider using some artificial hiding places. You can use plastic caves, real rocks, or even driftwood.

As for equipment, your standard canister filter will work just fine. Just make sure it’s powerful enough to run the tank efficiently. Red Tail Tetras don’t really need a heater in the tank if the water is kept above room temperature year-round. Light can always warm things up when needed.

Author’s Note: Don’t forget a sturdy lid! Red Tail Tetras are known for jumping on the surface of the water. This tends to happen even more when spawning, so you need that lid to make sure they don’t jump out.

disease potential

As we mentioned earlier, Red Tail Tetras are quite hardy. Despite their small size, they are hardy and relatively healthy. The only time you need to worry is when water conditions take a nosedive.

Like any other species of fish, Red Tail Tetras are sensitive to extreme changes in the water. Rapid fluctuations in temperature or high levels of ammonia in the water can affect your health.

They will become stressed, increasing their risk of several common fish diseases. This includes bacterial infections, fungal problems, and even parasitic infections. The most common ailment you will likely have to deal with is Ich, which can be fatal if left untreated.

Fortunately, you can easily treat the condition with some over-the-counter medications. Just be sure to quarantine your infected fish, as Ich is highly contagious.

The best way to avoid illness altogether is to stay on top of water conditions. Check parameters regularly and do water changes every week or two.

Food and Diet

In the wild, Red Tail Tetras often eat insect larvae and plant matter. They are omnivores, so you shouldn’t have a problem finding something they like. For the most part, you can stick with commercial flakes or granules.

However, we always recommend supplementing dry foods with high-protein snacks. Brine shrimp, bloodworms, tubifex worms, and daphnia are all good high-protein choices.

Only feed these fish as much food as they can eat in about 2 minutes. They have small stomachs and overeating is a very real risk.

They should be fed twice a day, but make sure the meals are small.

behavior and temperament

Red Tail Tetras are active swimmers. You will see them hanging around in groups throughout the day. They usually only occupy the top half of the aquarium.

Aggression is not a big problem. They are generally quite peaceful and will get along with other peaceful species of fish.

However, you may notice a few small signs of aggression here and there, depending on the situation. They will fight within their group from time to time. Sometimes some larger fish bite smaller ones. You may notice Red Tail Tetras nibbling on others around feeding time.

Usually this isn’t a big deal, but keep an eye on them just to be sure. If it becomes an ongoing problem, you may want to consider getting rid of the offender to make sure everyone stays healthy.

Red Tail Tetras have been known to bite the fins of some other fish as well. They are attracted to the flowing fins of guppies and angelfish, so you may not want to keep those types of fish in the same tank.

Red Tail Tetras Tank Mates

Red Tail Tetras do best in groups. We recommend a group of 5 to 7 fish. If you have space, feel free to add more! A larger group can reduce the chances of in-fighting and will help each specimen feel more comfortable in the tank.

These fish do well with other fish species of similar size. Other types of tetras are great. In general, try to keep the fish a similar size.

Avoid all large and aggressive fish. With their small size and bright red fins, they can quickly become targets.

Below are some good Red Tail Tetras tank mates that can live in peace with this species:

  • neon tetra
  • cardinal tetra
  • cory catfish
  • neon green tetra
  • Pacific Shrimp (we like the Ghost and Amano)
  • Any freshwater aquarium snails
  • Ember Tetra
  • Gentle Plecos (try Bristlenose or Rubber Lip)
  • Bottom Dwelling Catfish (Pictus and Bumblebee are great)

Author’s Note: There are many other Red Tail Tetras tankmates you can consider. This list should only serve as a starting point. As long as the species is similar in size and peaceful, they are probably (behaviorally) compatible.


The reproduction process of Red Tail Tetras is quite simple. We recommend installing a separate breeding tank. Fill it with plants and wide open space.

To trigger the process, you can keep light levels low and provide plenty of high-protein foods. When they are ready, the fish will naturally pair up and the female will lay eggs.

You may notice her jumping out of the water. This is normal. These fish often jump above the surface of the water and let the eggs sink into bottom tanks. Sometimes they are a bit more organized and choose broad-leaved plants to lay eggs.

Either way, it is important to remove adult fish after spawning. They do not show any parental behavior and will try to eat the eggs. In total, the females can lay between 300 and 500 eggs!

They will hatch in a few days. The fry will consume the egg sac first. After that, you need to provide infusoria and powdered fried foods until they are big enough to consume brine shrimp.

What are you waiting for?

Now that you are familiar with the care of Red Tail Tetras and all the reasons why they are such a great freshwater species, you should really consider buying some for yourself.

These fish are a joy to own and they really are fun from start to finish. They are relatively low maintenance, beautiful, and fun to look at.

We have heard from many owners over the years who have nothing but great things to say about this species. Maybe you should join their club!

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