Disk tetra Care Guide: Diet, Tank Mates, Diseases, Breeding & More

Updated: November 1, 2022

The disk tetra (also known as the black widow tetra) is a beautiful, but often overlooked, freshwater fish.

This species is perfect for beginner aquarists because they’re very hardy and easy to care for.

Disk tetras are also a good choice if you’re looking for a peaceful community fish that won’t bother your other fish.

But before you go out and buy a bunch of these fish, there are a few things you need to know about their care. In this guide, we’ll teach you everything you need to know about disk tetra care.

Species overview

The disk tetra (scientific name: Moenkhausia pittieri) is a freshwater fish that’s native to the Orinoco Basin in South America.

They are found in a wide variety of habitats but prefer slow-moving waters with plenty of vegetation. This could be in the form of floating plants, submerged plants, or even just a lot of leaf litter on the bottom of the river.

The diet of the disk tetra in the wild consists of mostly small insects and crustaceans. However, they are not opposed to eating the occasional plant matter as well.

In the aquarium trade, these fish are fairly popular due to their small size and peaceful nature. They are often kept in community tanks with other peaceful fish species.


Disk tetra

The first thing you’ll notice about this species is their disk-like shape. As their name suggests, these fish are very flat from top to bottom. This gives them a very wide and circular appearance when you look at them from the side.

Their bodies are a little less than twice as long as they are tall and they have a short snout. Disk tetras have small eyes that are close to the front of their head.

These little guys have dorsal and anal fins that are roughly the same size and shape. Both of these fins are large and begin almost halfway back on the body. The dorsal fin has a slight point at the end while the anal fin tapers off.

Their caudal and pectoral fins are both fairly large as well. The caudal fin is forked and the pectoral fins are fairly wide.

Disk tetras are very colorful fish. They have a silver base color that is adorned with black spots. These spots tend to be more prominent on the upper half of the fish. They also have a bright red or orange stripe that runs from their snout all the way back to the base of their tail.


The average lifespan of a disk tetra is 5 to 10 years. However, there are a number of factors that impact their life expectancy.

For starters, if these fish haven’t reproduced then their lifespan will usually be on the higher side of this range. That process can really take a toll on the fish.

The general level of care they receive obviously matters a great deal as well. Even though these are very hardy fish, they’ll obviously live longer in optimal conditions.


The average disk tetra size is about 2.5 inches when fully grown. However, these fish can reach up to 3 inches in length under the right conditions.


Tank Size

The minimum tank size for a school of six disk tetras is 20 gallons. If you want to keep more than six fish, you should add 2 to 4 gallons of water per additional fish.

Disk tetras are a schooling fish, which means they should be kept in groups of at least six fish. If you don’t have enough fish in your school, they will become stressed and may start to display aggressive behaviors.

Water Parameters

The disk tetra is a freshwater fish that is native to South America. They are found in the Paraguay-Parana basin.

The disk tetra is a peaceful fish that does well in a community tank. They are schooling fish and should be kept in groups of at least six.

The disk tetra is an easy fish to care for and does well in a variety of water conditions.

  • Water temperature: 70-80 degrees Fahrenheit
  • pH levels: 6.0-8.0
  • Water hardness: 2-12 dGH
  • Alkalinity Levels: 4-8 dKH

What To Put In Their Tank

When it comes to setting up an aquarium for disk tetras, there are a few things you’ll need to take into consideration.

The first is the size of the tank. These fish are relatively small, so they don’t need a lot of space to swim around. A 20-gallon tank is more than enough for a small group of these fish.

The second thing you need to think about is the substrate. These fish like to dig, so a soft substrate is a good choice. Sand or gravel should work fine.

The third thing to consider is the plants. Disk tetras are known to nibble on plants, so you’ll need to choose something that can withstand a little abuse. Hornwort, water wisteria, and Java moss are all good choices.

Finally, you’ll need to add some hiding places for these fish. Rocks, driftwood, and caves are all good choices. Just make sure there are plenty of places for these fish to hide.

Common Diseases

Disk tetras are a hardy and relatively disease-resistant fish. However, they are still susceptible to the same illnesses and diseases that can affect any other freshwater fish.

The most common disease that these fish experience is ich. This is a very contagious disease that is caused by a parasite. It’s most easily spread in tanks with poor water quality.

The most obvious symptom of ich is the presence of white spots on the body of your fish. These spots can range in size, but they’re usually pretty small.

If you notice any white spots on your fish, it’s important to act fast. Ich is a very serious disease and it can be fatal if left untreated.

The best way to prevent ich (and other diseases) is to maintain a clean and stable tank. This will create an environment that is less conducive to the spread of disease.

It’s also important to quarantine new fish before adding them to your tank. This will help to prevent the spread of disease if any of your new fish are sick.

Behavior & Temperament

The disk tetra is a shy fish that does best in a group of six or more. They are peaceful fish that get along with other peaceful fish. They are not known to be aggressive.

The disk tetra is a bottom-dweller and will spend most of its time near the bottom of the tank. They are known to be good jumpers, so make sure your tank has a lid.

The disk tetra is a timid fish and may be bullied by other fish. If you see your disk tetra being bullied, you may need to remove the aggressor from the tank.

The disk tetra is a omnivore and will eat most things. They are not picky eaters.

Tank Mates

The disk tetra is a schooling fish, which means it does best when kept in groups. A group of 5-10 is ideal, but you can get away with fewer if you have other schooling fish in the tank.

These fish are peaceful and can be kept with a wide variety of tank mates. They’re not aggressive and won’t bother other fish. In fact, they may even help keep the tank clean by eating algae.

Some compatible tank mates for disk tetras include:

  • Guppies
  • Mollies
  • Platies
  • Swordtails
  • Tetras
  • Rainbows
  • Danios



The Disk tetra is a relatively easy fish to breed in captivity. The first step is to identify the males and females. The males tend to have more coloration and are a bit larger than the females.

Once you have your group of fish, you will need to set up a breeding tank. The tank should be at least 10 gallons and should have soft, slightly acidic water. You can use a sponge filter to avoid harming the fry.

The next step is to add some plants to the tank. The plants will give the fry a place to hide and will help to keep the water quality high.

When the tank is set up, add the fish and let them acclimate. Once they are acclimated, you should start to see spawning. The female will lay her eggs on the plants and the male will fertilize them.

After the eggs are laid, you should remove the adults from the tank. The eggs will hatch in about 24 hours.

Once the fry have hatched, you can feed them live baby brine shrimp or crushed flake food. Be sure to feed them small amounts several times a day.

As the fry grow, you can gradually introduce them to larger foods. When they are large enough, you can move them to your main tank.


All in all, the Disk Tetra is a great fish for beginners and experienced fishkeepers alike. They’re not too difficult to care for and their unique appearance is sure to turn some heads.

If you’re looking for a fish that is a little bit different than the rest, the Disk Tetra is definitely worth considering!