Corydoras Catfish

3 Corydoras Catfish cleaning the algae off of a rock at the bottom of their aquarium

Are you looking for a new fish to add to your home aquarium? If so, you may want to consider the Corydoras Catfish. These small, peaceful fish are a great choice for new aquarium owners and can make a wonderful addition.

Corydoras Catfish are native to South America’s rivers and come in a variety of colors and patterns. They have an elongated body shape and can grow up to four inches in length. They are bottom dwellers, meaning they spend most of their time near the substrate of the aquarium.

When people think of Corydoras Catfish (also known as Cory Catfish), they think of an algae eater, but what you might not know is that Cory Catfish are also known for their beautiful colors.  Not only do they come in a variety of interesting colors, but they also have a number of beautiful patterns. These patterns tend to be thicker on their rear and thinner on their head.

They are small fish, and they’re one of the most popular catfish species on the market today. Cory Catfish are a very active species of catfish. They’re known for being non aggressive towards other fish. 

One of the best things about Cory Catfish is that they can get along with most tank mates. They’re particularly nice with other species of fish, and they won’t hurt smaller fish either. Corydoras catfish are very hardy and can survive in a wide range of temperatures.

Corydoras catfish are peaceful, friendly fish that are easy to care for. They are very attractive, and will make a nice addition to any aquarium. They are very easy to maintain, and only need minimal attention. 

Corydoras Catfish are a peaceful species that get along well with other fish. They prefer to be kept in groups of at least five. Keeping them in groups helps them feel secure and reduces their stress levels.

Corydoras Catfish are omnivores, meaning they will eat both plant and animal matter. They prefer a diet of small live or frozen foods such as brine shrimp, bloodworms, and daphnia. They also enjoy sinking pellets and flakes. It is important to provide them with a varied diet to ensure they get all the nutrients they need.

Overall, Corydoras Catfish are an excellent choice for first time pet owners. They are peaceful, active fish that get along well with other species. They require minimal care and can tolerate a wide range of water conditions. With the right diet and environment, they can make wonderful family pets.

They’re fairly affordable, costing $5 to $17 each.

Information about Corydoras Catfish

  • Average Length: 1 to 4 inches
  • Scale Colors: White, Green, Bronze, Black and Albino
  • Attention Needs: Low
  • Tolerance to Heat and Cold: Yes
  • Good Pet: Yes!
  • Safe with Children: Yes
  • Good with Other Cory Catfish: Yes
  • Good with Other fish species: Yes
  • Good for Less Experienced Pet Owners: Yes
  • Health Concerns: Red Blotch and Ich.
  • Average Life Span: 5 – 7 years

Physical Appearance of Cory Catfish

a close up of the front half of a Corydoras Catfish at the bottom of their aquarium

Just like Plecos, Corydoras Catfish also have an armored body with bony plates covering most of their body. Even their fins are heavily spined which acts as a defense mechanism to protect them from predators. Because of their armor, they are often called ‘armored catfish.’

Cories have dorsal fins that point upwards, making it look like a sail. Some may also have rounded dorsal fins. The tail fin is fork-shaped with different species having different length and height.

They have a short head with a ring around their eyes. Near their mouth, on the front of their face they have three pairs of barbels that look like whiskers. These barbels help them find food in the sand.

There are over 170 different species of Cories and the majority of them are still not named! With so many different species, Cories can have many different color variations and patterns.

For example, the Panda Cories have a white or orange body with black patches around their eyes and dorsal fins. Because of their black and white coloring, they were named Panda Cories. On the other hand, Peppered Corydoras Catfish have a bronze body with black patches all over their body.

Temperament of Cory Catfish

Just like other catfish, Cories are a bottom-dwelling species. While many think that the Cories are nocturnal, this isn’t the case. They may sometimes move around at night, but they’re mostly active during the day.

Cories are a shoaling fish which means that they like to stay in a group. They should be kept in a small group of 6 or more. Staying in a group helps them feel secure.

While they are curious fish, Cories will spend most of their time scavenging for food close to the bottom of their tank. Some people find it strange that they’ll spend time at the bottom staying still, but this is completely normal for them.

a Corydoras Catfish at the bottom of their aquarium near some aquatic plants

Corydoras Catfish are peaceful and non-aggressive. They will not attack other fish. If they feel threatened, Cories will swim away to a hiding spot or use plants to get away from the attacking fish. These qualities and more covered later make them a great choice for a community tank.

Best Habitat for Corydoras Catfish

Corydoras Catfish are hardy and easy to care for. Compared to other fish species they don’t need a very large tank. All that’s needed is to maintain good water conditions for them inside the tank.

While setting up their tank keep in mind that Cories are very sensitive to toxic compounds like ammonia, nitrite and nitrate. Make sure that the tank is cycled before introducing your fish to their new home. Cycling helps to promote the growth of beneficial bacteria that break down the toxic compounds into less toxic ones.

Tank size

Most species of Corydoras Catfish are small and will not grow more than 4 inches, a 10-gallon tank is enough for a Cory Catfish. Because these fish like to stay in a group, a 20 gallons tank is needed for a group of 6. If you plan on keeping other fish species with your Cories, then a larger tank will be needed.


Cory Catfish like the water temperature to be in the between 70° and 80°F. More important than establishing a perfect temperature, it is important to ensure that the temperature stays stable. Sudden fluctuations can stress your fish.

a Corydoras Catfish near some rocks at the bottom of their aquarium

Water Hardness and pH

Most Corydoras Catfish will need a pH level kept between 6 and 8 and water hardness between 5 and 10 dGH. Depending on the specific species this may slightly vary.


Cories do not have any specific lighting needs and will be fine with any type of lighting in their tank. At the same time, adding lights to your tank is important because living plants and other fish species will need the light to grow. LED lighting can be added because they are efficient and will light your tank without generating a lot of heat. Cory Catfish are hardy and will adapt to anything you decide to use.


Living plants should be added inside the tanks because Cory Catfish love them! They will like almost any kind of plant. For beginner fish tank owners Java Fern, Java Moss or Anubias Nana are a great choices because they are easy to plant and need minimum care.

Tank Conditions for Corydoras Catfish

Cories need a current and there should be a small current inside their tank. Air filters or air stones can be used to create a mild water current inside your tank.

a Corydoras Catfish cleaning rocks of the algae growing on them

For substrate avoid using gravel because it can seriously injure them. The sharp edges on gravel can cut their stomach and fins. A sand substrate is recommended because it won’t injure your Cories. Avoid using white sand because when tank waste settles on it, the waste will make the sand look dirty.

One important thing to note here is that It can be difficult to grow live plants in a tank with a sand substrate. Sand is not effective at absorbing nutrients that the plant needs. To make it easier to grow in sand you can add root tabs to your substrate.

Tank Maintenance

The water conditions like temperature, pH level, and dissolved organic compounds should be monitored daily. Make sure the water filters are running properly and are efficiently cleaning the water. A water testing kit should be used to regularly check the tank conditions.

Cories are scavengers and will feed on decaying plants or organic matter that will help keep the water clean. Many families have said the water conditions in their tanks improved after adding Cory Catfish.

Perform a 20% water change every week to ensure that the ammonia, nitrates and nitrite levels stay under control. Make sure you only add dechlorinated water to your tank after performing water changes.

Best Tank Mates for Corydoras Catfish

a Corydoras Catfish resting on some rocks at the bottom of their aquarium

Cories are timid and will not get aggressive even if threatened. Keeping peaceful fish species is recommended because it will help make them feel secure and keep them healthier.

A few great tank mates for Corydoras Catfish are:

Avoid keeping Cichlids and Barbs with Cories as they can become aggressive or nip your Cories.

Health Issues

While buying a Corydoras Catfish, check them carefully. A healthy fish will be active, bottom-dwelling, have undamaged fins, clear eyes and will have bright coloration on their skin.

Most diseases in fish are due to poor water quality and maintaining stable water conditions will ensure your fish is healthy.

a cory catfish with white spot disease

White Spot Disease (Ich)

Ich Disease, also known as Ichthyophthirius multifiliis or white spot disease, is a common parasitic disease that affects many species of freshwater fish. It’s caused by tiny parasites that attach themselves to the surface of a fish’s skin and gills and feed on them. These parasites appear on your fish as white spots on their body and fins, resulting in distress and discomfort.

The best way to prevent Ich Disease is to maintain a clean and healthy aquarium environment. This means ensuring that temperature, pH, hardness, and other levels remain within the correct range for the fish species being kept. Careful tank mate selection is also important; some fish are more susceptible to Ich than others. If a fish is already infected, quarantine them in a separate tank.

Red Blotch

Red Blotch is an infectious disease that affects many species of freshwater fish. It’s caused by a group of viruses known as the Iridoviridae family. The disease is associated with white to reddish spots or blotches on their body and fins of the affected fish. In severe cases, lesions can be deep and cover large parts of their body.

Red Blotch can have devastating effects on the fish’s health. The virus directly attacks their skin, causing it to become inflamed and irritated. This irritation can cause severe stress for the fish, which in turn leads to a weakened immune system and increased susceptibility to other infections and diseases. In some cases, Red Blotch can lead to death.

The disease is spread through direct contact between infected and healthy fish, as well as through contaminated water and equipment. It can also be introduced into new bodies of water via the introduction of infected fish, or on the body or fins of a wild fish that has been caught and released.

Feeding Cory Catfish

a pile of colorful fish flakes

Like other bottom-dwelling fish, the Corydoras Catfish are natural scavengers. They will always look for dead plants or uneaten food at the bottom of the tank to eat. They should also be fed with the other fish because waste materials should not be their only source of food. Cories are omnivores and need to be fed regular fish food to keep healthy.

They like to be fed algae flakes or algae wafers, pellets and bottom feeder tablets. Bloodworms can be given to them as an occasional treat. If you plan to breed any of your fish you should know that Cories tend to eat the eggs of other fish species.

They should be fed once a day and should be no more than what they can eat within 5 minutes.

Related Questions on Corydoras Catfish:

Are Corydoras Catfish Venomous?

Cories have sharp spines on their fins that do release a mildly toxic chemical when they feel stressed or threatened. The toxin is not fatal to humans. It will only produce a mild irritation or sting if the spine cuts your skin. If you have to handle the fish or move them out of the tank, be careful to not touch their spines.

Because they release this chemical when they feel threatened, it is not recommended to add the bag water used to transport them. Your new Cory may have released the toxin into the bag water while feeling stressed inside the transport bag. Adding this water could cause other fish in the tank to become sick.

Is it Normal for Corydoras Catfish to Come Up to the Surface?

Sometimes the Cories will rise to the surface of the tank to breathe in air. Many fish do this in the wild to breathe oxygen but in captivity, it could be a result of poor water quality. For Cories this behavior is normal and does not really mean there is insufficient oxygen in the water. There should be a concern only if they do this frequently. In this case, the water conditions need to be checked and corrective measures should be taken, if required.

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