Corydoras nanus: A Guide to the Little Cory Catfish

a school of corydoras nanus mini cory
Dr. Mollie Newton
Published by Dr. Mollie Newton PHD| Senior Editor
Last updated: June 21, 2024
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The Nanus cory cat, also called Corydoras nanus, is a **favorite** among freshwater aquarium fans. This little fish with its **bright colors** and **fun personality** brings excitement and magic to any tank. Aquarium lovers adore it for its **unique traits** and small size. Taking good care of them and keeping their tank in tip-top shape is key to keeping these charming pets happy and healthy.

Article Summary

  • Corydoras nanus, also known as the Nanus cory cat, is a popular freshwater aquarium fish known for its vibrant colors and playful nature.
  • These fish belong to the Callichthyidae family and are native to the Amazon River basin in South America.
  • They have a silvery to rose gold base color with two to three dark longitudinal stripes and distinctive yellow-tinged fins.

Species Overview

Corydoras nanus, also known as the Little Corydoras or Nanus Cory, belongs to the Callichthyidae family of armored catfishes. Its scientific name is Corydoras (lineage 5) nanus Nijssen & Isbrücker, 1967. The name “Cory” refers to a helmet, while “doras” means skin, and “nanus” signifies dwarf.

These fascinating little fish are native to the Amazon River basin in South America. They prefer to dwell at the bottom of their habitat and often form schools with other members of their species. Initially described based on specimens from Surinam-Brokopondo’s Surinam River system, the holotype measured a mere 23mm.

While Corydoras nanus is considered rare, there have been limited collections of these unique creatures. They can be found primarily in Suriname within the Maroni River basin and also in French Guiana’s Iracoubo River basin.

Nanus corydoras catfish displays a silvery to rose gold base color with two to three irregular dark longitudinal stripes along its body. Its fins are transparent with an irregular dark pattern. The fish typically has two white stripes running along its body with a blackish stripe between them, while all fins exhibit a yellow tinge.

Nanus cory cats reach approximately 45mm or 1.8″ SL (Standard Length). These fish have a relatively slow growth rate and can live for about 5-8 years up to a maximum of 10 years.

Habitat & Tank Conditions

Nanus corydoras catfish, also known as mini corys, are found in freshwater environments with moderate currents. They prefer shallow depths ranging from 20 to 50 cm and sandy to sandy-muddy bottoms. These little fish thrive in subdued lighting conditions.

Tank Size & Set Up

It is recommended to have a minimum tank size of 20 gallons for mini corys. This allows them enough room to swim and explore their surroundings. Make sure the tank has proper filtration to maintain water quality.

Water Parameters

Nanus corydoras catfish require specific water parameters for optimal health. Provide soft, slightly acidic water within the pH range of 6.0 – 8.0. The temperature should be kept between 22°C – 26°C (72°F – 79°F). Maintaining these parameters mimic their natural habitat and promote their well-being.

Substrate & Decor

To create a suitable substrate for mini corys, opt for smooth sand or round gravel that won’t harm their sensitive barbels while they scavenge for food.

Include hiding spots within the aquarium environment using lush vegetation such as plants, driftwood, and rocky caves. These shaded areas mimic their natural habitat and provide security for the fish.

Sand or smooth gravel substrate won’t harm their sensitive barbels.

Tankmates & Temperament

Corydoras nanus, also known as Nanus Cory cats, are small catfish species that bring a peaceful and social vibe to your planted aquarium. These delightful little fish thrive when kept in groups, so it’s best to have at least four individuals of their own species or mixed with other cory cat species.


One of the key benefits of keeping Corydoras nanus in groups is their social behavior. They are known to be peaceful towards both their own kind and other fish species, making them an excellent choice for community tanks. These sociable creatures enjoy exploring together and will often swim in a coordinated manner.

Compatible Tank Mates

When selecting tank mates for your nanus corydoras catfish, it’s important to choose fish that share similar water parameters and have a peaceful temperament. Here are some suggestions for compatible tank mates:

  • Tetras: Small schooling fish like Neon Tetras or Ember Tetras can create a vibrant display alongside the Nanus Cory.
  • Rasboras: Species like Harlequin Rasboras or Chili Rasboras make great companions due to their peaceful nature.
  • Danios: Zebra Danios or Pearl Danios can add some lively energy to the aquarium while coexisting harmoniously with the Nanus cory cat.

Tank Mates to Avoid

While Corydoras nanus are generally friendly, there are some species you should avoid pairing them with. Aggressive or fin-nipping fish may harm these small catfish. It’s best to steer clear of:

  • Cichlids: Larger aggressive cichlid species may see the Nanus Cory as potential prey.
  • Barbs: Some barb species can be nippy and may nip at the fins of these delicate catfish.
  • Betta Fish: Male Bettas, also known as Siamese Fighting Fish, have long flowing fins that may attract aggression from the Nanus Cory’s tank mates.

By selecting compatible tank mates and avoiding aggressive species, you can create a harmonious community aquarium environment that allows your nanus corydoras catfish to thrive.

Corydoras nanus Care

To ensure the well-being of your Corydoras nanus, here are some care recommendations to keep in mind.

Water Quality and Maintenance

Maintaining good water quality is crucial for the health of your Nanus cory cat. Regular water changes and monitoring ammonia levels are essential. These delicate fish have sensitive barbels, so it’s important to handle them with care during maintenance tasks.

Diet and Nutrition

In their natural habitat, Corydoras nanus consume small worms, crustaceans, insects, and decaying matter. To provide them with a balanced diet, offer high-quality sinking pellets, frozen or live foods.

While they scavenge the smooth gravel substrate for food, it’s also important to provide sinking foods specifically designed for bottom dwellers. They are good at keeping the substrate clean but should be offered supplemental foods to ensure proper nutrition.

Fish flake food
Offer a variety of high quality fish food to ensure proper nutrition.

Common Diseases & Prevention

Like any other fish species, Nanus cory cats can be susceptible to certain diseases. It’s important to take preventive measures to keep them healthy.

Maintain excellent water quality by regularly testing parameters such as pH and temperature. Quarantine new fish before introducing them into the main tank.

Avoid overcrowding the tank as it can lead to stress and increased disease susceptibility. Provide a well-balanced diet and avoid overfeeding.

Keep an eye out for signs of illness such as loss of appetite, abnormal swimming behavior or appearance changes.

By following these care recommendations and providing a suitable environment for your Nanus cory cat, you can help ensure their longevity and well-being in your aquarium.

Breeding the Corydoras nanus

Breeding the Nanus corydoras catfish can be an exciting and rewarding experience for fish enthusiasts. These small catfish, with males reaching around 4.5cm (1¾ inches) and females growing slightly larger at approximately 5.0cm (2 inches), require specific conditions to successfully reproduce.

Creating the right environment is crucial for breeding success. Provide plenty of hiding places in the tank, such as caves or dense vegetation, to mimic their natural habitat. Maintaining stable water parameters is essential, including 0 ppm Ammonia, 0 ppm Nitrite, and a Nitrate level of around 10 ppm.

To stimulate breeding behavior, consider conditioning your nanus corydoras catfish with live food and incorporating cold water changes. These measures can help simulate the rainy season triggers that these fish typically encounter in their natural habitat.

Recommended Tank Set Up

When setting up a tank for breeding Nanus cory cats, it’s important to replicate their natural environment as closely as possible. Here are some tips:

  • Maintain a temperature range between 22°C to 26°C (72°F to 79°F).
  • Provide soft substrate like sand or fine gravel.
  • Incorporate plants and decorations to create hiding spots.
  • Consider adding driftwood or other materials that release tannins into the water.

By recreating these conditions, you increase the likelihood of successful breeding.

Aquarium and Water Heater on a Table
Incorporate the right elements in your Nanus cory breeding tank to increase chances of success.

Breeding Process

Nanus cory cats exhibit interesting behaviors during courtship and egg-laying. The males will engage in elaborate courtship rituals to attract females. Once a pair has formed, they will swim together in a “T” shape before descending onto a suitable surface to lay eggs.

In captivity, these fish deposit their eggs on plant leaves or other surfaces within the aquarium. Females have the remarkable ability to produce up to 600 eggs per spawning event. After the eggs are laid, it’s important to remove the parents from the breeding tank to prevent them from consuming the eggs.

Fry Care

Raising Corydoras nanus fry can be challenging due to their tiny size and specific dietary needs. Here are some important considerations:

  • Provide a separate rearing tank with gentle filtration.
  • Feed them small, live foods such as baby brine shrimp or microworms.
  • Maintain excellent water quality by performing regular water changes.

It’s essential to monitor the fry closely and ensure they receive proper nutrition for healthy growth and development.

Breeding Corydoras nanus is a fascinating endeavor, allowing you to witness their unique behaviors and contribute to their conservation efforts. With the right conditions and care, you may soon have a thriving population of these charming little catfish in your aquarium.

Frequently Asked Questions

How big do Corydora Nanus get?

Corydora Nanus, commonly known as the Nanus Cory Catfish, grow to a size of approximately 1.8 inches when fully mature. Their small size makes them suitable for various freshwater aquariums.

What is the lifespan of a Corydoras nanus?

The average lifespan of a Corydoras nanus, or Nanus Cory Catfish, is typically around 5 to 8 years. Proper care, including suitable tank conditions and a balanced diet, can contribute to their longevity in an aquarium.

Do Cory catfish need salt water?

No, Cory catfish are exclusively freshwater fish and do not require saltwater in their habitat. They thrive in freshwater aquariums, and maintaining stable conditions with the appropriate temperature, pH levels, and water hardness is essential for their well-being.

What is the smallest Cory breed?

The Pygmy Corydoras (Corydoras pygmaeus) holds the title for the smallest Corydoras species. When fully grown, these tiny catfish reach a size of 1 inch (2.5 centimeters). Their diminutive size makes them a popular choice for nano and small community aquariums.

Do Cory catfish like sand or gravel?

Cory catfish, like the Nanus Cory, prefer sand or smooth gravel substrates that mimic their riverbed habitats. This choice allows them to forage for food and exhibit natural behaviors in captivity, making the right substrate crucial for their well-being.

Image Reference

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