Cory Catfish: Care Guide, Breeding, Tank Size, and Disease

Cory Catfish Overview

The Cory Catfish is a popular tank pet known by several names, including Corydoras catfish, Cory cat, and Cory fish. An inhabitant of freshwater lakes, the fish is a hardy type that can survive many environments. It boasts of a peaceful temperament, rarely standing up to defend itself against aggressive fish species.

Despite their peaceful nature, the Cory Catfish is quite entertaining. They are active swimmers that enjoy wading through the water in groups. To make their stay more enjoyable at the aquarium, therefore, it is imperative to keep at least three or four of them in a tank. It is exciting seeing them swim together, making their comical moves.

Information Chart 
Care Level:Easy
Colour:Many available varieties
Lifespan:Up to 5 years
Size:0.75 to 4 inches
Minimum Tank Size:10 gallons
Temperature:70°F to 78°F
Water Conditions:pH 7.0 to 8.0
Tank Mate CompatibilityPeaceful community

Cory Catfish Appearance

cory catfish

The Cory fish has a unique appearance too. While the rest of the body resembles most other fish species, the head is entirely different. Just like the name suggests, it has a catlike head. On both sides of the head are two huge eyes that appear to pop out. On both sides of the mouth are outstretched barbels.

Owing to the size of the head, the fish almost appears triangular. It has a slender body with a long, almost flowing tail. On this body are regular dotted patterns of white and black. These extend to the whole body.

Many species have camouflage colors to help them blend in with their surroundings, such as brown for a riverbed.

The lifespan of Cory Catfish

The typical lifespan of a Cory Catfish is up to 5 or 6 years. If well cared for in captivity, the Cory fish can live to 10 years or more.

Cory Catfish Size

The average Cory Catfish can grow from 0.75 to 4 inches long at most. The Cory is in the category of small fish that hardly grow beyond three inches. Most of them are between 1.5 and 2.5 inches. Very few go beyond this size even after reaching maturity.

Natural Habitat and Origin

The Cory Catfish belongs to the east of the Andes to the Atlantic Coast up to Argentina.

Corydoras species, under which the Cory Catfish falls, has a wide range of over 160 fish under its family, showing a wide diversity in shapes, sizes, and colors. They are known to protect themselves from predators using their body armor and venomous spines. Even the word ‘corydoras’ comes from Greek — ‘kory’ meaning helmet and ‘doras’ meaning skin. It means ‘a skin helmet/protection’.

Cory Catfish is native to South American streams and lakes. They also live in rivers, backwaters, oxbows, ponds, and marshy environments in the wild. In its natural habitat, the fish lives in between many plants. It is small-sized and is usually predated upon by bigger fish and other animals. Therefore, it stays close to plants and the bottom of streams, where it can easily hide when it spots predators.

Cory is a bottom dweller fish that prefers fine sand. It avoids coarse gravel that can hurt its barbels and fins. It also inhabits waters with a high flow. You should emulate these characteristics in its tank.

Cory Catfish Care and Tank Set-up

Tank Size and Specifications

Optimum Tank Size for Cory Catfish

Cory Catfish Tank Design

Cory Catfish are community fish that enjoy each other’s company. Stock at least four, five, or more to offer them an enjoyable stay at the tank. Depending on the number, a hobbyist needs at least a 20-gallon tank for five of them. Keep in mind that the tank should not be complete. While choosing a tank size, go for a bigger one than is required.

Tank Shape for Cory Catfish

More giant tanks are suitable for a school of Cory Catfish, but any tank that is the size of 10 or more gallons should be fine for three to four of them.

Filter Type

The filter in a Cory Catfish tank needs to allow for a medium to fast water flow. Even though Corys are used to living in slow-streams and sometimes fast-moving water bodies, keep the filter on a weaker setting to let the water flow at a medium pace.


Cory Catfish require soft sediments, as per their natural habitat. You should use a soft substrate of fine sand. You can place smooth pebbles at the bottom before you add fine sand. You can use a small and rounded gravel can for the substrate. However, since they are bottom-dwelling fish and will spend more time there, it can lead to cuts and infections if the gravel is sharp.

How Many Cory Catfish in a 10 Gallon Tank?

Ideally, a school of four to five can live in a 10-gallon tank. However, using a 15-gallon tank is often recommended for Corys to thrive. With every Cory Catfish that you add to the tank, add 3 to 4 extra gallons to the size.

Water Parameters for Cory Catfish

When pouring water into the tank, do not fill it to the brim. Allow some space where the fish will have a gulp of air. It is a ritual that is quite common with the Cory cat. Also, change the water after every two weeks. Leaving food particles in the tank for a long time may pollute the water, leading to disease.

Water Temperatures

The ideal temperature for Cory Catfish is between 70 to 78 degrees F.

Water Flow Rate

Even though the Cory Catfish are easy to care for, they will fall sick if the water quality is poor or if the water movement is too slow. They prefer medium water movement, which is best for them to thrive. You can usually find them in slow-moving streams, so having a smooth flow will benefit them.

pH Level

The perfect pH level for Cory Catfish should be between 6.0 to 8.0. Since their natural environment is warm, the pH level must not fluctuate, as they are pretty sensitive to these fluctuations. These fish will not do well in soft, acidic conditions. The Cory has a high sensitivity towards ammonia and nitrite.

The same applies to nitrate. The tank water should not have any nitrates to ensure the safety of the fish.

Water Hardness

The appropriate water alkalinity of a Cory Catfish tank should be 3 to 10dKH.

Group of Cory Catfish

Cory Catfish Tank Landscape

Best Plants for Cory Catfish Tanks

While choosing plants for a Cory Catfish tank, it is a prerequisite to select plants that can withstand the alkaline, hard water that these fish are used to. Add plenty of plant life as they often hide behind plants. There is no worry about them uprooting the plants, as they are relatively small-sized and will rarely interfere with the plants’ anchorage. An aquarist should pick many live aquarium plants such as Java Moss, Marsilea Hirsuta, Rotala Macrandra, Java Fern, Crypts, Penny Warts, and Dwarf Hairgrass, Anubias Barteri, Anacharis, Water Sprite, and Banana Plants and Star Grass.

Worst Plants for Cory Catfish Tanks

You should avoid plants that cannot stand the water conditions of the Cory Catfish to minimize damage.

Decorations for Cory Catfish Tanks

Mixing these plants with other items for decor such as driftwood, leaf litter, or pieces of rock, is an excellent addition to any tank. Adding things like a small plant or a colorful stone keep the Cory Catfish engaged, as they love playing hide and seek around these massive structures. Add plenty of decorations to spruce up the tank. It is pretty entertaining to watch fish dart around these.

Lighting for Cory Catfish Tanks

Cory Catfish need moderate to normal lighting to thrive. Use standard lighting that mimics that of its natural environment. The portions are in dark areas of vegetation and murky water or swamps in the wild, so the lighting should not be harsh on them.

Feeding Cory Catfish

Best Diet for Cory Catfish

Cory fish is an omnivore. It feeds on both plants and flesh. Being a bottom water dweller, Cory is a scavenger. The fish might misconstrue this to mean the fish only deserves leftovers. While it can happily eat most leftovers, it also requires a balanced diet. Foods that can help the Cory Catfish stay healthy include:

  • Fish flakes
  • Bloodworms
  • Algae wafers
  • Chunks of meat
  • Vegetables like shredded lettuce and cabbage leaves

How Often Should You Feed the Cory Catfish?

The Cory Catfish fish is known to scour the tank for any leftovers under the substrate. This habit makes it a great tank cleaner, and you stock it with peaceful poor feeders. While at it, do not over-feed the Cory Catfish. This practice may prevent it from moving swiftly in its tank to clear leftovers. Therefore, You should give the only food they can eat in 2 to 3 minutes to them to prevent bloating or overfeeding.

Cory Catfish Behaviour and Temperament

Are Cory Catfish societal or lone?

The Cory Catfish is quite pleasant and will rarely interfere with other fish species. As they are schooling fish, they are very friendly with each other. While stocking the Cory with other tankmates, remember they hardly stand up for themselves. Therefore avoid placing them in the tank with aggressive tank mates. Owing to their size, do not put them in the same tank with bigger fish that may eat them up.

Cory Catfish are bottom dwellers who hide during the daytime or spend time scavenging and exploring the tank bottom. They will only leave the surface to run to the top and gulp in the air quickly. They also tend to hide when they feel threatened, making them an easy choice for a community tank. However, as mentioned earlier, some of the species do have venom on their body and can release toxins that might kill everything inside the tank, so one must be vigilant while choosing which Cory Catfish to take in.

An interesting thing to observe is that Cory Catfish can eat next to its tank mates without scaring or without picking a fight with them – even if the tank mates are smaller than them.

You only need to worry about your fish’s health if they show weakness or lethargy, swim upside down, have discoloration around their gills, have white spots or mucus on the body, or refuse to eat have trouble breathing. At any of these signs, immediately take your Cory Catfish and quarantine it for some time.

Cory Catfish Tank Mates

Ideal Cory Catfish Tank Mates

Cory Catfish live naturally amongst tetras mostly. They can also tolerate other species such as various shrimps, snails, and swordtails. Some favorable tank mates for Cory Catfish would be:

Bad Tank Mates for Cory Catfish

Aggressive fish species should be avoided with a Cory Catfish tank, as they will try to injure or eat them:

Breeding Cory Catfish

Breeding the Cory Catfish is overall a complex process and requires certain conditions to be followed carefully. The tank has to be adjusted accordingly.

Lower the tank temperature to 67 degrees F. It is also essential to remove all the gravel, rocks, and ornaments from the tank. During the breeding time, an aquarist will need to infuse a vibrator pump into the tank and feed the fish a variety of pellets, live and frozen foods at least four times a day. Also, during this time, one should be careful not to fill the tank to the brim. Instead, only fill it up to 50 percent of the maximum capacity.

Once you meet these conditions, you can introduce the male and female catfish to this tank and let them acclimatize to the tank for at least a few days. When all the conditions are just right, the fish will spawn. The female then lays the eggs all over the tank. It is vital to remove the adult fish from the tank as they may eat all the eggs.

To make sure the fry hatch well, post-breeding careful measures need to be taken. It is essential to turn up the air in the tank to a complete blast and put some methylene blue to help prevent any infection. The tank’s temperature also needs to be increased by 2 degrees after every six hours until it hits 72 degrees F.

After about ten days, the fry will be swimming in the tank.

Cory Catfish Breeding Level

  • Difficult

Cory Catfish Sexual Dimorphism?

To distinguish between male and female Cory Catfish, we must notice the difference between their hues and size. They are pretty easy to differentiate as the males have a more streamlined body. The females have tight body. Their bodies are thicker around their middle.

Cory Catfish Common Diseases and their Treatment

Cory Catfish are hardy and are not susceptible to many diseases if basic hygiene is followed in the tank and proper care is given to them.

Cory Catfish Suffering from desease

Cory Catfish can fall ill if they live in poor water conditions.

High Nitrates

A concentration of nitrates can stress the fish and cause them to fall ill. You must take special care to maintain the perfect pH and avoid ammonia, nitrites, or nitrates for optimum fish health.

White patches

Corydoras Catfish may develop white patches around their mouths and barbels due to some bacterial infections. This condition is a parasitic disease and needs to be treated right away. If left untreated, they will stop eating, grow visibly thinner over time, and eventually die.

Bacterial blooms

One should avoid stirring up the bottom of the tank while cleaning or re-arranging the decorations. It can release the decaying organic matter into the water and cause bacteria which can lead to infections.

The Cory fish is quite hardy but may suffer severe damage when other aggressive fish nip its barbels. Therefore, one needs to ensure the tank is safe for the fish.

Facts About Cory Catfish

  • Cory Catfish is a freshwater fish species found in the South American water and does not face any threat of extinction.
  • They all have different coloration, depending on their species, such as white, blue, black, brown, etc. – along with spots or stripes.
  • There are at least 161 different species of fish in the family Corydoras!
  • On average, Cory Catfish are small, and some of them only measure up to an inch long.
  • Cory Catfish have many different species, each with their specialty, such as Panda Cory, Bronze Cory, Peppered Cory, Pygmy Cory, Sterbai Cory, Albino Cory, etc.
  • Some species of Cory Catfish can be pretty nasty and end up killing the tank mates when threatened or stressed.

Is Cory Catfish Right for You?

Author’s note: There are very few downsides to having Cory Catfish in your community tank. They make great, peaceful companions to many tanks and often mind their business which adds to their good nature. There are hundreds of varieties to choose from, depending on size, shape, and color, and so an aquarist is bound to find one to suit their tank the best. The only downfall is that if you’re getting them for the sole purpose of breeding, you may be in for a difficult ride, as it is not easy to make them breed in a tank.

Cory Catfish in good condition


Will Cory Catfish kill my shrimp?

Cory Catfish is a very peaceful and non-aggressive species of fish. They’re doubtful to attack or try to kill your shrimp. Shrimp is one of the ideal tank mates for Cory Catfish.

Will Cory Catfish eat dead shrimp?

Yes, Cory Catfish do eat dead shrimp or sick ones. Eating dead shrimp will not harm your Cory Catfish. To be on the safer side and avoid infections, it’s always best to remove dead shrimp in the tank.

Can I put three Cory Catfish in a 10-gallon tank?

Yes, three Cory Catfish can live comfortably in a 10-gallon tank. As a rule of thumb, one Cory would require one gallon. Depending on the size and the type of Cory, you might need to change the tank size.

What do Cory cats eat?

Cory Catfish are opportunistic feeders and will eat various things such as sinking pellet food or flakes, small insects, frozen and live bloodworms, tablets, even an occasional vegetable piece.

Do Cory Catfish need a bubbler?

Yes, they do. As these fish are bottom dwellers, they will need help to breathe in a tank. Even though they can briefly come up to the surface to live, a bubbler will provide them with constant oxygen. It will also help reduce the stress they might feel.

Do Cory Catfish eat algae?

No, they will not. The fish may eat algae wafers, but they will not eat algae growing around the tank, so they cannot be considered tank cleaners.

Why is my Cory Catfish turning white?

There can only be two reasons why the Cory Catfish are getting white spots: stress or illness. If the Cory Catfish is new to the tank, it may be adjusting to the new environment. Once that is done, it will regain the color. To be on the safer side and avoid infections by regulating the water condition might make it return to normal, or it may have developed an infection. Isolate it and run a thorough check.

How often do Cory Catfish lay eggs?

Given that the conditions are ideal, Cory Catfish can lay eggs weekly. The frequency is affected by other factors and can change.

Is gravel bad for Cory Catfish?

Yes, gravel is bad for Cory Catfish as they are bottom-dwellers. It may scrape their bellies and cause cuts or infections or interfere with their eating.


Cory Catfish only needs two things to thrive: good water conditions and a balanced diet. Cory Catfish is an enjoyable species to keep for any hobbyist due to their simple care and peaceful nature. They make for good tank companions, making maintenance easy for the aquarist. They are pretty active, alert, and engaged as they participate well in a community tank. Lastly, there are so many options to choose from for you. You are bound to find one that suits your needs perfectly, whether you’re a beginner or an advanced level aquarist!

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