How Often Do Cory Catfish Lay Eggs? Care + Breeding

Under proper conditions, Cory Catfish can lay eggs every seven days.

Each time, they will lay about 50-150 eggs in the span of one hour. During this hour, they will lay eggs in multiple batches.

Read on for a detailed guide on the egg-laying procedure of cory catfish.

How Often Do Cory Catfish Lay Eggs?

The number of times the cory catfish will have eggs in your fish tanks depends on how many cory catfish you have kept.

The more Cory Catfish you have, the more days it will take for them to lay eggs.

A fish tank having approximately 6 to 8 cory catfish will soon have the pairings formed between males and females. The eggs are laid once every week.

However, there are other factors that affect the egg-laying process, which are discussed below.

Ideal Conditions for Cory Catfish to Lay Eggs

There are certain requirements that need to be fulfilled in order to trigger the breeding process of cory catfish.

Tank Conditions

To provide the ideal breeding conditions for cory catfish, you need to make sure your tank should be as clean as possible.

Some fish owners prefer decorating their tanks to emulate the natural environment for the cory catfish.

This is done by adding aquarium décor like caves, rocks, plants, and others. The more natural the environment looks, the safer and more comfortable cory catfish will feel.

On the whole, it is best if you have a separate tank for breeding purposes only. This tank should have sand or rounded gravel.

If you opt for sand, don’t dump any excessive amounts.

Water Conditions

You should never delay replacing the tank water in case it gets dirty. Not only will polluted water hamper breeding conditions, but it will also prove detrimental to the cory catfish’s lives.

Make sure the pH level of the tank water is between 6.0 to 8.0. The temperature should ideally be anywhere between 70 degrees to 80 degrees Fahrenheit.

Cory catfish tend to breed in slightly cooler temperatures (2 degrees to 3 degrees Fahrenheit lower than usual).

When attaining that temperature level, make sure not to do it all at once. Doing so will shock the cory catfish and may affect their health.

Try to decrease the temperature slowly each day in order to give time for the cory catfish to adjust.

Feeding Schedule

The diet of cory catfish is a crucial element in triggering their breeding process. Cory catfish need to be fed twice or thrice a day to ensure they get all their required nutrients.

As a fish owner, you need to make sure they are getting a protein and vitamin-rich diet. Cory catfish can eat all types of worms, like live blackworms or frozen bloodworms.

Since cory catfish are bottom dwellers, they prefer food that sinks to the bottom, like sinking wafers or gel food.

According to fish experts, you should give cory catfish a complete diet of worms, insects, eggs, and larvae to speed up their breeding process.

How Many Eggs Can a Female Cory Catfish Lay?

A female cory catfish is able to lay between 50 to 150 eggs in an hour. Fortunately, not all the eggs will be fertilized; hence you won’t have your fish tank suddenly full of young cory catfish.

Protecting cory catfish eggs is quite important as they are prone to be eaten by either adult cory catfish or other tank mates.

A female cory catfish prefers to lay her eggs in different places in the fish tank. You will also notice how they will form the T shape.

When this happens, the ventral fins of the cory catfish will be shaped in a cup. She will then lay between 4 to 12 eggs at one go in her fins.

Once the eggs are laid in her fins, the female cory catfish will search for some grass or plant leaves.

The cory catfish will then rest for some time and resume the same process of laying eggs in a different location.

After an hour or so, your fish tank will have anywhere between 50 to 150 cory catfish eggs in various places.

How to Differentiate Between Male and Female Cory Catfish

Naturally, the mating period will only start when both sexes of cory catfish are present.

If you want to start the breeding procedure, you need to make sure there is an equal ratio of males and females.

Both sexes of cory catfish look quite similar to each other, making it difficult to tell them apart. For the best chances of mating, the male to female ratio should be 2:1.

Male cory catfish are usually thinner, more slender, and relatively smaller than their female counterparts. The midsection tends to be somewhat thicker than the females too.

Before reaching maturity, both sexes of cory catfish are practically indistinguishable from one another.

The best way to have both males and females is to buy cory catfish in bulk and put them in the fish tank.

Can the Number of Eggs Laid By Cory Catfish be Increased?

Surprisingly, yes. You will have to watch out for a lot of factors like water temperature, water chemistry, and other aspects.

You will also have to check the female cory catfish’s diet. You can increase the nutrients she takes, which will boost her egg-laying capabilities.

Apart from this, the fish tank should be thoroughly cleaned and filtered. If all these conditions are met, the female cory catfish will produce more eggs in her batches.

It is important to note that the increased difference isn’t too much. Most probably, the cory catfish will have five eggs more than usual.

How to Check if Cory Catfish Eggs Are Fertilized

Cory catfish eggs which are fertilized will be beige in color with dark spots on them.

The eggs which are not fertilized will appear white and translucent with no markings on them.

Another sign is to wait for at least a week. Fertile eggs take a week to hatch completely.

If any of the eggs do not hatch in this time frame, you can safely assume those eggs are infertile. You can dispose of them later.

What are the Signs that Cory Catfish is Pregnant

Female cory catfish will have swollen bodies when they are carrying eggs in them.

Fish owners should, however, be aware that cory catfish lay their eggs very quickly. This also decreases their swelling at a fast pace.

Cory catfish prefer laying their eggs near decorations and plants. If you notice any swollen cory catfish, you can check those areas out for eggs.

How to Deal with Cory Catfish Eggs

Once the cory catfish eggs are laid, you should immediately put them in a different tank. Separating the young cory catfish fry from their parents improves their chances of survival.

You can use a razor or your credit card to scrape them away gently. This is a highly delicate procedure that requires your full attention.

Cory catfish eggs are quite fragile and can be easily crushed. Once you have got the eggs, you should make sure they are not exposed to open air.

You can achieve this by putting them softly in an egg tumbler. Egg tumblers let the eggs remain fresh and keep the fungus away.

Some people recommend putting an airstone in the eggs’ tank. This further increases the birth rate of young cory catfish.

What to Feed the Newly Hatched Cory Catfish

The cory catfish fry will need a stable diet with proper nutrients for their growth.

It is recommended to feed them live brine shrimp. Young brine shrimp will work best because of their small size.

Cory catfish fry requires feeding several times a day for maximum growth. Missing out on even a single day of feeding can prove fatal to them.

Frequently Asked Questions – FAQs

Is breeding cory catfish easy?

Cory catfish are easy to breed, provided you have made sure the conditions are ideal for them.

You can easily have a lot of fish in your fish tank if the breeding procedure is done correctly.

Can cory catfish eggs be eaten by snails?

Yes, cory catfish eggs are always in danger of being eaten by snails or shrimps.

Snails can eat almost anything; hence you need to protect the eggs from them.

Also read: Do Cory Catfish Eat Snails?

What tank size is ideal for cory catfish breeding?

If you are looking to increase the number of cory catfish in your fish tank, we recommend going for a 20-gallon aquarium.

Since cory catfish prefer swimming near the bottom, a 20-gallon fish tank will be enough for cory catfish and other tank mates.

Also read: How Many Cory Catfish Can Live in 10 Gallon Tank?


Cory catfish make a wonderful addition to your fish tank. They are generally low-maintenance, having only a few requirements that fish owners need to meet.

However, their egg-laying process can prove to be a challenge for amateur fish owners.

It is best to make sure you have done your research before attempting to start their breeding process.

The most important aspect to remember is making sure all conditions are being met.

Keep an eye out for water temperature and the overall state of your fish tank. If everything is perfect, you will soon have lots of new cory catfish in your fish tank.

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