How Often Do Cory Catfish Lay Eggs?

When we take fish keeping as a hobby, we have so many questions and over-the-cloud curiosity. And it isn’t a bad thing, to be honest, the worst thing is when you go out of curiosity. But getting a Cory catfish for your fish tank will never make you question less or bored. You will have a new thing to research about each day and the thrill of raising them is never-ending. And the best thing is the breeding season of your fish. Thinking about breeding Cory catfish can be equally nerve-wracking yet amazing. But the question remains. How often do Cory catfish lay eggs?

Well, the number of eggs and frequency of laying eggs depends on the number of Cory catfish you have in a fish tank. Each female Cory catfish will lay eggs every seven days if you maintain the optimum water parameters. But for this to happen in this very rate, you have to at least have six Cory catfish in the tank.

I know this layer of information will not do you any good. So, I have written a whole article dedicated to the Cory catfish eggs and how often they lay eggs.

I hope this will solve your dilemma and answers all the questions you have in mind.

Let’s get started.

How Often Do Cory Catfish Lay Eggs?

Now, let’s talk about the number of times you will find your female Cory catfish laying eggs in the fish tank.

But as I mentioned earlier, the frequency depends on the number of Cory catfish present in the tank. If the number is more, the days will be longer than usual.

When you keep about 6 to 8 Cory Catfish together, there is a high chance you will end up with few males and few female ones together.

The number of Cory catfish present in the tank is the indicator that suggests how many times Cory catfish will lay eggs during the breeding season.

As for the number I suggested above, each of the female cory catfish will lay eggs every seven days alternatively.

But the egg-laying process and spawning behavior in both genders will be successful only when you maintain ideal water parameters in the breeding tank.

How Can You Tell If Cory Catfish Is Male Or Female? Sexing Corydoras Catfish

The breeding only takes place when there are both genders present in the tank. Both male and female Cory catfish need to be in the tank in order to take further steps in the fertilization process.

Even the spawning won’t take place If there is no male Cory catfish to woo the female into laying eggs.

So, it will be quite important to know the difference to make sure you have both genders in the tank.

Firstly, you need to know it is not quite evident and easy to differentiate the gender between two Cory catfish.

Sexing these Cory catfish might be difficult and you can’t forcefully pair them up. The natural pairing between fish will make it easier for breeding.

So, I suggest you keep a greater number of Cory catfish together in the tank so that they can choose their own pair.

Also, the male to female Cory catfish ratio needs to be 2 to 1 in the breeding tank. If you are confused about the gender, then go for 6 to 8 Cory catfish altogether.

The probability of having both males and females Cory catfish in these many numbers of fish is nearly 100%.

This way you will not have to worry about getting both the gender separately. Just drop 8 of them in the tank and the opposite gender will themselves pair with each other.

Steps To Differentiate Male Cory Catfish From Female: Difference Between Male And Female Corydoras

There are only a few slightest hints that will help you distinguish the gender of the Cory catfish you have in the tank.

  1. Firstly, look at the body size of the fish you have. Female tends to be larger as well as plumper than the male Cory catfish.
  2. Now, coming to the fins of these fish. The pectoral fins, as well as the dorsal fin of the male Cory catfish, are longer than the female.

How Long Are Cory Catfish Pregnant?

Well, pregnancy might not be the right word when you are talking about breeding and spawning in Cory catfish.

Pregnancy is not a thing in an egg-laying fish so you might have to look at the gravid body of the fish to know if your female Cory catfish is carrying eggs or not.

Your female will be carrying eggs in their tummy from the moment they hit maturity. When male Cory catfish woos the female to lay eggs, then the gravid body of the female decreases and becomes slightly normal.

And if you are thinking about the hatching period of the eggs, then that is nearly 3 to 6 days after the female lays eggs and male Cory catfish fertilizes them.

The gravid body of the female is the evidence that your Cory catfish is carrying eggs. The development of eggs starts from the very beginning of maturity.

How Many Eggs Do Cory Catfish Lay?

Cory catfish male and female show the spawning behavior for nearly an hour or more. And female Cory catfish will lay eggs in various places.

The number of eggs varies from 50 to 150 depending on the number of eggs female Cory catfish is carrying.

Don’t worry, not all the eggs will fertilize so you will not have a tank crowded with Cory catfish.

You will have to, however, take care of few eggs so that adult ones or other aquatic beings present in the tank won’t eat them up.

Female Cory catfish are egg depositors and will put their eggs in different places in the tank.

Each time they form the t shape and the female cups her ventral fins, she will lay nearly 4 to 12 eggs in her fins.

After laying eggs in her fins, she will place them in the glass or leaves of the plants in the fish tank. Female Cory catfish will take a rest for a while before starting the same process again.

So, when the spawning session finally ends, you will see nearly 50 to 150 eggs scattered all over the tank in different locations.

What Do Cory Catfish Eggs Look Like?

When the Cory catfish start showing the spawning behavior in the tank, you will see the eggs in the fish tank wall in no time.

Female Cory catfish tend to lay eggs on the leaves, plants, decorations, or the walls of the fish tank.

You will have to look for small whitish jelly-like balls in the tank which will probably be with other eggs together.

The clutch of eggs will be attached to the walls and decorations and will be easily identifiable. The eggs will be nearly 1.88 mm in diameter.

How Do I Know If Cory Catfish Eggs Are Fertilized?

Finding out how many fish fry you are going to get can be really exciting. But this will only be possible if you know how to differentiate between fertilized and unfertilized eggs.

You might already know that only the fertilized eggs will hatch to become fry and other ones will stay in the tank with no further development.

The unfertilized eggs will rot after a while and you will have to remove them immediately after to find which ones are unfertilized.

Now let me tell you the difference between two eggs. The fertilized Cory Catfish eggs will look slightly beige in color.

The light brown or nearly a color of tea eggs are what you should be looking at if you are searching for fertilized Corydoras eggs.

The unfertilized Cory catfish eggs will stay white and will turn more whitish as time passes. But remember if there are too many eggs present in the tank and are colonized together with very less oxygen flow, then even the fertilized ones will develop fungus and turn white.

But if the water parameters are ideal and the oxygen flow is adequate, you will start to see two eyes i.e., the darker spots on the middle of the eggs.

When you start to see the darker spots or two eyes inside the eggs, then get ready to see fry in the tank soon after.

Leave behind the white or translucent and plain eggs as those ones are the infertile ones and will do no good in the tank anyway.

Frequently Asked Questions

You might have more questions related to Cory catfish breeding and eggs. Here are some answers to questions you might be wondering about.

Do Corydoras Breed Easily?

Well, there are few fish that will breed happily in the fish tank and Corydoras catfish is one of them.

So, yes, Corydoras catfish breed easily in the fish tank until and unless you provide an ideal environment for them.

Being an impatient breeder, I always wanted my fish population to increase rapidly in the tank. And hence I got what I wanted when I started breeding Cory catfish.

These Corydoras catfish won’t ask for much and will lay eggs within few days. You will end up with 15 to 20 fish fry every time the spawning session comes to an end.

If you are careful enough about the water parameters and living environment, then these fish fry will survive healthily and happily in the tank.

Will Snails Eat Cory Catfish Eggs?

Actually, you may know how fish will eat anything that fits in their mouth. But when it comes to a snail, the case will quite the same.

Any viable eggs or even something that is covered in fungus will be a great diet for your bladder snails. Not only snails but ghost shrimp will love to eat anything that will fit in their mouth.

So, both snails and shrimp will delightfully devour the Cory catfish eggs or anything else that is lying around in the tank.


In conclusion, Cory catfish do well in a group if you are planning to breed them in a home tank. Remember to keep a group of them to motivate them to lay eggs faster. Eggs will not fertilize until and unless there is male Cory catfish present in the tank to fertilize them. You will most probably end up with 15 to 20 healthy Corydoras in the tank each spawning session. But remember to give them an ideal environment to breed and for the eggs to hatch properly.

Even after all the chaos, you will have to maintain an optimum environment for Cory catfish fry to grow properly.

If you have any queries related to breeding Cory catfish or handling fry in the home aquarium, then drop a comment below in the comment section.

Good luck!!!

Happy Fishkeeping!!!

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