Breeding Cories

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The following article on breeding cories is based on my personal first-hand experience and basic information from other websites. Although this is about breeding peppered cories, the concepts can be applied to most types of cories. (Photography by Kissyboots)

Setting up a breeding environment:

It is best to have more males than females (3:1 or 4:1) to make sure the eggs get fertilized. Males are smaller and thinner; females are larger and rounder. The female may also be lighter in color than the male.

Male on right, female on left.

Cories usually spawn when the water temperature changes. A good range to keep the water temperature at is 68-70 degrees Fahrenheit. If the water is already in this range and the cories are not spawning, it is best to raise or lower it by 2-5 degrees. They may also spawn when the aquascaping is changed, the décor is moved around, or they are put in a larger tank. Since they are somewhat nocturnal, they will most likely spawn during the night or right before the lights on the tank turn on.

After the cories lay the eggs, the eggs should be removed from the tank or the cories and/or other fish will eat them. This can be done by sliding a credit card underneath them. Make sure they aren’t being squished. They are very sticky, so a net should be avoided. (Note: I always kept them in the water, but I am not sure if they would die if allowed to come in contact with the air.) If they were laid on a rock or décor, the rock or décor can be moved with the eggs to another tank. This might not be the best option though because when they hatch, the fry are very small and might get squished under the object. Until they hatch, they can be kept in a small container, but the fry should be raised in a tank.

Setting up a fry tank:

A 6.6g bookshelf is perfect, or any tank that has more horizontal space than vertical space, because it is not tall and therefore has more surface area on the bottom. It should be a bare-bottom tank, as in there is nothing in the tank except the filter, so it is easier to clean and the fry won’t get lost in the substrate. However, it is best to have one or two fake plants or other items. The base of the décor gives the fry a place to rest from the current. Make sure the tank is cycled before adding the fry. A sponge filter is the best option but it is also appropriate to use an HOB filter and stretch a nylon sock over the filter intake. Turning down the intake rate (if possible) is also a good idea so the fry won’t get stuck to the intake. (Note: I used a normal HOB filter and stretched a nylon sock over it.)

Here the fry are old enough that the nylon sock is no longer needed.

Raising the fry:

The fry will hatch after about five-six days. They will still be attached to their yolk sac so feeding is unnecessary for the first day. After that, they should be fed several times a day. A tiny pinch of Hikari First Bites two to three times a day seems to work well for around thirty fry. Crushed flakes and crushed algae wafers can be substituted. (Note: I used crushed flakes on the first couple batches of fry and some rejected them. I later used Hikari First Bites and had much better results. Although I have not used it before, egg yolk and baby brine shrimp can also be used. Egg yolk however can cloud the water and require more water changes.) The food should either be soaked before putting it in the tank or it should be placed directly in the water so it sinks. Do not sprinkle it on the surface of the water. It will stay there because it is so light and the fry won’t be able to eat it. (Note: I turned off the filter before feeding and left it off until most of the food was gone. This prevents the food to get sucked into the filter and/or moved around so the fry can’t eat it.) After about a month, they can be fed larger foods like algae wafers. Flakes can be used too, but they aren’t as accepted as algae wafers. After about two-three months the fry can be moved into the tank with their parents or other fish, if necessary. As long as they don’t fit in a fish mouth, they should be fine.

Daily water changes aren’t necessary, but a 25% water change is best about every third day depending on the size of the tank. The fry can be sensitive to water changes so 50% water or more should not be removed at the same time. If there is water from an established tank available, use it instead of perfectly clean water such as dechlorinated tap water to refill the tank. Small but frequent water changes can also prevent diseases like dropsy and pop-eye which can affect large groups of fry at a time.

How cories spawn:

The male swims up to the female and makes fast, jagged movements. He may chase the female around for a while. They connect into a T-shape and wiggle around a bit. Then they lie around for about thirty seconds.

Cories spawning.

The female then carries the eggs (usually 2-6 eggs) in a make-shift pouch under her and sticks them to various objects in the aquarium (glass, plants, décor, filters). Then she swims around a bit more until the male joins her again. They repeat this process over and over again until about 20-30 eggs have been laid.

Here the eggs are on a plant leaf.

The eggs turn grey after about four days. If they don’t, then they are not fertilized.

Four day old egg.

After about five-six days the cory shape is visible inside the egg:

Here is the egg right before the cory hatches.

After about five-six days the cory fry will hatch. They are about 1/2 cm long and look like tadpoles.

Here is the cory right after hatching.

After about two weeks the fry’s egg sac will be gone and they will start developing fins.

Here is a two week old cory with a full belly.

One month old cory.

Two month old cory who is ready to join mommy and daddy in the big tank!

(And thanks to Orion and Avalon for the helpful input!)

Last edited:


Large Fish
Sep 7, 2008
Considering the popularity of these wonderful creatures and the regular questions about their breeding and KB's excellent post, I suggest this become a stickie.

Thanks KB!


Large Fish
Sep 25, 2005
New York, US
Great article and pictures. You can really see every detail on the fry in those pics.

In addition to your article, I've found that daily water changes of around 15-20% are very good and provide good success rates in that it removes any uneaten food and keeps that water clean. I dont mean to contradict your article because obviously you've had success and what works for one may work a little different for another, but rather add on to it so please dont take the comment wrong :)

Great article though, you should probably make one on how to use a camera like that :p

Jan 4, 2010
North of Dallas Texas
I've been watching their "mateing" dance for weeks.... haven't seen any fry but I haven't really known what to look for. So as for me this was extremely helpful. Who knows... many a fry could have ended up falling victom to a water change/gravel & plant cleaning. :(

Thanks for the info... Now I can watch for the fry.