Emerald Green Corydorus


Aka Emerald Green Cory, Green Cory, Emerald Green Cory Cat, Green Cory Cat, Emerald Green Cory Cats, Green Cory Cats, Iridescent Plated Catfish, Emerald Green Corydorus

Cory Cats are a popular addition to any tank for many aquarist. Cory Cats are a great asset as they are part of what is considered the clean up crew for fish tanks. The Emerald Green Corydorus is a beautiful addition to the tank with its stunning Emerald Green color. Depending on the light and the position your Cory is in, it can appear as Emerald Green or Metallic Blue.

The Emerald Green Cory Cat was found in shallow, oxygen rich rivers in the Amazon. They lived with muddy bottoms and heavily planted. They fed on worms, insect larvae, small crustaceans and occasionally some plants.  Emeralds are schooling fish which means they need to be in groups of at least 3. However, the more Cories you have in your fish tank, the happier they will be.

The Emerald Green Corydorus is a bottom dweller. This means the mainly stay at the bottom of the tank on the substrate. These impressive fish forge the bottom of the tank looking for food. This is how they are known as part of the clean up crew.  They can be very shy fish, so hiding spots such as caves or live fish tank plants will be a requirement for these fish. Fully grown the average length of an Emerald Green Cory Cat is about 3 inches long. However, a larger female may grow up to about 3.5 inches in length.

Because the Emerald Green Corydorus is a schooling fish and you need at least 3 for them to thrive, a 20 gallon tank is a minimum recommended size tank for them. There are some dwarf cory cat species and they are perfect fish for 10 gallon fish tank. Cories are best kept with water conditions at:

  • pH  5.8-8.0
  • Hardness 2-15 dGH
  • Temperature 72-80 degrees F

Emerald Green Corydorus are very sensitive to any amounts of salt so it is best that they are in a tank that you do not add salt to.

Emerald Green Corydorus are a peaceful fish and should be kept with tank mates that are peaceful also.  Because they are bottom dwellers they should pair up just fine with peaceful fish that are mid and top dwellers along with other species of Cories. Shrimp, crabs and snails may be endangered in the same fish tank as these Cories as they are part of the Cories diet.

In your aquarium, the Emerald Green Cory will eat flake food, but that should not be the only source of food for them. Sinking shrimp pellets is an ideal food along with flake food. So is blood worms and black worms.

Unfortunately, Emerald Green Cories is not one of the two known species of Cories that you can definitively sex. There are speculations that you can tell the difference between the males and females by their bellies. Some say that the males tend to have more of a yellow belly and the females may have more of a pink belly. Some also say that the female may be more broad and plump compared the males.

You may struggle to breed Emerald Green Cories for a few reasons. One reason is because they are hard to determine male from female. This means you may have 20 Emerald Green Cories before you can start the breeding process. The second reason is that Emerald Green Cories breed on weather conditions which many aquarist are unable to replicate in their home aquarium.

Unlike many other fish you may have in your aquarium that requires one male to a few females, Emerald Green Corydorus are different. You need 3 males to one female ratio in your fish tank. To get them ready to spawn you need to feed your Cories black worms and/or blood worms for several days to prepare them. After a few days you need to lower the water in the tank and add enough cold water to drop the temperature in your fish tank several degrees to imitate rain in the Amazon. You will notice when a male and a female pair up. The male will be a shadow to the female going everywhere that she goes. Once the female is full of eggs, you will eventually notice them on the bottom of the fish tank in a T position or the will be laying side by side. The female will drop about 12 eggs and then adamantly bump around the males anal fin to get him to release sperm to fertilize the eggs. Once the eggs are fertilized, the female will gather up her eggs and deposit them one by one on my surfaces and objects in the aquarium. She will go back to the male and continue this process until she has laid all of her eggs which could very well be in the 1,000’s. In order for all of this to happen though, your Cories must be comfortable and happy in the tank. This means that you are not changing the décor around, they have a soft substrate, caves to hide in and live plants.

If you can successfully get your Emerald Green Cory Cats to lay eggs, don’t get too excited and start counting them before they hatch. Cory eggs are very prone to fungus which means that they will not hatch. If one egg gets fungus and is not removed it will spread to the other eggs and possibly destroying the entire batch. Once the eggs are laid, it is best to use an anit-fungus additive to the fish tank to help prevent the eggs getting fungus. Because your Cories are scaleless you need to pay close attention to what medications you are adding to your tank. Pimafix and Melafix are safe to add to your tank but medications with Permanganate or Copper based medications are not safe to add to your fish tank. You can leave the eggs in the fish tank if you would like, just be cautious of your Cories and the other fish in your aquarium. As long as your Emerald Green Corydorus are well fed, they usually pose no threat to the eggs. However, if you have a fish such as a Guppy fish that eats it’s own fry while giving birth, your Cory eggs may very well be in danger.

Emerald Green Cory eggs will hatch in about 3-5 days later. Initially your new baby Cories will feed on protozoan organisms. After a few days they will eat newly hatched baby brine shrimp or fry food. Once again, depending on the fish you have in your fish tank will depend on if the newly hatched Cories will be eaten or not. Hopefully you can be one of the aquarist with success breeding and hatching baby Cories.