Emerald Cory Catfish (Corydoras splendens): Ultimate Care Guide


The Emerald Cory Catfish (Corydoras splendens) also known as the Green Catfish or Emerald Brochis can be found in the Amazon River freshwater basins in South America, specifically western Brazil, southeastern Colombia, eastern Ecuador and eastern Peru.  It has an iridescent, emerald green body with pink and yellow tones on its underside.  This fish adds an ornamental presence to your aquarium while also serving as a useful cleaner of uneaten food on the bottom of the aquarium as the Emerald Cory Catfish is a scavenger. Many hobbyists enjoy the Emerald Cory Catfish because, even though they are bottom feeders, they are generally active, alert, and fun to watch.  For example, the manner in which they interact with their tank mates and different types of snails and shrimp can be entertaining and interesting.

Emerald Cory Catfish Care

The Emerald Cory Catfish is a very hardy and resilient fish.  Disease should not be a concern provided that you maintain the aquarium to standards.

Emerald Cory Catfish Temperature & pH

The Emerald Cory Catfish should dwell in an aquarium with a temperature that is maintained between 72 and 78 degrees Fahrenheit (22.2 to 25.6 degrees Celsius).  The pH of the tank should be maintained neutral to slightly basic at 7.0 to 7.8.   These fish have been observed to live in conditions with temperature ranging from 68 to 82.4 degrees Fahrenheit and with pH values between 5.0 and 8.0; however it is recommended that you maintain your temperature and pH at the values mentioned above.  The Emerald Cory Catfish is somewhat flexible but sudden changes of temperature and pH should be avoided.

Emerald Cory Catfish (Corydoras splendens)
Emerald Cory Catfish (Corydoras splendens)

Emerald Cory Catfish Size

The Emerald Cory Catfish is a larger member of the Corydoras family and are generally 2 ¾ to 3 inches (7 – 8.4 cm) in length as full-grown adults.  However, a larger female may grow up to 3 ½ inches. They are typically one inch in length when purchased. Their diameter can range from about the size of a dime to about the size of a nickel.

Emerald Cory Catfish Tank Size

The Emerald Cory Catfish is a schooling fish that thrives in a school of between 3 and 8 fish.  For schools of three fish, a minimum tank volume of 20 gallons is recommended. For schools of fish six or greater, a minimum tank size of 55 gallons is recommended.  There is some guidance that one Emerald Cory Catfish can be maintained in a 10 gallon tank.  We highly recommend against housing an Emerald Cory Catfish without a school of at least two of fish. 

Emerald Cory Catfish Food & Diet

The Emerald Cory Catfish is not a picky eater.  They are scavengers and in the wild they are comfortable eating whatever nutrients are available on the basin floors.  In captivity, it is recommended that they are fed algae (sinking) wafers, fish flakes, bottom feeder tablets, shrimp pellets.  They are not great swimmers so you may consider feeding them food that the other fish in your tank would not be interested in.  Additionally, they thrive on a diet of live food as well.  Consider feeding them, regularly or as a weekly treat, live blackworms or frozen bloodworms.

Although the Emerald Cory Catfish is a bottom-feeding scavenger, it will not eat the algae that may grow on your tanks walls and substrate. Although, as mentioned, they may eat sinking algae wafers, you cannot rely on them to clean up the surfaces of your tank.   

Emerald Cory Catfish Lifespan

The Emerald Cory Catfish, if cared for diligently, can live as long as 13 years.  Their expected lifespan is five years.  However, it is not uncommon for the Emerald Cory Catfish to die shortly after being added to the tank.  It is speculated that this is due to the stress of the transition, or more likely, a sudden change in temperature and/or pH.  Therefore, it is recommended to match the temperature and pH of your tank to the tank that they were bred in.   

Emerald Cory Catfish Tank Mates

The Emerald Cory Catfish is a peaceful fish.  Appropriate tank mates include most community tank fish except for those that may be aggressive and territorial in nature such as Oscars, Texas Cichlids, and Jack Dempsey.  These aggressive fish may injure the Emerald Cory Catfish or potentially even eat them. 

Emerald Cory Catfish Tank Setup

The tank setup for the Emerald Cory Catfish is relatively straightforward.   Since they are bottom dwellers, it’s recommended to maintain at least two inches of gravel or substrate on the tank bottom. These fish seem to thrive in a tank with lots of live plants.  These aquarium plants provide cover and hiding places for the Emerald Cory Catfish to rest.  Additionally, include rocks and decorations that provide nooks for the Emerald Cory Catfish to explore.  Standard community lighting for the tank is recommended. Ammonia and Nitrate levels should be kept at 0 ppm.  Regular partial water changes are effective at preventing nitrate buildup. 

Emerald Cory Catfish Breeding

Breeding the Emerald Cory Catfish can be challenging.  This is for a few reasons.  You generally need a ratio of three males to one female for successful breeding.  However, it is challenging to tell the difference between males and females.  Therefore, you may need 20 or more fish before you can start the breeding process.  Some speculate that you can tell the difference between males and females by the size and color of their bellies.  Specifically, some say that the males have more of a yellow belly and females have more of a pink belly.  Additionally, some say that the female may be larger and plumper than the males.  Additionally there is speculation that they are difficult to breed because weather conditions (such as hard rain) may jumpstart the breeding process in the wild and this is challenging to simulate in captivity.

To maximize your chances of success in breeding the Emerald Cory Catfish, feed your fish black worms and/or bloodworms for several days.  After a few days of eating these worms, lower the water level in the tank and add colder water to the tank.  This will drop the temperature of your tank a few degrees which can imitate the consequences of heavy rain in the Amazon.  Be careful not to drop the temperature of the tank more than 2-3 degrees as this could be too large of a shock to the fish. 

The breeding process begins with a male and female pairing up.  The male will follow the female like a shadow. When the female is full of eggs, she will drop around 10-12 eggs which the male will then fertilize. When the eggs have been fertilized, the female will gather up the eggs and place them one by one on surfaces and objects in the tank.  This process will repeat until up to 1,000 eggs are fertilized.   Emerald Green Cory eggs will typically hatch 3-5 days later.

Where to Find Emerald Cory Catfish for Sale?

Emerald Cory Catfish can be bought at your local fish store.  You can expect to pay between $10 and $35 for an Emerald Cory Catfish depending on its size and features.

Fish Laboratory

With decades of collective fishkeeping experience, we are happy to share the fish care tips that we've picked up along the way. Our goal at Fish Laboratory is to keep publishing accurate content to help fishkeepers keep their fish and aquarium healthy.

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