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Emerald Cory Catfish: Complete Species & Care Overview

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by Jason Matthews


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The Emerald Cory Catfish, also known as “Green Cory”, is hardy freshwater fish species that many aquarium hobbyists adore. The vivid green coloration and streamlined body shape of these fish give them a distinctive and alluring appearance. They are a great addition to any community tank because of their well-known, calm, and outgoing personalities.

Whether you’re a beginner or intermediate fish keeper looking to add a new and interesting species to your aquarium, the Emerald Cory Catfish is, without a doubt, a species worth considering. In this article, we’ll take a closer look at the background, traits, size, genders, behavior, tank set-up, tankmates, diet, reproduction, and ailments of this fascinating fish species.

Whether you’re an experienced fishkeeper looking to expand your knowledge or a beginner just getting started, you’ll find a lot of helpful information here. Let’s start exploring and finding out more about the Emerald Cory Catfish! 


Scientific Name: Corydoras splendens
Common Names: Emerald Green Cory, Green Cory Catfish
Life Expectancy: 5-10 years
Adult Size: 2.5 cm (1 in) to 7 cm (2.8 in)


HabitatRivers and streams
Origin South America
Care LevelEasy
Temperament Peaceful
Diet Omnivore
Tank LevelBottom
Minimum Tank Size20 gallons
Water pH6.0-7.5
Water Temperature22-28°C (72-82°F)
Water Hardness2-25°dH
Tank MatesPeaceful fish, avoid aggressive species

Fun Fact Corner

An intriguing fact about the Emerald Cory Catfish is that when they are looking for food, they have been observed to “dance” or “shimmy.” Quick back-and-forth movements of their barbels, used to find food on the substrate, are known as the “corydoras shuffle.” Watching this distinctive feature of the Emerald Cory Catfish species can be fun.


The Emerald Cory Catfish is native to South America. It is particularly abundant in the Essequibo, Orinoco, and Amazon basins’ rivers and tributaries. Various habitats, including muddy and sandy substrates and areas with moderate to rapid water flow, are home to these bottom-dwelling fish.

In some regions, the Emerald Cory Catfish is common and has been observed to form sizable schools in the wild. They’re known to be active during the day and typically found in shallow waters.

The Emerald Cory Catfish has recently grown in popularity as an aquarium species because of its toughness and peaceful nature. Due to their well-known hardiness, regular availability in pet stores and online fish retailers, and minimal maintenance needs, they are a popular choice for both novice and experienced fish keepers.

Appearance & Size

This species is known for its striking appearance. It has a vibrant green coloration ranging from pale lime green to a deep emerald green. The coloration is due to a combination of pigments and light-reflecting cells called iridocytes in their scales.

Their body is elongated and streamlined, with a slightly flattened head and a pointed snout. They have a pair of barbels near their mouth to find food. Their fins are clear or slightly transparent, and their dorsal fin is slightly raised.

The size of the Emerald Cory Catfish is relatively small, with adult fish reaching a maximum length of about 3 inches. They are considered small to medium-sized fish species, making them well-suited to various tank sizes. They can be kept in tanks as small as 20 gallons, but it is recommended to have a larger tank to provide them with ample swimming space and to house more tankmates.

It is also worth noting that the size of the fish can vary depending on the specific strain of the species. Some strains may grow slightly larger or smaller than others, but on average, adult fish will reach about 3 inches in length.

They have a lifespan of about 5-7 years, although it may vary depending on the water conditions and diet.

In terms of the overall appearance, the Emerald Cory Catfish is a visually striking species that is sure to add a splash of color to any community tank.


The Emerald Cory Catfish, like many other species of fish, exhibit sexual dimorphism, meaning that males and females can be easily distinguished by their physical characteristics.

Adult males tend to have a slightly more elongated and slender body shape than females. They also have a slightly more pointed dorsal fin and a more pronounced “bump” on their forehead.

Conversely, females tend to be slightly more round-bodied and have a slightly less pronounced dorsal fin. They also tend to be slightly larger than males.

It’s worth noting that while these characteristics can be used to determine the gender of adult fish, it can be more difficult to differentiate between males and females in young or juvenile fish. However, as the fish grow, the physical differences become more pronounced.

Sexing a fish can be difficult and might not be 100% accurate. In some cases, it may be necessary to consult with an experienced fishkeeper or a veterinarian to confirm the gender of a fish.

The behavior of Emerald Cory Catfish

These fish are known for their peaceful and sociable behavior, making them a great addition to any community tank. They are hardy species that adapt well to captivity and typically get along well with other fish species. They are active during the day and can often be seen swimming around in the middle or bottom of the tank in search of food.

These fish are known to form schools in the wild, and they tend to display similar behavior in captivity. Keeping them in groups of at least 3-5 individuals is recommended as it allows them to display natural schooling behavior and reduces stress on individual fish.

They are also known to be active and curious fish, and they enjoy exploring their environment.

Overall, the Emerald Cory Catfish are known for their peaceful and sociable behavior, making them a great addition to any community tank. They are active and curious fish that enjoy exploring their environment and will display natural schooling behavior when kept in groups.


The Emerald Cory Catfish are best kept in a community tank with other peaceful and non-aggressive fish species.

Some good tankmates for Emerald Cory Catfish include:

  • Tetras: species such as neon tetras, rummy nose tetras, and cardinal tetras make good tankmates for the Emerald Cory Catfish.
  • Danios: zebra danios, leopard danios, and pearl danios are active and peaceful fish that will get along well.
  • Rasboras: species such as harlequin rasboras, scissortail rasboras, and the dwarf rasboras are excellent tankmates.
  • Other peaceful community fish: guppies, platies, and mollies are good tankmates.

It’s worth noting that it’s always best to research the specific species of fish you plan to keep together, as some species may have different requirements or behaviors that may not be compatible with this species.

Additionally, it’s important to remember that the tank size and water conditions should also be suitable for all fish species in the tank.

Overall, the Emerald Cory Catfish is a peaceful and sociable fish that does well in a community tank with other peaceful species. They get along well with tetras, danios, rasboras, and other peaceful community fish.

Tank conditions

The Emerald Cory Catfish are native to South America and are accustomed to living in freshwater rivers and tributaries with moderate to fast water flow. To ensure the best possible conditions for these fish in captivity, it’s essential to replicate their natural environment as closely as possible.

In terms of tank size, a 20-gallon tank is the minimum recommended size for a group of 3-5 fish, but a larger tank is always better to provide them with ample swimming space and to house more tankmates.

They should also be provided with a sandy or fine gravel substrate which will help replicate their natural habitat and provide a suitable surface for them to forage for food.

In terms of water parameters, they prefer a pH range between 6.5-7.5, a water hardness between 5-15 dGH, and a temperature range between 72-78°F. They are also relatively tolerant to changes in water parameters, but it is important to maintain a consistent level and avoid any sudden changes.

In terms of lighting, they do well with moderate lighting. They require a light source that mimics natural daylight but also a period of darkness to rest and recover.

It’s also important to provide them with plenty of hiding places, such as caves, rocks, and plants, to reduce stress and provide them with a sense of security.

They also appreciate a good filtration system to keep the water clean and healthy.

Overall, the Emerald Cory Catfish are hardy and adaptable fish that will thrive in a well-maintained tank with appropriate water conditions and a suitable environment.


The emerald cory catfish are opportunistic feeders who consume various wild foods. In captivity, they can be fed various foods, including commercial fish food and live and frozen food.

Pellets, flakes, and wafers are a few examples of commercial fish food products they will gladly accept. It’s critical to choose a premium fish food specially formulated for bottom-dwelling fish because they typically spend most of their time close to the substrate.

They will eat various live foods, including brine shrimp, bloodworms, and daphnia. The fish can be fed frozen foods like brine shrimp, bloodworms, and mysis shrimp after they have been thawed.

They will also eat food scraps and debris that sinks to the bottom of the tank, so it’s important to keep that in mind.

It is recommended to feed them smaller meals several times throughout the day rather than one large feeding. This will assist in simulating their natural feeding behavior and prevent overfeeding.  

It’s critical to monitor their eating habits and adjust their diet to maintain their health and well-being. A well-balanced diet is necessary for the fish to thrive in captivity and to be generally healthy.

Breeding the Emerald Cory Catfish

The captive breeding of the Emerald Cory Catfish is fairly simple, and the fish typically spawn on their own with little assistance. It’s crucial to remember that breeding these fish in captivity can be difficult, and success can vary based on the unique features of the tank.

Giving them a suitable environment in their tanks that closely resembles their natural habitat is crucial. This entails giving them a sand or fine gravel substrate and a reliable filtration system to maintain clean, hygienic water. It’s also important to maintain a consistent water temperature between 72-78°F and a pH range between 6.5-7.5.

When it comes to mating behavior, the male usually starts courtship by swimming around and rubbing against the female. They swim together after the female shows signs of openness, at which point the female will release her eggs, which the male will fertilize. Within 24-48 hours, the eggs will typically begin to hatch.

It’s important to note that it’s best to remove the eggs from the tank once they have been laid and fertilized to prevent the adults from eating the eggs or fry. After the eggs have hatched, the fry should be fed infusoria or another small live food until they are big enough to eat commercial fry food.

It’s also important to remember that raising these fish in captivity can be difficult and depends on the particular tank conditions. The tank’s environment may need to be tested and altered to breed fish successfully.

Breeding the Emerald Cory Catfish in captivity is not too challenging, but giving them the right environment and water quality is crucial.


The Emerald Cory Catfish is susceptible to several diseases like all other living things. However, the disease risk can be significantly decreased with proper care and upkeep.

The most common diseases include:

  • Ich
  • Fin rot
  • Swim bladder disease

Maintaining good water quality through regular water changes and water parameter monitoring is essential to prevent these and other diseases. Additionally, it’s critical to provide a balanced diet and refrain from overfeeding.

It’s also crucial to pay attention to the fish’s behavior and appearance and act quickly if you suspect illness. If there are any signs of a disease, it is recommended to remove the sick fish from the tank and seek advice from a veterinarian or knowledgeable fish keeper for the proper diagnosis and treatment.

Overall, they are a hardy and versatile fish that can be kept easily.


Jason Matthews

My name is Jason Matthews, and welcome to my website. When other kids were bragging about how their dog could sit and roll over, I was bragging about my latest Betta Fish and the cool sea castle I just added to his aquarium. 

Jason aquariume

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