Bronze Cory

Corydoras aeneus

Corydoras aeneus
Green Cory. Hung-Jou Chen

Scientific Name

Corydoras aeneus

Other Names

Green Corydoras




Argentina, Colombia, Venezuela

Adult Size

2.5 inches (6 cm)




5 years

Tank Level

Bottom dweller

Minimum Tank Size

10 gallon








5.8 - 7.0


2-30 dGH


72-79 F (22-26 C)


Small, active and peaceful, the Bronze Cory is just one color variation of the same species known as the Green Cory.

In addition to color variations of green, bronze, albino, and even black, this species is one of many fish that is sometimes injected with dye to enhance its color. If in doubt, do not purchase any specimens that are suspected of being color dyed. It is also wise to avoid any that have damaged barbels, or those having a sunken belly, which indicates inadequate feeding.

Like all Corydoras, this species is armored with overlapping scales known as plates or scutes. Their fins possess a leading spine, which can be locked in place to make it difficult for larger fish to swallow them. This spine can make netting them difficult, and care should be taken when doing so. In the home aquarium, Corydoras aeneus are prized for being active, peaceful, charmingly expressive and easy to care for.

Habitat and Care

Undemanding, Corydoras aeneus tolerates a wide variety of water conditions. However, they prefer an acid to neutral pH, soft to slightly hard water, and temperatures in the middle 70's.

They are not tolerant of salt and should be moved if the tank is going to be salted. Like other Corys they prefer the company of their own kind, and should be kept in schools of a half dozen or more.

Cories like to dig in the substrate for food. To avoid irritation to their barbels, use small smooth-edged gravel or sand for substrate.

They tend to be shy and should be provided with hiding places (preferably of wood or stone), as well as floating plants to subdue the lighting. They prefer low water levels similar to the shallow waters near the banks of the Amazon tributaries that are their native habitat.


Corydoras aeneus are omnivorous and will accept everything from flake to frozen foods. To maintain them in good health a variety of foods should be offered, including live foods such as worms and daphnia. They are bottom feeders, which can prove to be a problem due to the fact that other fish may consume most of the food before it reaches the bottom. Owners should observe them at feeding time to ensure they are getting a sufficient amount of food.


Spawning Corydoras aeneus is relatively easy. Purchasing a half dozen or more young specimens at the same time will ensure having at least one or two breeding pairs. Males are usually smaller and more slender than the females, particularly when viewed from the top. Prior to breeding, they should be conditioned with high-quality flake foods, as well as fresh or frozen bloodworms and brine shrimp.

Water should be on the acidic side. Rainwater is often used to lower the pH; however, care should be taken to ensure that the water is not contaminated with toxins.

A large water change (up to fifty percent) using water that is several degrees cooler than the breeding tank, will often trigger spawning. If having difficulties inducing spawning, try simulating rain by slowly adding water to the tank using a sprinkler.

The normally shy Corydoras aeneus becomes amazingly active during courtship. Males will pursue females throughout the aquarium at a breakneck pace, stopping to rub their body and barbels against the female whenever the opportunity arises. Once the female is in the mood she will search for suitable egg-laying sites and begin cleaning several suitable locations. As the courtship progresses, the roles eventually reverse and the female begins pursuing the male.

Spawning begins in earnest when the pair assumes the classic T-position, in which the male is at right angles to the female with her head against his mid-section.

The male will turn his body so that he can grasp the female's barbels with his pectoral fins. This position triggers the release of sperm as well as one to ten eggs, which the female will grasp with her pelvic fins.

Once fertilized, the female will deposit the eggs at a site she has previously cleaned. The eggs are very sticky and will adhere firmly to the nesting site. Shortly thereafter the pair will spawn again and deposit a few eggs each time. This process continues until the female has released all her eggs, which can number as many as two to three hundred. Spawning may continue over a period of several days.

Once spawning is complete, the adults should be removed, or the eggs moved to another tank where the fry can be reared. If moving the eggs, wait for twenty-four hours before moving them. Eggs are initially almost clear but will darken as they develop.

In approximately four to five days the eggs will hatch, although that may vary based on the environment. After they are hatched the fry will live on their yolk sac for another three to four days. Initially, they may be fed infusoria or very fine powdered fry food, then move to freshly hatched brine shrimp, and eventually adult foods. Frequent water changes (ten percent daily or every other day) are critical during the grow out period.