Cory Catfish | A to Z Guide – Care, Tank Mates, Size, and Diet
Cory catfish have great personalities; they’re calm, peaceful, and well-disciplined to begin with. They also have gentle nature and unique (dancing) characteristics, which you’ll find interesting the most.
Further, this article introduces you to one of the most suggested freshwater fishes, regardless of your fishkeeping experience. You’ll also understand the tank and water conditions to help this fish species survive.
Table of Contents
The Cory catfish (Corydoras paleatus) originates from South America’s small streams and lakes. They are also native in the regions east of the Andes Mountains extending to the Atlantic Ocean and belong to the Callichthyidae family. Cory catfish are also known as Corydoras, Cory fish, armored catfish, Cory cats, and Corys.
Aquarists find Cory cats the most peaceful, calm, and desirable fish species, making them among the desirable and endearing species to keep in a tank. Even though they’re regarded as non-aggressive, it doesn’t mean they’ll be boring—their excellent social skills and varieties of natural shades make up for it.
Corydoras are bottom-dwellers (like peacock cichlids) that constantly scrabble around the tank’s bottom layer to look for food and scraps. Since they’re friendly fish species, they’re best kept in a school of 6 or more. What’s more, breeding Cory catfish would just be a breeze as long as water and tank conditions are met (we’ll talk about this later).
Corydoras have many species, such as Albino, Panda, Peppered, Pygmy, Jullii, Bronze, and Emerald catfish (to name some). These different Cory types vary in size and color, but aquarists find the Bronze Corys the most common in the market. Nevertheless, Corydoras in shades of brown find it easy to camouflage in the substrates, protecting themselves against predators.
Further, the average size of a Cory catfish ranges between 1 to 4 inches (2.54 to 10.16 cm). Older female corydoras tend to grow even more, which extends up to 3 inches in length. Another interesting fact about Corydoras is their venomous spines.
Cory catfish got its name from the Greek word Kory and doras, which means helmet and skin. These words distinctly describe Corys’ appearance having an armored body with bony plates that run along its body. The thickness of their bodies is noticeable on their head parts, tapering off near the tail, which creates their triangular-shaped look.
As for its pins, the pectoral fins are horizontal in shape, letting Cory catfish lie on the substrate comfortably. Meanwhile, its vertical dorsal fins are pointed (round for some catfish species). They have broad, large eyes and three prominent barbels (or whiskers) that help them find scraps on the substrate.
To distinguish males from females, fishkeepers look at Cory’s profile. Smaller and thinner bodies are males, while females have rounder and more extensive profiles (essential for holding eggs).
Behavior and Temperament
Are Cory catfish aggressive?
Cory catfish are well-mannered fish species. They’re among the most pleasant types of fishes in the corner, especially when teamed with their kind. For this very reason, Corydoras may find it difficult to survive if they’re alone.
Aquarists find Cory cats love to stay close with one another. They tend to do things together: move around the tank, look for food, and rest. They’re a lot happier with others of their own kind. When threatened, Corydoras just hide and avoid hostile tank mates.
Corys are known as bottom-dwellers, meaning they tend to go around and play on the bottom layer of the tank. They typically mind their own business at the bottom, either resting or scavenging for food. Moreover, Cory catfish like to hide and rest during the daytime but are active in the evening.
As mentioned, their sweet temperament doesn’t necessarily mean they’re boring to watch. In fact, having multiple Corys at a tank is fun to watch. You’ll find them forming a school and creating a genuinely fantastic water dance!
How long do Cory catfish live?
Cory catfish lifespans are relatively longer than other fish species. They could live approximately 5 to 7 years or significantly more, given the suitable water and tank conditions.
Other aquarists note that Corydoras could even live between 12 to 15 years. Some documented cases report Corys having a lifespan of 20 years and so.
Since they’re good-natured, you won’t find yourself struggling in helping Corys survive their tank.
Cory catfish are vulnerable to several types of diseases common to fish species. Here are the conditions to look after:
- Red blotch disease. Corydoras are particularly associated with red blotch disease. It’s characterized by bloody sores on the skin, especially on the belly parts. Signs of this illness include nasty-looking blisters caused by fin rot and fungus infection. Treatment involves fixing the tank environment and medicating the infected Cory catfish.
- White spot disease. As the name suggests, white spot disease is a parasitic type of illness caused by Ichthyophthirius multifiliis that infects bottom-dwelling fish species. These parasites attach themselves and feed on the fish’s body cells and fluids.
- Gill flukes. Another disease that Cory cats are susceptible to is gill flukes. They infect a fish’s gills and skin, and once these body parts are destroyed, the infected fish dies. An undesirable tank and water conditions, overcrowding, and stress contribute to this type of disease.
Aside from the mentioned diseases, it’s worth noting that nitrite poisoning can result in Corydoras’ death. Once they’re affected, you’ll notice them move sluggishly or dwell on the tank’s top layer.
Since Cory catfish find it hard to survive alone, isolating them in a tank is a big NO-NO. Corys could die of loneliness, especially when they’re sick.
To avoid Cory catfish diseases, ensure to provide proper care and treatment. This process involves cleaning the water tank, guaranteeing water parameters are in the same condition, and feeding Corys with sufficient but nutrient-rich foods.
How big do Cory catfish get?
Corydoras grow at an average size between 1 to 4 inches (2.54 to 10.16 cm). Moreover, adult female Corydoras tend to grow even more, extending up to 3 inches in length. It can weigh approximately 0.02 pounds.
How many Cory catfish can be kept in a tank?
You’ll find Cory catfish easy to take care of, as they’re sociable, well-mannered, and peaceful to be with.
If you want to keep a school of five to seven Corys, a 20-gallon tank size will do. Further, add 2 to 4 gallons of water for every Corydoras you add to the home tank.
Cory Catfish Care
A suggested ratio of one Corydoras to 4 gallons of water is advised when keeping a school of this specific fish species. Nonetheless, the minimum tank size would be a 20-gallon tank, letting you keep seven Cory catfish maximum. Opting for a 30-gallon or more tank size would be better if you want an increased community of fishes.
Corydoras spend most of their time resting or scavenging at the bottom layer. Nonetheless, they’re easy and pretty forgiving when it comes to their tank environment. They also thrive in larger tanks as well.
Yet, it’s important to note that Cory catfish tend to dart up to the surface to grab a gulp of air. For this reason, make sure to create a tight lid covering your aquarium (or else your Corys end up swimming on the floor).
Here are the other components you might need in setting up your Corys’ tank environment:
- Sand sediments. When looking for depositions to add to your home tank, opt for soft sand. They’re the best choice for substrates because hard sand or gravel can damage Cory’s body parts.
- Driftwoods or caves. Corydoras love shady hiding spots. As such, driftwoods and caves can be their go-to spot when they want to rest or hide from aggressive fish species in the tank.
- Filtration system. Cory catfish have native streams with a slow-moving current. Therefore, make sure to create weaker and slower streams in the tank. Also, consider a canister with nitrate (and filter pad).
- Plants. Water plants are great water flow breakers, so they’re essential too. They’re beneficial in oxygenating the water and provide Corydoras a cover from the light.
- LED lighting. Corys are very adaptive to any type of lighting, so any kind will do.
- Tank covers. Finally, secure a tight lid for your home tank, as Corys have a habit of jumping to the surface for a gulp of air.
Aside from tank setup, catering to the tank’s water conditions should be considered as well. Since Corydoras are tropical fish, create consistent water parameter accommodating to the following: temperature, pH level, hardness, and alkaline level:
- Temperature. Considering the climate of Cory catfish’s origin, opt for a temperature between 70° to 78° Fahrenheit (21° to 25.5° Celsius).
- pH range. In terms of pH levels, keep it between 5.5 to 7.0 for consistency.
- Hardness (dH). The recommended dH level for keeping a community of Corys is between 15 to 18.
- Alkaline level. Your home tank’s alkaline level should be at 3 to 10 dKH.
Since Corys are vulnerable to nitrate poisoning, regularly check and test your home tank’s water for nitrate levels. These fish are also sensitive to nitrate and ammonia, which could kill them in no time. Furthermore, keep these levels at 0 ppm.
Diet and Feeding
What do Cory catfish eat?
Cory catfish aren’t that fussy when it comes to food fed to them. They’re omnivores, so a piece of meat, vegetables, and pellets helps them survive and grow.
Corys tend to scavenge the sandy substrates in their original habitat and look for worms, larvae, and small insects. They even dig with half of their face on the substrates and such up for food.
As such, any food that sinks in the tank is preferable, considering these fish species are bottom-dwellers. Other foods you might include in their diet are:
- Sinking pellets or flakes
- Shrimp pellets
- Algae wafers
- Feeder tablets
How often should I feed my Cory catfish?
You can feed Corydoras once or twice daily. Ensure to provide as much food they can eat within 3 to 5 minutes, as excessive pellets or leftovers can pollute the water tank (which isn’t good either).
Take note that Cory catfish have a habit of eating other species’ spawns. Be wary if you’re trying to breed a community of different species within the same home tank.
How long can Cory catfish go without food?
As per fishkeepers, Cory catfish can safely live and survive up to 2 weeks with no food.
Considering the Cory catfish’s calm and peaceful behaviors, you can keep the most common community tank fish that encompass the same characteristics. Ideally, other Corys can be a good fit as their tank mates.
Aside from other Corys, they can survive with neon tetras, phantom tetras, and other bright-colored fish with the same temperament.
Furthermore, Cory catfish’s possible tank mates involve:
- Ottos or plecs
- Filter shrimps (Bamboo and Vampire Shrimp)
- Nerite snails
- Freshwater snails
Despite their armored body appearance, Corydoras shouldn’t be kept with aggressive and territorial fishes. Take note that these fish species can attack or kill your Cory catfish. These involve the following:
- African cichlids
- Jack Dempsey
- Oscar cichlids
- Texas cichlids
- Aquarium crayfish
Fishkeepers find Corydoras’ breeding a piece of cake. In fact, it’s pretty easy to foster a community of Cory catfish since females can lay eggs weekly (provided with the proper water and tank conditions).
Cory catfish love a comfortable and private spot where they can breed and lay eggs safely. In this case, you’ve got two options to spawn Corys correctly:
- Creating a breeding tank. In this option, you’ll need to separate Corydoras for breeding purposes. The tank is typically bare, meaning no substrates included. After a female Cory successfully spawned fry, return them into the main tank.
- Creating a fry tank. You’ll do the opposite process in this option. In this case, fishkeepers let adults spawn in the main tank. The eggs, then, are transferred to a dedicated tank for the fry.
You can induce Cory catfish to breed by feeding them several times a day with small high-protein diet meals. You’ll notice female Cory’s carrying eggs after a couple of weeks.
Meanwhile, Cory eggs hatched between 3 to six days. You don’t need to feed the fry with any food, as they absorb nutrients from their egg sack.
To sum up, beginner and professional fishkeepers would find Cory catfish the easiest and peaceful community of fish species to be taken care of.
They’re well-mannered and get along well with other Corys or tank mates mentioned above. Another significant advantage of Cory catfish is that they aren’t fussy about foods and partners.
Despite their harmless and calm nature, you won’t find yourself bored in their tank. They move around the tank with synchronized movements, ensembling a water dance presentation!