Fish

An A-Z Cory Catfish Care Guide—How To Best Keep Your Cory Fish!

An A-Z Cory Catfish Care Guide—How To Best Keep Your Cory Fish!

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Cory catfish (corydoras) is a genus of several types of bottom-dwelling tropical fish that are quite common with aquarium fish keepers. Corys are peaceful, social (good community fish), and pretty easy to care for, and perfect for a beginner.

The fish grow to an average length of between 0.8 and 4.7 inches depending on the type, but the most common size is 2.5 inches across all corys. Which means you’ll get a cory for a tank anywhere from a small size tank to a large community aquarium.

Moreover, corydoras are bottom dwellers with scavenger like tendencies, always sorting through the substrate looking for leftovers. For this reason, the fish make part of the very few tropical fish that can clean your aquarium.

The size of the tank you use will mostly depend on the species you want to maintain, though most cory catfish will fit anywhere from a 10-gallons to 30-gallons tank, with some like the dwarf corydoras able to survive even in a nano aquarium.

To best keep and care for your cory fish; add them in a planted aquarium decorated with driftwood, and layered with a dark substrate.

Plus use dim-lighting and feed them a quality sinking flake food or pellets, with regular servings of live or frozen flesh foods like bloodworms and daphnia.

That said, to help you understand how to keep cory catfish better, in this article we’ll dive a little deeper into the cory tank and explore everything you’d need to know including habitat, size, lifespan, tank, food, breeding, and more.

Cory Catfish Overview

Cory catfish are native to South America, widely distributed, with the fish present in almost every country in the continent.

The species display a broad diversity of body shapes and coloration, with some types more popular and common in the trade (bronze corydoras) than others like Julii cory.

Even so, all species are typically small bodied (0.8 to 4.7 inches) and are protected from predators by their body armor and their sharp ‘venomous’ spines.

Durable and hardy, the fish lifespan can be long compared to other small-bodied fish, averaging 5 years or slightly more under the right conditions.

However, they are quite sensitive to water changes, hence it is not uncommon for corys to die if not acclimated properly.

Cory Catfish Types

The cory catfish genus is made up of a several small, peaceful, bottom-dwelling scavengers that mostly need to be kept in schools of at least 6 individuals, together with other small to medium-sized and equally docile fish.

All types are armored and will keep your aquarium clean by finding, and eating bits of uneaten food and other debris.

Even so, (as I mentioned before) some cory catfish species are more popular and common in the aquarium fish trade than others, they include:

#1 — Bronze Cory

Bronze and pepper corys are hands down the most commonly kept members of this family.

Consequently, they are also both available in several color morphs including green, bronze, albino, and black. Bronze corys do well in a range of conditions but should be kept in schools.

  • Size: 2.5 inches
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Temperament: Peaceful
  • Tank Conditions: 72°F to 80°F, ph 6.0 to 7.0

#2 — Peppered Cory

Also called pepper cory, this cory catfish species, like the bronze cory is quite popular in the aquarium fish trade with a couple of morphs available.

Even so, pepper corys are generally tan with dark green and black patterns and often possess a green shine. That said, no two peppers are the same; a trait a lot of aquarist love.

In an aquarium, they are peaceful and get along with virtually all species, but should not be kept with large aggressive species.

  • Size: 2 inches
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Temperament: Peaceful
  • Tank Conditions: 72°F to 80°F, ph 6.0 to 7.0

#3 — Panda Cory

The pada corys are probably the most social of their family and have been known to school along with other bottom dwelling species, though they should still be kept in a group.

Also, they are quite adaptable, but prefer cooler water temperature and are capable of living in unheated aquariums.

Panda corys are characterized by a cream-white body with black spots on their head and tail.

  • Size: 2 inches
  • Minimum Tank Size: 10 gallons
  • Care Level: Intermidiate
  • Temperament: Peaceful
  • Tank Conditions: 67°F to 77°F, ph 6.0 to 7.0

#4 — Julii Cory

Julii corys are desirable gems, but they are really elusive, with many pet stores selling wrongly labbeled three stripe corys (corydoras trillineatus) as julii.

The two species are eerily similar but the three lined cory can be distinguished from a julii by the spots on the head which are connected in a long string giving them a maze like appearance.

Whereas, true julli corys have spots that are mostly not connected into long chains, though they are still part of the three stripe corys.

  • Size: 2.5 inches
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Temperament: Peaceful
  • Tank Conditions: 73°F to 79°F, ph 6.5 to 7.8

#5 — Bandit Cory

The bandit cory is so named because of a black mark over the eyes that is reminiscent of a burglar’s face mask.

The species has been in the aquarium trade a long time and is one of the more common type. However, bandits are more sensitive to variations in water temperature than other corys.

  • Size: 2 inches
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy to Intermidiate
  • Temperament: Peaceful
  • Tank Conditions: 72°F to 79°F, ph 6.5 to 7.0

#6 — Pygmy Cory

Pygmy corys are the most unique cory catfish species with tiny bodies that barely top an inch, and are capable of living in the smaller aquariums than other types of corys.

Also, unlike other types, dwarf corydoras don’t spend all their time at the tank bottom, in fact, they prefer to swim about in the mid tank area.

  • Size: 1 inch
  • Minimum Tank Size: 10 gallons
  • Care Level: Easy
  • Temperament: Peaceful
  • Tank Conditions: 72°F to 80°F, ph 6.4 to 7.4

Other common cory catfish perfect for a home freshwater aquarium include:

  • Three stripe cory

  • Skunk Cory

  • Sterbei cory

  • Albino cory

  • Emerald Cory

Read this article for more insight on the popular cory catfish type you can keep in your tropical fish tank.

Cory Catfish Tank Requirements

Cory catfish are native to small rivers and lakes across South America that are rich with live plants and other hiding places.

The floor of these water bodies are mostly sandy, with the water slow moving and almost still (but seldom stagnant) where the shallow is very clear.

Corys like to live in the banks and sides of streams that are covered with dense growth of plants, but the water conditions can vary widely.

However, they tend to prefer soft, neutral to slightly acidic or alkaline ph and 5 to 10 degrees of hardness. They can also tolerate a small amount of salt albeit some species able to tolerate none at all.

In th aquarium, cory catfish are therefore well suited to tropical freshwater community tanks. They get along well with other species and are not at all aggressive.

The fish don’t require large tanks and are pretty forgiving when it comes to water quality. Usually, a single cory catfish will be fine in a 10-gallon aquarium (depending on the type) although corys are not happy when kept by singly.

Ergo, keep a school of 6corys or more in a minimum tank size of 20-gallons or more.

Corys will thrive in larger tanks too, especially since the bio-load task in smaller fish tanks can be overwhelming and it is imperative to be mindful of fish count and to be weary of overstocking.

Add a couple of live plants the fish tank to create enough hiding spots for the fish, and particularly add floating plants to reduce the light getting to the fish. Moreover, use dimmer lighting in the tank to simulate cory’s natural habitat.

Since cory catfish are bottom-dwelling scavengers, they regularly dig the substrate looking for food, so make sure you use a soft sand substrate to base your tank and keep your corys from injuring their barbels.

Water Conditions

Cories are generally hardy and will tolerate a wide range of water conditions and temperature, but they prefer soft, tropical water with a fairly neutral ph.

Generally, they love temperature range between 70°F and 80°F, and a hardness of between 3 dkH and 10 dkH. That said, wild form corys can be a little picky compared to aquarium bred types that have hardened overtime.

In regard to water movement, cory catfish can live in fairly calm water, especially since they breath air from the water surface and consequently do better in low-oxygen environments.

Be that as it may, when keeping corys, water stability is much more important than hitting the perfect ph and temperature, so do try to keep your aquarium conditions as stable as possible. Plus beware that some species like bandit cory are more sensitive to water variations than others like bronze cory.

The fish are also sensitive to water quality, especially to toxins like ammonia and nitrite, so make sure your tank is properly cycled before introducing any new cory to your aquarium.

You can use anywhere from a sponge filter to a hang-on-back filter and anywhere from a 100 watt heater, but make sure the equipment is rated for your fish tank size.

Which Fish can Live with Cory Catfish? (Tank Mates)

All cories are peaceful, well-behaved fish that are perfect for a community fish tank. They can accomodate a host of aquarium species especially small to medium docile fish, preferably those that occupy different water levels than the cory.

Even so, large, boisterous or aggressive companions should be avoided.

Impressively, corydoras catfish and betta fish can make great companions when the fishes conditions are matched and you are sure your betta is not outrightly belligerent.

Corys are also particularly social with others of their kind, so consider keeping them in a large school and maybe with other cory species if your aquarium size allows.

Good corydoras tank mates include mollies, guppies, swordtails, neon tetras, danios, gouramis, rasboras, peaceful barbs, and inverts like shrimp (especially when keeping pygmy cories).

That said, avoid keeping your corydoras with cichlids (unless they are peaceful dwarf types like kribensis or German blue rams), and nippy species like tiger barbs.

Fast swimmers will stress and outcompete the corys for food as well, so be cautious when maintaining them together.

Cory Catfish Food—Diet and Feeding

The main source of food for wild cory catfish is bottom-dwelling insects, larvae and various worms, as well as some plant matter. They also eat flesh from dead fishes, although they are omnivorous and not piscivorous.

In the aquarium, corys will therefore eat almost anything they are offered, and will find some of their food by scouring the tank bottom. But don’t assume your fish can get enough food simply from leftover scraps.

That said, for a good, balanced diet, feed your cory catfish both plant based and meat based food and ensure they are the sinking type.

Algae wafers and most quality sinking flake food or pellets are especially good everyday choices. For the occasional meaty snack, bloodworms are a good bet.

Remember to feed your corys servings they can finish in 3 to 5 minutes and remove any leftover they don’t seem to like. This will keep your water quality safe, free from ammonia and nitrites.

One other thing; while corydoras catfish are really good tank cleaners that will even move the surface gravel around digging for dirt, they should not be considered a substitute for proper tank care.

Moreover, they are better cleaners with help from other bottom cleaners like shrimp.

Breeding Cory Catfish

Corydoras are relatively easy to breed particularly if you regulate your aquarium temperature appropriately.

For breeding purposes, lower the temperature of the water gradually down to 72°F to simulate the wild spawning season weather. A ph of 6.6 to 7.0 is perfect.

Simulate a long day as well by leaving the lights on from morning until night (at least 12 hours) before you start lowering the temperature 2 degrees per day and continue until it gets the 68°F mark.

Feed your corys inducers to encourage spawning, which means a diet that include frozen or live food together with the regular pellets at least 4 times a day.

It should take about a month to condition cory catfish for spawning.

However, before setting the spawning environment and conditioning your fish, you will need to select spawning pairs (about 5 to a dozen mature corys) and place them in a breeding tank that is 20 gallons or more.

Preferably, your breeder should be 24 inches long, with a hood and lihgt, plus a soft sandy substrate. Add stones, coconut shells, flower pots or tree rots and floating plants to provide enough area for the fish to lay their eggs.

A sponge filter with an airpump and a 100watts heater should be good enough for breeding cory catfish.

Choose fish that look healthy, plus the females should look plump, add at least 2 males in your breeding tank as well.

Spawning

Usually, while spawning, a female cory fish will press her mouth tightly aganist the male’s pelvic area to form a T- shape. The the male fish will release sperms which pass through to the eggs held in her cupped pelvic fins and they’ll become fertilized.

There is a chance that other males will try to push themselves into the T-position but mostly its the strongest male that succeds.

The female cory will then search for a spawning site to lay her eggs. Usually, corys will lay their eggs around the sides and bottom of the tank, especially on an area of a plant, aquarium glass, stone, caves or other deocrations.

After your fishare done spawning, you’ll want to net and place them back into the regular aquarium to keep them from eating their eggs.

In about 10 days, you should have a few hundred fry swimming all over the place ready to eat. Feed them live or frozen baby shrimp for about a week then a variety of fine flake food, daphnia and microworms.

Also, start changing a little water everyday to keep your cory fry safe, and use a sponge fillter to clean the tank. In about 3 to 4 weeks, you can add more filtrations to deal with the increasing bioload.

Sexing Your Cory Catfish

It can be pretty challenging tosex corydoras, but if you have to keen eye, it is possible to tell mature males from females by comparing them.

Mostly, the males have streamlined bodies, while females have more compressed bodies that are thicker at the abdomen and also higher in structure.

To put it another way, males tend to be smaller and generally skinnier than females, though it is technically impossible to tell the difference until the fish are fully grown.

Having said all that…

…have fun keeping cory catfish!

Eddie Waithaka

Resident Content Creator and Marketer at AquariaWise who talks about aquariums and fish and aquascapes a lot.

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