Dwarf or Pygmy Corydoras are charming little catfish that belie their diminutive sizes with personalities that are so much bigger. They can also be referred to as Armored Catfish, Corys, Cory Catfish, or Corydoras Catfish.
There are actually three species that are known in the trade as miniature catfish, and they are Corydoras hastatus, C.pygmaeus, and C.habrosus.
Teeny tiny in size, these little fish don’t exceed much beyond an inch at full maturity,
These freshwater fish are from South America and are highly adaptable and quite easy to care for as they are not too demanding.
They can be found in Colombia, Venezuela, Peru, Ecuador, Brazil, and Paraguay.
Let’s discover more about this fun, friendly, eye-catching species and see why these little catfish are so popular for hobbyists today.
Pygmy Corydoras Behavior
Great things come in small packages! As far as fish go, Pygmy Corys are exceptionally well behaved and unlikely to cause you to lose any sleep.
They adapt well to existing communities as a peaceful and friendly bottom dweller who excels at getting along. They are certainly not a shy and retiring species of fish, but they get on with their day without too much trouble to you or other members in your tank.
One thing that the Pygmy Corydoras has going for it is that it will actually shoal with others of its kind, often on levels higher up in the tank ecosystem, which is less typical of larger catfish species.
They possess a hybrid lung-type organ that allows them to breathe from the air when water is in poor condition, and this can be found in their intestine, interestingly enough.
They love nothing more than to root around in the soft sandy substrate in search of food.
One thing you do need to factor in is their tiny size means you do need to be careful of who you choose to house them with. They can get easily intimidated and will often lose out when it comes to competing for food.
Probably best suited to a single species tank, alongside other small freshwater fish species or perhaps invertebrates.
They do like to be social on the whole and therefore tend to do best in multiples, preferably 6 or more. This is good news for the novice because they do succeed well in even smaller-sized tanks, but you still get a decent-sized community of fish to observe and care for.
These are a species that actually do better with a reverse gender ratio of two or three males to every female.
Pygmy Corydoras Lifespan
Incredibly, these fish can live for up to 3 years in captivity which is quite astonishing for freshwater fish and for a fish of this size and stature. They reach maturity in about a year, and their lifespan will depend on which specific species you acquire.
We will discuss more on tank requirements a little later in this article.
Pygmy Corydoras Appearance
Measuring at around one inch in size Pygmy Corys are slim-bodied fish that do not have scales and display the characteristic whiskers known as barbels that all catfish possess.
Silver in color, they have black horizontal lines that are quite prominent along the length of their bodies.
Short, mid-bodied dorsal fins are spotted in black, and their caudal fin appears vertically striped.
They can ‘wink’ at their owners after gulping air which is a quite bewitching characteristic to most, and it’s thought to distribute and compress air down into their gastric tract where they can process aerated oxygen.
They can get a little larger with age as they primarily care about eating, so you do need to be careful of overfeeding.
Females are slightly larger than males and can be more rounded when carrying eggs approaching breeding season.
Pygmy Corydoras Habitat And Tank Requirements
Little Pygmy Corys come from slow or non-moving waters with soft dark substrates, quite a few rocks, and leafy river bottoms awash with fallen wood and other organic matter.
Therefore you should keep water movement reduced. Nestled into the riverbed, these bottom dwellers love to hide in amongst the debris and vegetation.
Let’s look at some specifics that are needed.
Tank Conditions
You’ll want to create a landscape constructed from sandy sediment in order to mimic their habitat in the wild.
Using their barbels (whiskers) to help them search for food, these fish need to avoid being injured on sharp objects or rough substrates that can tear their skin or damage their barbels.
Some vegetation will be in order even for hobbyists with smaller-sized tanks. Ideally, you will want to recreate the riverbed using plants like Java Fern or Amazon Swords. Try mixing it up with Dwarf Hairgrass that nicely matches their size or Aponogeton and Peacock Moss.
Driftwood is ideal as a feature, but be sure that you leave plenty of open space areas for swimming. Ensure the wood is smoothed down and has no rough surfaces that can impact their soft armor.
A heater will help keep your water temperature consistent, and you only require a basic filter to deal with the minimal bioload these little fish will produce.
Sponge filters are probably best, although canister filters with strong flow have also been met with degrees of success.
Aim to change at least 50% of the water in your tank weekly for optimum health.
Water conditions should be noted, tested regularly, and maintained as follows:
- pH of 6 – 8
- Water hardness 2-15 dGH
- Temperature between 72 – 79ºF (22 – 25ºC)
- Lighting can be standard but isn’t required over the tank
Tank Size
The minimum tank size needed is 10 gallons, but for them to really do well and thrive, you should opt for a tank that is 20 gallons or larger.
Remember that you will want a community of at least 6-10 as a baseline number, so the more room, the better despite their small size.
Choosing Tank Mates For Pygmy Corys
When it comes to choosing tank mates for your Pygmy Corys, you will need to stick to the smaller end of the scale or risk them being considered food for thought.
You still need to ensure that parameters are similar and keep size in mind. Small mid-water or surface fishes would be ideal to complement your Corys.
Here are your best bets if you wish to have other fish alongside your Pygmy Corys:
- Rasboras
- Pencilfishes
- Hatchetfishes
- Blue Eye Rainbowfish
- Lamp Eye Killifish
- Danios
- Freshwater shrimp species
- Dwarf Gourami
- Mollies
- Cherry Barbs
- Neon Tetras
- Guppies
- Otocinclus
- Kuhli Loaches
- Chinese Algae Eaters
- Cherry Shrimp
- Mystery Snails
Avoid anything like larger Catfish species, Angelfish, or more aggressive types that will stress out your little Corys. You might also wish to avoid other bottom dwellers to keep territory free, which is at a premium.
Feeding Pygmy Corydoras
A variety of food types are ideal for keeping your Cory population in good health. As long as you provide something small enough for their tiny mouths (riding beforehand if necessary), they should do well.
Daphne or Artemia nauplii are good sources to feed and can be of the live or frozen variety.
Other foods to consider are baby Brine Shrimp, Microworms, as well as commercial flaked or pellet-type feeds.
Pygmy Corydoras Common Health Issues
As always with captive fish, it’s about the water quality and condition that plays the biggest role in whether or not you have healthy fish.
Frequent water changes are a must, particularly because many novice hobbyists use such small-sized tanks.
Like most freshwater species, Pygmy Corys are susceptible to Ich or White Spot Disease.
This parasitic disease presents as white spots on the body of the fish but can be treated with medication. Isolation of the afflicted will help prevent spread within your population.
The other main health issue to watch out for with Pygmy Corys is Red Blotch Disease which evolves from environmental stress. Key symptoms to look out for here are sores on the fish belly which are bloody and open. These fish are prone to this illness, so tank maintenance is a real must in order to avoid this issue.
How To Breed Pygmy Corydoras
There is little difficulty in rearing Pygmy Corys. In fact, they will breed regularly, and the bigger issue can be dealing with plentiful fry.
Given their tiny size, you should normally set up a breeding tank with a basic sandy substrate and a sponge filter that will protect any developing young.
Females will usually appear swollen with eggs, and when this becomes apparent, do a 50-70% water change using cooler water and increase oxygenation in the tank. Continue doing this daily until spawning occurs, which shouldn’t take too long.
When spawning does happen, eggs will usually be visible on the glass where water flow is high.
Eggs are released one by one at a time, and if you have a group situation in the tank, females can be spotted being chased by males who want to be involved in fertilizing the next release.
Once spawning is complete, you will ideally want to remove the adults, or chances are high that they will consume their eggs.
Fry will hatch in approximately 3-5 days and can then be fed on infusoria-type foods for a few days until they can manage micro worms.
Conclusion
Pygmy Corys are easy to care for for the uninitiated, and their small size and tank requirements make it simple for more aspiring enthusiasts to take up the hobby.
They are interesting to watch shoal, which is rare for a bottom dweller and their peaceful nature makes them ideal for mixing up communities of a similar size.
With a unique charm all their own, Pygmy Corys are great fun and have a lot to offer the amateur in the way of character, interesting behavior, and social attitudes.
