Pygmy Corydoras

Pygmy Corydoras Care : Diet, Tank Size, and Mates – 2023

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Sean Green

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Sean Green

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Compared to other aquarium fish, pygmy corys are relatively forgettable, possibly due to their small size and lack of color. But through learning about them, you’ll come to find that even the smallest fish can be among the most strange, unique, and interesting marine life to acquire.

Below is an extended guide for how to properly manage the pygmy cory fish. So whether you’re a beginner or are looking to liven up your aquarium’s ecosystem, you will consider the pygmy cory to be the perfect pet and addition to your aquarium.

Pygmy Cory Closeup

What Type of Fish is a Pygmy Corydoras?  

Pygmy corydoras (or pygmy cory) belong to the genus Corydoradinae and Callichthyidae family, a type of armored catfish. Thus, it’s oftentimes referred to as the pygmy catfish and can be found off the coasts of Peru and Ecuador. Its original species, or holotype, originates from the tropical waters around South America, specifically in Brazil’s Madeira River basin. And like many marine animals, the pygmy corydoras are kept as freshwater pets.

Pygmy Corydoras Species Characteristics  

Taking a closer look at the pygmy cory reveals the distinct barbels, or “whiskers,” of a typical catfish. Two black lines stretch across its body, one extending from its tailfin to its mouth. In all, the pygmy cory has two pectoral fins, pelvic fins, and a single dorsal fin, adipose fin, and caudal fin (tail fin).


The pygmy corydoras’ name says it all. Pygmy comes from the word pygmaeus, which is dwarf in Latin. Corydoras is derived from the Greek word corys, meaning helmet, and also the Greek word doras, or skin. This gives insight into their phenotype; a bony-plated backside rather than scales, like other species of armored catfish.

An endoskeleton can be clearly seen through the pygmy cory’s translucent skin. Before they develop, young pygmy cory will start out shaped like tadpoles. They can be seen darting around in a mass of dark spots. Over the next few weeks, barbels, some coloration, and rigid lines will become noticeable as their endoskeletons form.

As an adult, female pygmy corys’ develop rounded pelvic fins. Male pygmy cory pelvic fins, as well, but they’re more triangular. You can tell the difference between the two by looking at their size and shape as well.


As one of the three dwarf species of the corydoras, the pygmy cory fish are typically able to grow up to 2.1 centimeters. The male tends to be smaller, while the female is rounder and bigger in comparison. Females can grow up to one inch in length, or 2.5 centimeters.


Unfortunately, the pygmy cory cat does not survive long: on average, they will reach the end of their lives in three years. At the end of their lives, you may observe odd behaviors from them. Some of which being discoloration, lethargy, and the refusal to eat.

It’s important to note that not only can it be a sign that they’re nearing the end of their lives, but also a sign of poor health or disease. The cleanliness of the water, alkalinity, the quality of their food, and the presence of predators will determine their lifespan at the end of the day. More inconspicuously, the health of their tank mates will play a role as well.

Behavior and Temperament  

Trust the pygmy cory to be completely docile. Like most animals with camouflage, they tend to scare easily and are hard to discern in mute shades of substrate.

Due to their small size, they are wary of predators and will often hide, their plastic-like bodies absorbing the colors behind them. You will often find them swimming at the bottom of a tank.

However, in large groups of their breed, they tend to be more confident with moving about in an environment. They are considered community fish because of how peaceful they are and can be paired up in a tank with other small species of fish.

3 Pygmy Corys

Pygmy Cory Care  

Pygmy corys aren’t nocturnal; they’re usually active during the day. They require two meals: once in the morning and in the evening. And at night, they do settle down. Most people feed them catfish pellets and algae pellets. However pygmy corys are omnivores that eat quite a few smaller species like:

  • Micro worms  
  • Brine shrimp  
  • Mosquito larvae  
  • Nematodes  
  • Artemia  

These small species are often bought frozen and fit for their small mouths, but it’s possible to feed them organics through decomposition. Placing pieces of greenery into the tank to decompose create what’s called infusoria. Infusoria, or micro-organic food, is ideal for a school of pygmy cory and the development of fry.

Next is the quality of the freshwater. Freshwater refers to the quality of water in rivers and lakes that has a lower salinity than saltwater, but this definition is sometimes wrongly interchanged with tap water. Tap water contains chlorine, which can kill the necessary bacteria in the water and damage fish. If you use it, you will need to use a water conditioner to make it more habitable for marine life.

And though pygmy corys are freshwater fish, the calcium and pH level of the water affects the health of marine life. If the alkaline is high (10 and above), algae and coral will grow. Lower levels throw off the pH balance and can affect the development of the marine life in the tank. A wide range is possible for pygmy cory: between 2-15 dkH. Thus, a level of 6 – 8 is best to meet the alkaline needs in a community tank.

Must watch video on Pygmy Corys:

Required Tank Size  

Beginners often use sizes between 10 – 20-gallon tanks, depending on the amount of pygmy cory fish you have. If adamant about using a certain size, one must consider the limitations. It’s recommended that pygmy corys get at least 1-2 gallons of space per fish.

How Many Pygmy Cory Can You Have in a 5 Gallon Tank?  

Pygmy corys are a shoaling fish, so no less than 4 cory fish is recommended on average no matter what tank you’re using. However, it’s not a good idea to keep them in such a small tank. A single fish can thrive in a small space, but most aquarists agree that a larger tank is preferable for their tendencies to dig, hide, reproduce, and swim in coordinated groups.

How Many Pygmy Cory Can You Have in a 10 Gallon Tank?  

10 gallons is the minimum size for 6-10 pygmy cory. This is the standard size and is not enough space to reproduce. If a 10-gallon tank is used, it’s suggested that the 6-8 pygmy corys are of a single gender. However, pygmy corys came from vast tropical oceans and therefore require larger concessions to be made to closely mimic their previous lifestyles.

How Many Pygmy Cory Can You Have in a 20 Gallon Tank?  

20-gallon tanks are preferable for all the pygmy cory’s characteristics listed above. Not only are they able to find a spot to place fertilized eggs more comfortably, but other fish can also live amongst them.

Up to 20 pygmy corys can live in this tank, but the fry may need to be moved to a separate tank. Such a number makes the small fish more noticeable and confident. At that level, they put on impressive schooling performances, enhancing the beauty of an aquarium.

Pygmy Cory Diet and Food  

Algae, nematodes, and plant life live at the bottom of the ocean floor. Pygmy corys tend to spend a lot of time digging for food on the seafloor. And pygmy cory, of course, being bottom feeders and omnivores, are enticed to eat smaller organisms. If in an aquarium, they will do well with nutrient-dense pellets or frozen foods like bloodworms and brine shrimp. However, they will eat cheap flake food as well.

As omnivores, they eat a variety of plants, smaller organisms, and microorganisms and are not high maintenance in small schools. If feeding anything organic, remember that their mouths are much smaller than their bodies. Just be careful of the kinds of smaller aquatic life you introduce them to because they are known to eat baby shrimp.

Tank Requirements  

The water should be soft, with a pH between 6.4 and 7.4. They prefer a warm climate between 70-78 degrees Fahrenheit. Smaller tanks will not do for these fast breeders; small tanks will need excessive water changes and cleaning. The tank itself should be longer in width than length and lidded. Pygmy corys are fast swimmers and excellent jumpers.

And though they are small species, they are used to vast waters, which may be beneficial for their growth and health. They may prefer organic greenery in their tank for food and reproductive purposes. They tend to come up for air as well, so a few inches of air at the top may be preferable. Lastly, an efficient filter and aquarium lighting.

Tank Mates  

Corydoras are completely peaceful as long as their tankmates can match their docility. Because of this, several fish of similar size can make a perfect mate for them. Popular pair ups would be with the following:

  • Dwarf Gourami  
  • Otocinclus catfish  
  • Guppies  
  • Ember/neon tetras  
  • Adult shrimp  
  • Snails  
Just be careful not to pair them with smaller fish or the babies of other fish in the tank. Some people believe they will eat their own eggs, let alone the eggs of their tank mates.

Common Diseases  

Pygmy corys suffer from similar diseases that other freshwater fish do. The most common one is the “red sore disease,” where lesions and red spots pop up along their abdomens from harmful bacteria. This can be due to overcrowding and poor water quality. At its worse, there’ll be fin erosion and death.

Undoubtedly, it’s hard to determine with the eyes; it could be that they’re nearing the end of their lives. To treat it, one could do a salt dip or allow it to heal on its own if problems aren’t systemic. Symptoms and certain factors make fish more susceptible so be sure to inform yourself of more ways to treat it and preventative care.


How Many Pygmy Corys should be together?

Pygmy corys normally travel in schools in the wild. As a pygmy cory owner, one should have them in groups of 8 or more in a single tank. If breeding, there should be an equal amount of males and females.

How Big Do Pygmy Corys Get?

Not big at all. Pygmy cory fish are ¾ of an inch on average. They would be essentially weightless in the palm of the hand.

Are Pygmy Corys Hardy?

Yes. Pygmy cory fish are pretty adaptable in 2-15 dkH carbonate hardness. They are freshwater fish that are oftentimes purchased from other breeders, making them perfectly tank-bred. An alkaline level somewhere around 8 is best for more balanced pH and calcium levels.

Do Pygmy Corys Need Sand?

No, but it’s preferable to their digging nature. Anything that does not damage their whiskers or fins would be best. It’s advised to use fine substrates like sand rather than pebbles. Another acceptable substrate would be very fine gravel, though not as praised as sand.

Do Pygmy Corys Need Sand?

Yes. The female pygmy cory does a methodic routine during reproduction. She holds up to 4 eggs between her pelvic fins. It only takes 30 seconds for the male cory to fertilize the eggs. The process is then repeated which can take a few days. By the end, the female pygmy cory could lay up to 100 eggs.

This is where caution needs to be applied for the genders of pygmy you use in one tank. Even if you’re deliberately breeding them, the time between reproduction and birth is less than two weeks. It’s even possible to get up to 200 fry in a week’s time.


The pygmy corydoras are hardy, peaceful, freshwater fish that will adapt well with several types of small fish in a wide range of alkaline levels. Their personalities thrive in a school of pygmy cory rather than by themselves. Breeders must beware of an increase in upkeep, but as long as clean filtered water and nutrient-dense food are provided, you are set to enjoy up to 3 years with this unique little catfish.

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