Species Snapshot
- Common Names: Pygmy Corydoras, pygmy catfish
- Species Names: Corydoras pygmaeus
- Size: Up to 1 inch
- Lifespan: 3-5 years
- Native Distribution: South America
Known for their friendly temperaments and entertaining nighttime activity, corydoras are beloved in the aquarium hobby. These bottom-dwellers come in a range of patterns and sizes, the smallest being the aptly named pygmy corydoras (Corydoras pygmaeus).
If you’re looking for a peaceful addition to a nano tank or small freshwater aquarium, the pygmy corydoras is well worth considering. Here’s what you need to know about them.
Pygmy Corydoras Facts
Corydoras are freshwater catfish that are widely distributed throughout South America. Over 170 members of the Corydoras genus have been identified, many of which are endemic to very limited areas. Corydoras species range in size, body shape, and color but they share key anatomical characteristics—primarily their flat bellies, bony plates of armor, and sharp venomous spines.
Pygmy corydoras are among the smallest members of the genus. But how big do pygmy corydoras get? At maturity, this species gets up to 1 inch long with males being slightly smaller than females. Pygmy cories are silver in body with a black line running horizontally from snout to tail.
Like other corydoras species, pygmy corydoras inhabit the tropical inland waters of South America. They’re found throughout Peru—particularly in tributaries of the Nanay River—as well as tributaries of the Aguarico River in Ecuador and the Madeira River in western Brazil. Pygmy cories tend to prefer shallow, slow-moving waters with soft substrate and plenty of aquatic plants.
Setting Up a Pygmy Corydoras Tank
To keep your pygmy cories happy and healthy, it’s best to cultivate an aquarium environment that mimics their natural habitat. Like other corydoras species, pygmies prefer soft water with a slightly acidic to neutral pH level. This species in particular prefers cooler temperatures, however, between 72°F and 78°F.
The ideal parameters for a pygmy cory tank are:
- Temperature: 72°F to 78°F
- pH Level: 6.2 to 7.4
- KH: 6-10 dKH
- Tank Size: 10 gallons minimum
Though pygmy cories remain small, they prefer to be kept in schools with at least six of their own kind. They can be kept in a well-maintained 10-gallon tank, but larger tanks are usually better and tend to be easier to maintain. If you plan to keep other fish with your pygmy cories, be sure to size up your aquarium.
Filtration is important to keep the water quality in your tank high. Since corydoras come from slow-moving waters, low-flow filters like sponge filters are appropriate, though any filter with an adjustable output can work. It’s best to install an aquarium heater to keep the tank temperature stable and choose your lighting according to the type and number of live plants you have in the tank.
Pygmy corydoras are best kept in planted aquariums that provide plenty of places to hide. Like other corydoras, pygmy cories are nocturnal but they may also be active during the day. Dense planting helps these fish feel secure in their environment. Just be sure to leave some open space for swimming, as this species tends to occupy the middle as well as the lower level of an aquarium.
Before purchasing pygmy corydoras, make sure your tank is fully cycled and stable. Corydoras can be sensitive when transitioning into a new environment. Cories also can excrete a toxin when they’re stressed, so it’s important to make the transition as stress-free as possible to avoid losses. Always acclimate new corydoras but don’t draw out the process for too long.
Feeding Pygmy Corydoras
Pygmy corydoras feed primarily from the bottom of the aquarium where they’ll sift through the substrate to find leftover fish food and decaying organic matter to feed on. The best diet for pygmy cories is a nutritionally complete sinking wafer or pellet-style food formulated specifically for bottom feeders or catfish.
In addition to sinking pellets or wafers, you can supplement your pygmy corydoras’ diet with live or frozen foods. These fish will enjoy small foods like cyclops, daphnia, and baby brine shrimp but larger foods like bloodworms may be too difficult for them to eat.
Breeding Pygmy Corydoras
Many corydoras species breed readily in the home aquarium when the right conditions are present but pygmy cories are a little bit trickier. To breed pygmy cories, you’ll need a fully mature tank filled with live plants that have plenty of mulm and microfauna for the fry to feed on when they hatch. It’s also best to start with a colony of at least six corydoras to increase your chances of having both males and females in the group.
Pygmy corydoras are typically sold as juveniles, so it may take a few months for your new fish to be ready to breed. Keep an eye out and eventually you may see the females swell with eggs—you may also notice the males start to follow them around.
Unlike other corydoras species, pygmy cories don’t lay clusters of eggs—they deposit them singly in different locations around the tank. Fertilized eggs will hatch after 2-5 days, and the fry will grow quickly if properly fed. You’ll need to offer microscopic foods and perform frequent water changes to maintain high water quality as the fry matures.
Tips for Keeping Pygmy Corydoras
As previously mentioned, pygmy corydoras are most likely to thrive when kept in schools with others of their species. They can be kept with other corydoras species as well, provided the tank is large enough and food is plentiful.
In terms of other tank mates, pygmy corydoras will get along with just about any peaceful community fish. The important thing is to avoid keeping them with any fish big enough to eat them. Other nano species like chili rasboras, neon tetras, and otocinclus are a good fit. They also tend to do well with freshwater snails and dwarf shrimp.
When filling your aquarium, leave a little space at the top. Corydoras have gills to breathe underwater, but they also possess a labyrinth organ that enables them to take in air from the surface. You’ll see your cories darting up to the surface from time to time to breathe air, so make sure your tank has a tight-fitting lid just in case they jump.
Contact us today to start your perfect freshwater aquarium.