Caresheet: Pygmy Cory

If you’re looking for a schooling fish with adorable looks that’s peaceful, fun to watch and can live in fairly small aquariums, look no further! Corydoras pygmaeus, better known as pygmy cory, has all these things and is therefore perfect for smaller community aquariums with 2-3 species. Keep reading for more info on how to keep and breed them!

Tank size 10 gallons (38l)
Temperament Peaceful
Diet Omnivore
Temperature 72-79 °F (22-26 °C)
pH 6.4-7.4
Length 1 inch (2.5 cm)

Name: Corydoras pygmaeus, pygmy cory, pygmy corydoras

Natural habitat: South America, mainly Rio Madeira.

Appearance: pygmy cories look just like most other Corydoras catfish, with the exception of the fact that they don’t grow bigger than 1 inch (2,5 cm). They are often mislabeled because they’re easily confused with Corydoras hastatus, another dwarf cory, but can be told apart by the stripe that runs down their entire body length. The difference between females and males is usually not too hard to tell, as females look much rounder, especially when viewed from above.

Área da UHE Santo Antonio - Rio Madeira

Rio Madeira, where these cories can be found in the wild. They mostly stick to the parts with overhanging vegetation.
Área da UHE Santo Antonio – Rio Madeira by dusantos_bh on Flickr.

Requirements: pygmy cories are one of the only Corydoras species that can be kept in smaller aquariums; a minimum of 10 gallons (38l) is usually recommended. Like all Corydoras species, pygmy cories should always be kept in bigger groups (at least 8). When the shoal is not big enough, they will often become skittish and stressed.
It is really important to use sand in the aquarium instead of gravel – when cories are kept on gravel for too long, their barbels will wear down, leaving them unable to properly search for food or behave naturally. In bad cases this can even lead to rot, which is very dangerous that close to the face of the fish! Cories that are kept on sand are also just much more fun to watch; I often see my pygmy cories burying their faces up to their eyes into the sand when they’re foraging!
When choosing tankmates for your pygmy cories, keep in mind that they are very small and peaceful and won’t do well with bigger, more aggressive fish. Good tankmates include shrimp, small tetras and dwarf cichlids.

Pygmy Corydoras do best when kept on sand.

Pygmy Corydoras do best when kept on sand.

Diet: contrary to popular belief, cories can’t thrive on just plant-based foods – they actually need a lot of meaty foods in their diet. Pygmy cories can be fed frozen foods (bloodworms, mosquito larvae, brine shrimp), catfish pellets, flake foods and the occasional algae pellet, but make sure the food is small enough to fit into their tiny mouths or they won’t be able to eat it! Disintegrating wafers like these come in handy here and make a great staple.

Behaviour: pygmy cories show very interesting behaviour and are fun to watch in the aquarium when they’re provided with a large enough shoal and plenty of hiding places. They shoal very well, only leaving the group to occasionally dart to the surface to gulp some air, which is a worrying sign in most fish species but completely normal in this case.

Contrary to most Corydoras, they don’t spend all of their time foraging on the bottom of the tank: they spend a lot more time in the middle water layer, which is something to be kept in mind when stocking the tank (two species in one water layer can look very messy!). During the time they do spend on the bottom of the tank, pygmy cories can often be observed digging through the sand very enthusiastically, occasionally even forgetting the rest of the shoal and wandering away. They never take their eyes off the other cories, though, and will quickly rejoin the group once they leave the bottom.

Breeding: breeding Corydoras pygmaeus is not considered very difficult, although raising the fry can be a bit challenging due to their size. Spawning can be triggered by doing water changes with slightly cooler water; when the female is ready, the eggs will be deposited on the tank glass. The parents should then be removed, as they will try to eat the eggs. It’s also possible to remove the eggs and raise them elsewhere by gently removing them from the glass with your finger. Some eggs will likely start to fungus after a few days; these should be removed as quickly as possible so the fungus doesn’t spread. Interestingly, it is mentioned on Seriously Fish that dwarf shrimp will spot and eat any eggs with fungus quite quickly, while leaving the healthy ones alone.
Once the fry hatch they should be fed with very tiny foods like infusoria or crushed flakes until they are big enough to accept bigger meals.

Let us out! :(

Let us out! :(

I have been keeping a group of Corydoras pygmaeus for a few months now; the group is a bit too small at the moment so they’re not as active as I’d like them to be, but you can clearly see the typical pygmy cory behaviour. They are incredibly fun to watch and I’d definitely recommend them to anyone who has a 10+ gallon aquarium and is looking for a peaceful schooling fish. These guys will even leave baby dwarf shrimp alone in most cases!
I can’t wait to get a few more and expand my own group – I’ll post some photos and videos when I do! :D

If you want to share your own experiences with pygmy cories or if you have any additional questions about keeping them, leave a comment or contact me! 

Happy cory-keeping!

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8 thoughts on “Caresheet: Pygmy Cory

  1. Yes they definitely love to venture upwards, quite amusing! I really like the mosquito rasboras as well. I know they’re typically blankwater fish though. Would the Cory mind the black water?

    • I don’t think they would! The water in the video in this caresheet looks at least slightly stained as well, and most sources claim these cories do well with a pretty low pH (I listed 6.4 here). Looking at caresheets of both species, I think their natural habitats are actually pretty similar! You could try adding indian almond leaves, they stain the water a very nice color and are also sometimes claimed to help prevent fungus.

  2. Hi!
    While I don’t have these little guys, I do have a dwarf relative of theirs, Corydoras habrosus. And was wondering how many i could comfortably keep in a 10 gallon tank by themselves, or how many with another small schooling fish (tetras, rasboras etc).

    • Corydoras habrosus are indeed very similar (almost identical) to Corydoras pygmaeus. A 10 gallon is a great place to start! I’d go for 5-8 cories depending on the amount of floor space. When keeping them with other small schooling fish, keep in mind that these cories don’t just stick to the bottom of the tank but also use the other water layers. Things could start looking a bit messy, but with a small school of cories and a small school of maybe rasboras (I love love love mosquito rasboras personally) I think you’re fine. If you don’t want them all using the same water layers, you could also look into shrimp, snails and small fish like otocinclus.
      Good luck! These cories are fantastic to keep :)

  3. Ah, your video is so sweet! I have a group of bronze corys in my Amazon tank who spawn a few times each spring, and I recently added some pandas to the mix.

    Your tank is so beautiful. I have a large light over my tank, but I want to replace it someday with the spotlight-type lights to make the water look more natural while still allowing for my plants to grow (the Amazon swords in my tank are monsters).

    Keep up the wonderful work. Your pets must love you!

    • The video isn’t mine, unfortunately! I wish that was my aquarium, haha, I agree that it looks absolutely gorgeous with the darker water and dimmed lights.
      How do you like the panda cories so far? I’m interested in getting some cories for another tank but I’m not sure whether I should go for pygmies or pandas!

    • Hi!
      Although I have never seen my dwarf crayfish show any signs of aggression, I would not recommend this combo. I’m not sure how cories sleep at night, and if the crays will try to hunt them when they do. You could try it, but I unfortunately can’t guarantee succes! Pygmy cories and rasboras would do great with shrimp, though, if you really want to keep inverts. Amano shrimp and cherry shrimp are great cleaners and very interesting to watch!

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