Not furry, but we like them anyway.
Pygmy Corydoras
Gastrodermus pygmaeus (Knaack, 1966); long known as Corydoras pygmaeus
Also called Pygmy cory, Pygmy catfish, Corydoras pygmaeus (former name)
From Rio Madeira basin in Brazil, in small tributaries, creeks and flooded forest; also reported from tributaries of the Nanay River in Peru and the Aguarico River in Ecuador.123
A friendly guide, not veterinary advice. For anything about your pet's health, ask your vet.
At a glance the quick version
Looks how to spot one
Armoured catfish (bony plates, no scales)
One of the tiniest catfish in the hobby. The slim, silvery body carries an unbroken black stripe along the middle of each side, a second thin line lower down toward the tail, and a dusky grey back. Females are a little larger and plumper than males. Newly hatched babies have vertical bars that fade within about a month.21
Personality what they are like
Very gentle and a little timid. Unlike most corys it often hovers and swims in loose shoals in the middle of the tank, not just on the floor. It is easily intimidated by large or boisterous tankmates, so it suits calm setups with other small fish.12
Daily activity how busy a day looks
Active and constantly on the move, mixing midwater shoaling with grazing on the bottom.12
Grooming and care the hands-on bits
Keep the water clean and stable with regular partial changes. A fine sand or smooth substrate suits its small barbels.1
Home where they are happiest
Minimum footprint of about 45 x 30 cm (around 41 litres) for a group. Water 22 to 26 C, pH about 6.0 to 8.0, soft water preferred (below about 8 dGH, though FishBase lists 2 to 25 dH). Planted tanks with open swimming space suit it well.13
Food basics what goes in the bowl
Small dried foods, crushed if needed, plus tiny live or frozen foods such as daphnia and baby brine shrimp, which also help bring out its colour.1
Company who they like around
A true shoaling fish: keep at least six, ideally ten or more.12
The story where it all began
The German aquarist Joachim Knaack described this species in 1966. For years it was often mixed up with the similar dwarf corydoras. In 2025 it was moved into the resurrected genus Gastrodermus.24
Fun facts for the dinner table
- 1
It is one of the smallest corydoras, with adults often only around 2 to 2.5 cm long.2
- 2
It is told apart from the look-alike dwarf corydoras by its full-length side stripe; the dwarf cory has a diamond-shaped spot at the tail instead.1
- 3
Baby pygmy corys hatch with vertical stripes that disappear within about a month.2
- 4
A female lays roughly 100 eggs per breeding cycle, carrying a few at a time between her pelvic fins.2
Recognised by the official bits
- IUCN Red List
- Least Concern (assessed 15 October 2020)3
- Taxonomy
- Placed in the resurrected genus Gastrodermus by the 2025 phylogenomic study of Dias, Tencatt, Roxo and colleagues4
- Family
- Callichthyidae (armoured catfishes), subfamily Corydoradinae2
The care rhythm Furry Diary remembers it for you
A typical home-care rhythm for a Pygmy Corydoras. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- FeedingSmall amounts once or twice a dayevery day
- Temperature checkevery day
- Water changeAbout 25% of the waterevery week
- Water testevery week
- Glass cleanevery week
- Filter rinseRinse in old tank water, never tap waterevery month
Owner questions the things everyone asks
How often should I feed my Pygmy Corydoras?
Feed your Pygmy Corydoras small amounts once or twice a day. Furry Diary's starting plan is to feed daily, and you can adjust based on how much they eat in a couple of minutes.1 Furry Diary plan
What does a Pygmy Corydoras eat, and what should it never eat?
They eat small dried foods, crushed if needed, plus tiny live or frozen foods like daphnia and baby brine shrimp. Avoid large or hard foods that could harm their tiny mouths, and never feed anything not meant for fish.1
How much space does a Pygmy Corydoras need?
A group needs a tank with a minimum footprint of about 45 x 30 cm, which is around 41 litres. This gives them room to shoal and swim comfortably.13
What temperature, light or water does a Pygmy Corydoras need?
Keep water temperature between 22 and 26°C, pH around 6.0 to 8.0, and soft water is preferred (below about 8 dGH). Planted tanks with open swimming space suit them well.13
How often should I clean a Pygmy Corydoras's home?
Furry Diary's starting plan suggests a weekly 25% water change, weekly glass cleaning, and a monthly filter rinse in old tank water. Regular cleaning keeps the water stable and healthy. Furry Diary plan
Can a Pygmy Corydoras live with others?
Yes, they are very gentle and a little timid, so they do best with calm, small tankmates. They are true shoaling fish and should be kept in groups of at least six, ideally ten or more.12
How long does a Pygmy Corydoras live?
Lifespan varies depending on care and environment. For specific details, ask a good breeder or an exotic-pet vet.
Can I handle a Pygmy Corydoras?
It's best not to handle them as they are delicate and can be stressed. Always use a soft net if you need to move them, and keep handling to a minimum.1
Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Furry Diary's own starting care plan. A friendly guide, not a vet's advice.
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- Seriously Fish: Corydoras pygmaeus seriouslyfish.comused for care, size, behaviour, identification
- Wikipedia: Pygmy corydoras en.wikipedia.orgused for description, colour, distribution, history, breeding
- FishBase: Gastrodermus pygmaeus fishbase.seused for valid name, length, water parameters, IUCN status
- Wikipedia: Gastrodermus en.wikipedia.orgused for 2025 genus revalidation
- VCA Animal Hospitals: Feeding times and frequency for your dog vcahospitals.comused for owner questions
- ASPCA: Dog grooming tips aspca.orgused for owner questions
- ASPCA: Cat grooming tips aspca.orgused for owner questions
- ASPCA: People foods to avoid feeding your pets aspca.orgused for owner questions
- RSPCA: What to feed your rabbit rspca.org.ukused for owner questions
Checked 2026-09-30. Text is written in our own words from these sources.