Catfish & plecos · Gastrodermus pygmaeus

Pygmy corydoras care guide

Also called: Pygmy cory, Pygmy catfish, Pygmy cory catfish, Corydoras pygmaeus

The pygmy corydoras is one of the smallest corys at about 1 in (2.5 cm). Unlike most corys, it hovers in midwater in a tight shoal. It suits planted nano tanks with tiny, peaceful fish and needs a group of 10 or more.

Pygmy corydoras need a tank of at least 10 gallons (38 L), a group of 10 or more, and water at 22–26°C (72–79°F) with a pH of 6.4–7.4. They grow to about 2.5 cm (1 in) and are peaceful.

Plan a tank with pygmy corydorasSee all tank mates

Pygmy corydoras quick facts

Scientific nameGastrodermus pygmaeus
FamilyCallichthyidae
OriginRio Madeira basin in Brazil, with reports from Peru and Ecuador
Adult size2.5 cm (1 in)
Minimum tank10 gallons (38 L)
Temperature22–26°C (72–79°F)
pH6.4–7.4
Hardness (GH)2–10 dGH
Group size10 or more (shoaling fish)
TemperamentPeaceful
Swims atMiddle
DietOmnivore
Care levelModerate
Lifespan3–4 years
Safe with shrimp?Mostly (eats baby shrimp)
Safe with plants?Yes
  • Needs sand or smooth, fine gravel to protect its barbels and belly.

Tank setup

A 10 gallon (38 L) tank is a sensible minimum for a group of 10, and a longer tank gives the shoal more room to swim. Plant it densely, add wood and broad leaves for them to perch on, and keep the light dim or use floating plants. Use fine sand, a gentle sponge filter or covered intake, and a lid with a small air gap.

How many pygmy corydoras in a tank?

The smallest common tank that suits pygmy corydoras is a 10 gallon. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.

TankPygmy corydoras (alone)
3 gallonToo small
5 gallonToo small
10 gallon10–27
15 gallon10–41
20 gallon10–55
20 gallon long10–55
29 gallon10–79
40 gallon10–110
55 gallon10–151
75 gallon10–206
125 gallon10–344

What you need for pygmy corydoras

Sized for a 10 gallon tank, the smallest common size that suits a group of 10 pygmy corydoras. For a different tank or a mix of fish, use the stocking calculator for a list sized to your plan.

Tank and equipment

Food and extras for pygmy corydoras

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Water parameters

Keep them at 22–26 °C (72–79 °F), pH 6.4–7.4 and soft to moderately hard water, ideally 2–10 dGH. They are more sensitive to nitrate and new-tank swings than larger corys, so add them only to a mature, cycled tank. Frequent partial water changes keep nitrate low.

Best tank mates for pygmy corydoras

These popular species share pygmy corydoras' water needs and temperament. See the full list of 87 good matches.

Avoid keeping pygmy corydoras with

  • Angelfish: Angelfish can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.
  • Common goldfish: Common goldfish can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.
  • Fancy goldfish: Fancy goldfish can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.
  • Oscar: Oscar can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.
  • Bala shark: Bala shark can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.
  • Blood parrot cichlid: Blood parrot cichlid can eat pygmy corydoras: they're small enough to fit in its mouth once it's grown.

Feeding

Their mouths are tiny, so feed crushed flakes, micro pellets and small frozen foods such as daphnia, cyclops and baby brine shrimp. Regular bloodworms are often too big. They eat slowly, so feed where they gather and make sure faster fish do not take everything.

Behavior

Peaceful and shy, they shoal in midwater and rest on leaves, wood and the glass, darting to the surface now and then for air. Keep them with other tiny, calm fish such as ember tetras, chili rasboras and celestial pearl danios. Larger fish can bully or eat them, but adult dwarf shrimp are safe with them.

Breeding

Pygmy corys spawn in mature, planted tanks, often after a cooler water change, with about two males per female. Females stick single tiny eggs on glass, moss or roots, and they hatch in about 2–5 days. The fry are very small and need infusoria or similar first foods before moving on to baby brine shrimp.

Tips from experienced keepers

  • Keep 10 or more. Small groups hide, while a big shoal hovers in the open and is far more fun to watch.
  • Feed tiny foods. Most standard wafers and bloodworms are too large for them to eat easily.
  • Cover filter intakes with a sponge so these tiny fish and their fry cannot be pulled in.
  • A great match for shrimp tanks. Adult dwarf shrimp are safe, though a few shrimplets may be eaten.
  • Add them only to a mature tank. They handle nitrate and new-tank swings worse than bigger corys.

Frequently asked questions

How many pygmy corydoras should be kept together?

Aim for 10 or more. In small groups they hide and stay stressed, while a larger shoal swims openly in midwater.

Can pygmy corydoras live with shrimp?

Yes. They are one of the safest fish for a shrimp tank. They leave adult dwarf shrimp alone, though they may eat a few newborn shrimplets.

Can pygmy corydoras live in a 5 gallon tank?

A 10 gallon (38 L) tank is a better minimum. A 5 gallon can hold only a few, and a group that small rarely feels secure.

Is the pygmy cory still a Corydoras?

Recent research moved it to the genus Gastrodermus, so newer labels may say Gastrodermus pygmaeus. It is the same fish sold for years as Corydoras pygmaeus.

Sources

We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.