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Pygmy Corydoras
Corydoras pygmaeus
Also known as: pygmy cory, pigmy cories (three-line types)
A 3 cm mid-water schooling cory that swims in the water column, not just the bottom. Needs a large group of ten or more to behave naturally.
Pygmy Corydoras tank mates · 30L tank size hub
peaceful · beginner care
Sources & confidencehigh · partially verified · beginner: good
Checked against several solid care sources that mostly agree. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Planted nano and community tanks 30L or more with fine sand and a school of ten or more.
Avoid if: You can only source five or fewer fish, or your substrate is sharp.
Common mistakeExpecting pygmy cories to behave like classic bottom-dwellers is how keepers invent a midwater school with nowhere to swim. They school off the substrate and need tank height. Plan thirty-litre-plus planted height with six or more — a flat shallow tray wastes what makes Corydoras pygmaeus charming.
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **6** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Myth: pygmy corydoras are just miniature bottom cleaners that live on the sand like common cories. Reality: they school midwater and need height plus a real group — treat them as tiny midwater fish with sand, not unpaid substrate polishers.
- 2.Stocking three pygmies as a 'cleanup crew' in a 30L. They need a proper school of six before they leave the back corner.
- 3.Pairing with fish that out-feed them at the surface. A pygmy will starve under a fast gourami unless food sinks fast.
- 4.A nano-tank cory at 3 cm. Keep six or more. Unlike larger corys, pygmies spend half their day in midwater rather than the bottom. A solo pygmy hides in plants and rarely feeds.
About this species
- Corydoras Catfish60L min · same group, similar adult size
- Julii Corydoras60L min · same group, similar adult size
- Panda Corydoras60L min · same group, similar adult size
- Salt and pepper cory / dwarf cory60L min · same group, similar adult size
- Adolfoi cory80L min · same group, similar adult size
- Glass Catfish80L min · same fish family
- Peppered Corydoras80L min · same fish family
- Bronze corydoras100L min · same group, similar adult size
- Amano Shrimpalso beginner peaceful, similar tank size
- Assassin Snailalso beginner peaceful, similar tank size
- Beckford Pencilfishalso beginner peaceful, similar tank size
- Black Neon Tetraalso beginner peaceful, similar tank size
- Bloodfin tetraalso beginner peaceful, similar tank size
- Blue Dream Shrimpalso beginner peaceful, similar tank size
- Bloodfin tetra tank mateslists this fish among its safer mates
- Celestial Pearl Danio tank mateslists this fish as a safe and recommended mate
- Chili Rasbora tank matesnames this fish as a conditional pairing — read the pair page conditions
- Croaking gourami tank matesnames this fish as a conditional pairing — read the pair page conditions
- Dwarf pencilfish tank matesnames this fish as a conditional pairing — read the pair page conditions
- Ember Tetra tank mateslists this fish among its recommended pairings
- Golden dwarf cichlid (Nannacara) tank matesnames this fish as a conditional pairing — read the pair page conditions
- Green neon tetra tank mateslists this fish among its safer mates
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease78
- Peacefulness90
- Community fit72
- Small-tank fit100
- Hardiness76
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Prioritise 6+ of Pygmy Corydoras in 30L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Pygmy Corydoras
Usually safer (engine GOOD): Celestial Pearl Danio. Conditional (CAUTION — read the pair page before buying): Angelfish, Betta, Chili Rasbora, Otocinclus, Tiger Barb. Avoid (RISKY): Jack Dempsey, Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Pygmy Corydoras + Celestial Pearl Danio
Behaviour and temperament
Pygmy corydoras are peaceful micro schoolers that spend much of their time midwater in groups of six or more. They do not bully neighbours. Stress shows as hiding and scattering when under-grouped in a shallow tank with nowhere to school off the bottom.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- Six or more school midwater above sand and duck into plants when startled.
- Foraging both midwater and sand is normal ownership for this species.
- A scattered handful in a shallow tray means height and group size failed.
- Thin fish under hyper feeders usually mean competition stole every micro bite.
- Low listed malice toward peaceful nano neighbours.
- Large or aggressive fish are the usual failure modes — not pygmy spite.
- Grow the school and add height before rehoming for 'not acting like cories.'
- Remove boisterous midwater fish that outcompete them at every feed.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Pygmy corydoras are tiny omnivores that take micro sinking foods, crushed wafers, and fine frozen items in a school of six or more. They often feed midwater, so food that only hits the sand still helps — but surface flake alone leaves them thin. Offer small portions, keep height and plants, and never treat them as standard bottom-only cories.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- Hold 22 to 26 °C steadily on a real thermometer, not the dial on the heater.
- Aim for pH 6 to 7.5 and a hardness you can re-test in two weeks. A one-time strip in the shop car park is not a water test.
- Schooling species. Buy 6 or more from the same tank on the same day before adding any centrepiece fish.
- Tank volume meets or exceeds 30L published minimum for adults.
- You can stock at least 6 individuals (group welfare).
- Heater can hold 22–26°C without cooking cooler-water tank mates.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 30L minimum tank needs a filter rated for at least 120L/hr turnover and a heater to hold 22–26°C reliably.
Plant suggestions
Pygmy Corydoras does well in planted tanks. Plants compatible with 22–26°C and pH 6–7.5:
Research: partially verified · Confidence: high · 3 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Corydoras pygmaeus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Corydoras pygmaeus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Corydoras pygmaeus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
Evidence notes
- The Seriously Fish profile for the binomial in this record was successfully reached as the primary aquarium reference.
- FishBase contributes natural-range size and habitat context. Translate those numbers through your heater, your water report, and your tank footprint before stocking.
- Wikipedia is only cited if the article URL returned OK. Use it for orientation, not as the only care sheet for an import.
- All compatibility text reflects typical hobby experience and the Fishori model. Individual fish, shop stress, and the order tank mates are added in can still defy a single-paragraph label.
Common questions about Pygmy Corydoras
- How big do Pygmy Corydoras get?
- Pygmy Corydoras adults reach about 3 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Pygmy Corydoras need?
- 30L is the planning floor for adult swimming space and bioload. A 37L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Pygmy Corydoras aggressive?
- Pygmy corydoras are peaceful micro schoolers that spend much of their time midwater in groups of six or more. They do not bully neighbours. Stress shows as hiding and scattering when under-grouped in a shallow tank with nowhere to school off the bottom.
- Do Pygmy Corydoras need to be kept in a group?
- Schooling species — buy 6+ together. Smaller groups stress and lose colour.
- What is the most common mistake with Pygmy Corydoras?
- Expecting pygmy cories to behave like classic bottom-dwellers is how keepers invent a midwater school with nowhere to swim. They school off the substrate and need tank height. Plan thirty-litre-plus planted height with six or more — a flat shallow tray wastes what makes Corydoras pygmaeus charming.
- What fish can live with Pygmy Corydoras?
- The Pygmy Corydoras profile lists Celestial Pearl Danio among its safer pairings (engine-checked GOOD). Angelfish, Betta, Chili Rasbora, Otocinclus are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Jack Dempsey, Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.