Pygmy corydoras (Corydoras pygmaeus) care guide

Group
Freshwater fish
Other names
Pygmy corydoras, Pygmy catfish
Family
Callichthyidae (armoured catfishes)
Origin
Rio Madeira basin in Brazil (Wikipedia also lists tributaries in Peru and Ecuador) – creeks, pools and flooded forest, sheltering in large groups among plants and roots.
Water
freshwater
Maximum size
2.1 cm
Temperature
22–26°C
pH
6.4–7.4
Hardness
Soft, up to 8 dGH
Minimum tank
41 litres
Care level
beginner
Temperament
peaceful

Care

One of the smallest catfish in the hobby, and one of the few corys that spends a lot of its time swimming in midwater rather than only on the bottom. It lives in big groups in the wild, so keep at least six and ideally ten or more – a large group is far more confident and moves about together like a little shoal. A tank with a base of 45 × 30 cm (around 41 litres) is enough for a good-sized group. Give it a soft sand substrate for foraging and to protect the barbels, plenty of plants, some driftwood or roots to shelter among, and gentle filtration – an air-driven sponge filter is ideal and won't suck up tiny fish. Keep the water clean and stable at 22–26 °C, pH about 6.4–7.4, and on the soft side. Like all corys it does not tolerate salt or many medications well, and a build-up of nitrate or dirty substrate causes problems, so stick to regular partial water changes. It can gulp air from the surface, which is normal behaviour. Pygmy corys are often confused with the tail-spot pygmy cory (Corydoras hastatus, now Gastrodermus hastatus). The pygmy has a dark band running from the tip of the snout along the whole side of the body onto the tail, while hastatus has no body stripe but a dark diamond-shaped spot on the tail base. The salt-and-pepper cory (C. habrosus) is another similar tiny species sold alongside them. Since the 2024 revision of Corydoras the valid name is Gastrodermus pygmaeus (used by PlanetCatfish and FishBase), but it is still sold almost everywhere as "Corydoras pygmaeus". It is widely available. FishBase lists it as Least Concern on the IUCN Red List; PlanetCatfish shows it as not evaluated. PlanetCatfish and FishBase both give a maximum of 2.1 cm standard length, which we use (Seriously Fish says 3 cm); females are the larger sex and look fuller from above. PlanetCatfish rates it hardy despite its size. Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=283); FishBase (fishbase.se/summary/Corydoras-pygmaeus.html); Seriously Fish (seriouslyfish.com/species/corydoras-pygmaeus/); Wikipedia (en.wikipedia.org/wiki/Corydoraspygmaeus). Checked October 2026.

Diet

An omnivore with a very small mouth, so everything must be bite-sized. Crumbled sinking wafers and flake are taken, but small live and frozen foods such as brine shrimp, sifted Daphnia, microworm and live blackworm keep it in the best condition and colour. Make sure some food gets past the other fish to the group.

Breeding

Breeds much like other corys. A small breeding tank of about 30 × 20 × 20 cm with a sand or fine gravel base, a sponge filter and some clumps of Java moss is enough; aim for about 24 °C and pH 6.5, with two males to each female. Females are noticeably rounder and broader, especially when full of eggs, and slightly larger. After conditioning on small live foods, a daily 50–70% water change with cooler water and extra aeration usually sets them off. The female carries a few eggs at a time between her pelvic fins and sticks them to the glass or plants, eventually laying up to around 100. Remove the adults or eggs afterwards. Eggs hatch in about 3–5 days; the tiny fry need infusoria at first, then microworm, vinegar eels, rotifers, small Daphnia or newly hatched brine shrimp. PlanetCatfish notes the adults rarely eat their eggs, and that it spawns in pairs or groups. Wikipedia notes they reach about 13 mm in 6–8 weeks and show adult colours within about a month.

Compatibility and tank mates

Very peaceful, but too small for a typical community tank: angelfish, gouramis, larger catfish and anything with a big mouth may eat it. Best kept on its own or with other tiny, gentle fish such as small South American characins (PlanetCatfish), small tetras, rasboras, pencilfish and other nano species, plus shrimps and snails. It also makes a good dither fish for Apistogramma and other dwarf cichlids in a roomy tank.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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