Bronze Corydoras

Looks how to spot one

Armoured catfish (bony plates, no scales)

A small, stocky bottom-dweller covered in overlapping bony plates rather than ordinary scales, with short whisker-like barbels around the mouth for feeling through sand. The body shows a metallic green-bronze sheen over a pinkish or yellowish base, a pale belly and a bluish-grey head and back, often with a brownish-orange patch on the head just in front of the dorsal fin. The dorsal and pectoral fins carry stiff, sharp spines, so a soft net is the gentlest way to move one. Females grow a little larger and rounder than males.2134

Personality what they are like

Calm, gentle and very social. Bronze corys spend the day snuffling through the substrate in little groups and mix well with other peaceful fish. In the wild they gather in schools of 20 to 30, and in a tank they are happiest and most confident with plenty of their own kind.312

Daily activity how busy a day looks

Active bottom foragers that are busiest around dusk and at night. They need open floor space to roam and sift, and they regularly dart to the surface for a gulp of air, so the water surface must stay accessible.13

Grooming and care the hands-on bits

Water: 20 to 28 C (sources vary; about 21 to 27 C is a comfortable middle), pH 6.0 to 8.0, hardness roughly 2 to 15 dGH (wider ranges quoted). Keep the substrate clean with regular partial water changes, since these fish spend their lives on the bottom and probe it with their barbels. Use a net rather than hands because of the sharp fin spines.123

Home where they are happiest

An aquarium with a footprint of at least about 80 x 30 cm (roughly 70 litres) suits a group; FishBase gives 60 cm as a bare minimum length. Fine sand is the ideal floor, or smooth rounded gravel kept clean. Add some plants, wood or other cover for shelter. In nature they live in quiet, shallow, soft-bottomed waters, and sometimes in flowing streams.31

Food basics what goes in the bowl

Omnivore. Wild fish eat worms, small bottom-living crustaceans, insects and plant matter. In the aquarium offer sinking pellets or wafers plus frozen or live foods such as bloodworm, and make sure food actually reaches the bottom. They should be fed deliberately, not left to live on leftovers from other fish.132

Company who they like around

Strongly social. Keep at least 4 to 6, and ideally a larger group of 5 or more of the same species. They get along with most small, peaceful tankmates.312

The story where it all began

The American zoologist Theodore Gill first described the fish in 1858 from a specimen caught in Trinidad, naming it Hoplosoma aeneum. It later spent well over a century as Corydoras aeneus, and several other names given to local forms (such as C. macrosteus, C. microps, C. schultzei and C. venezuelanus) were folded into it as synonyms. Its huge range has long made scientists suspect it is really a group of look-alike species. A genome-based study published in 2025 split up the big genus Corydoras and placed the bronze cory in the revived genus Osteogaster, whose name means 'bony belly'. In the aquarium world it has been a favourite for decades: it is bred and shipped worldwide in large numbers each year, and farmed albino and long-finned forms are common.235

Recognised by the official bits

IUCN Red List

Assessed as Least Concern (7 November 2018)1

Taxonomy

Moved from Corydoras to the revalidated genus Osteogaster after a phylogenomic study by Dias, Tencatt, Roxo and colleagues (Zoological Journal of the Linnean Society, 2025); the wild 'species' is regarded as a complex of similar fish awaiting review5

Family

Callichthyidae (armoured catfishes)3