Species · Aquatic pet

Corydoras

Corydoras spp.

Small armoured catfish of South American streams, kept in shoals along the bottom of community tanks everywhere.

Corys are the community tank’s good citizens: peaceful, industrious, comically busy little armoured catfish that patrol the bottom in a group. The group is the point — a shoal of six is the entry ticket, and more is visibly better, because a lone cory is a subdued shadow of the animal. The other kindness is under their chins: those delicate barbels want soft sand, not sharp gravel, and they want actual sinking food, not the hope of leftovers.

At a glance

Lifespan: 5–12 years
Adult size: 4–7 cm
Minimum tank: 80 L for a shoal
Water: Tropical fresh
Weekly upkeep: Weekly partial water change
Diet: Sinking wafers and pellets — fed on purpose
Company: Six minimum, always
With children: Watch, don’t touch
Tankmates: Peaceful community; nothing that eats them

Varieties · 4 listed

Dozens of species share the same keeping: bronze and albino (the same species), pandas, peppers. Shoal one species properly rather than collecting singles.

Bronze
Albino
Panda
Peppered

Right for you if

A proper shoal — six or more of one species — fits your tank and budget.
Sand or smooth fine substrate is in place or you will change it.
You will feed the bottom directly and watch that it arrives.
Busy, peaceful, low-drama fish are your idea of a good tank.

Wrong for you if

The plan is one or two “to clean up” — wrong animal, wrong number, wrong job.
Sharp gravel is staying.
The tank’s other residents feed so fast nothing reaches the floor.
The tank is tiny; a shoal needs floor space more than volume.

Welfare and sourcing — read this part

Most fish disease follows stress, poor water quality, overcrowding and skipped quarantine.¹ For a shoaling species, being kept in too-small numbers is a stressor you buy at the counter — six is the minimum kindness.
Check barbels before buying: full, intact whiskers around the mouth. Eroded stubs mean the shop’s substrate or water has already done damage.
Buy the shoal from one tank in one visit, quarantine together, add together — a settled group settles faster than serial introductions.

Sources

Disorders and Diseases of Fish. MSD Veterinary Manual 2026. Accessed 2026-09-05. International MSD Veterinary Manual Many of the disorders and diseases that occur in fish are the result of stress, poor water quality, overcrowding, and failure to quarantine. New tank syndrome is ammonia accumulating when fish are added before the biological filter works, typically in the first one to three weeks. Ich (white spot) is a common protozoal infestation whose fast reproduction is what makes it deadly.

Every source here was checked, not recalled. Where this page makes a health statement and no source appears against it, that is not an oversight we have hidden — it means the claim is not yet sourced, and the build reports how many are in that state.

Availability, registration and keeping requirements differ from place to place. Check the rules where you live before you commit to any animal — we describe animals, not law.