Sterba's Corydoras

Overview

• Sterba's Corydoras is a small armoured catfish from the upper Rio Guapore basin on the Brazil-Bolivia border, patterned with rows of fine white-to-cream spots over a dark head and body and set off by warm orange pectoral fins.
• Its defining practical trait is heat tolerance: it does well at ordinary corydoras temperatures but also stays comfortable up at the 28-30C (82-86F) that discus keepers run, which makes it the standard cory for warm-water tanks where the Bronze Corydoras would struggle.

• Virtually all fish sold today are tank-bred, hardy, and genuinely beginner-friendly, provided the basics are met: a shoal of six or more, soft sand, and food that actually reaches the bottom.
• It is often confused with Corydoras haraldschultzi, which reverses the pattern with dark spots on a pale ground; on sterbai the head is dark and the spots are pale.

Housing

• House a group of six in at least a 75-litre 20-gallon long, and give more floor space for larger groups, prioritising footprint over height because these fish live on the bottom.
• A soft sand substrate is non-negotiable, since sharp or coarse gravel erodes the sensory barbels they feed with.
• Keep the water at 24-28C (75-82F) with tolerance to 30C (86F), pH 6.0-7.6, soft to moderately hard (roughly 2-15 dGH), and low nitrate in a fully cycled tank.

• Furnish with driftwood, plants, leaf litter, and shaded resting spots, and leave open sand for foraging.
• They dash to the surface to gulp air, so keep an air gap beneath a tight-fitting lid.
• Warm water holds less oxygen, so at discus temperatures add extra surface agitation or an air stone.

Diet

• Sterba's Corydoras is an omnivore that must be fed deliberately, never left to survive on leftovers.
• Offer sinking wafers, pellets, and tablets, supplemented several times a week with frozen or live bloodworm, daphnia, and brine shrimp.

• Make sure food gets past faster mid-water fish; feeding after lights-out or dropping food at several spots helps the cories get their share.
• Quiet, slow starvation in busy community tanks is the most common way this species fails.
• Vacuum the sand regularly, because food rotting in the substrate drives the barbel infections that cost them the ability to find food.

Health

• The main preventable problems are barbel erosion and red blotch disease, both driven by sharp or dirty substrate and poor water quality.
• They are sensitive to salt and copper-based medications, so treat at reduced doses or choose catfish-safe alternatives.
• Watch barbel length, breathing rate, and skin condition, and quarantine all new arrivals.

• The orange pectoral spines lock outward under stress; they tangle hopelessly in fine nets and can give a mildly venomous prick, so move these fish with a rigid container or a bag rather than a net.
• Corydoras can also release a stress toxin in cramped transport bags, so bag them in generous water, a few fish per bag, for short journeys only.
• A well-kept sterbai commonly lives 5-10 years and can pass a decade with excellent care, so plan for a long-term resident.

Temperament

• This is a peaceful, day-active shoaling catfish that must be kept in a group of six or more of its own species.
• In proper numbers they forage in a loose pack, rest in piles, and show the characteristic corydoras eye-wink; kept alone or in pairs they hide and waste away.

• They are the classic bottom-dwellers for discus, cardinal tetras, rummy-nose tetras, and other warm-water community fish.
• Avoid large cichlids or anything big enough to try swallowing them, because the locking spines can lodge in a predator's throat and kill both fish.
• They bother no tankmate and are among the more willing corydoras to spawn in home aquaria, laying adhesive eggs on the glass after cool-water changes.

Is your enclosure big enough?

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Is this urgent?

In a fish tank the patient is usually the water. Test before you treat — dosing a healthy tank for a disease it does not have makes things worse.

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Never add a new fish to a tank that is not fully cycled, and never treat blind. A test kit is cheaper than the fish.

This is general guidance for a healthy adult, not a diagnosis. An exotics vet who knows your animal always overrides it — and the time to find one is before you need one.

What it really costs

Setup, monthly, first year and across a whole life, itemised and with the electricity worked out from the actual wattage. Published figures for the same animal disagree by a factor of four, so the calculator shows ranges rather than picking one.

Work out the cost of a sterba's corydoras