Sterbai cory

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: sand.

Behavior

Plant interaction: plant safe.

Feeding

Sinking pellets, sinking wafers, frozen bloodworm, and brine shrimp. Sand substrate is mandatory for all corydoras species; sharp gravel damages the barbels. Feed in the evening when corys are most active. Like all corys, sterbai are slow eaters that need food to reach the bottom. In a tank with aggressive midwater feeders, use sinking food that drops quickly. Corys supplement their diet by sifting microorganisms from the sand, which is fascinating to watch but not sufficient on its own.

Compatibility

• Peaceful community fish. Safe with everything that won't eat it.
• The warm-water tolerance makes it the go-to cory for discus, rams, and other species needing 27–30°C.
• Keep in groups of 6+ of the same species. Sterbai corys do not school with other corydoras species.
• Safe with shrimp and snails.
• Avoid aggressive cichlids or large fish that might bully bottom-dwellers.

Origin and habitat

Native to the Rio Guaporé (also called Río Iténez), which forms part of the border between Bolivia and Brazil; part of the larger Mamoré/Madeira system within the Amazon drainage. The Guaporé flows over ancient rock of the Brazilian Shield, producing soft, clear water that becomes tannin-stained blackwater from decomposing organic material. Inhabits small tributaries, creeks, pools, and areas of flooded forest with sandy substrates. Described by Knaack in 1962; recently reclassified as Hoplisoma sterbai following a 2024 phylogenetic revision by Dias et al., though most of the hobby still uses Corydoras sterbai. Named after Günter Sterba. White spots on a dark brown to black body, with bright orange pectoral and pelvic fins; occasionally confused with C. haraldschultzi, which has the reverse pattern (black dots on a white background) on the head. Grows to about 6.5–8 cm including tail. Prefers warmer water than most corydoras, thriving at 25-29°C (77-84°F), making it the standard corydoras choice for discus tanks and other warm-water setups where species like peppered or panda corys would suffer. Albino and black color forms are available. Virtually all trade specimens are commercially farmed; wild-caught fish are rarely imported.

Breeding

Same as other corydoras: triggered by large cool water changes (drop temperature 2–3°C). T-position spawning where the female cups eggs in her pelvic fins. Eggs are deposited on glass, plant leaves, and smooth surfaces. 50-150 eggs per spawning event. Parents don't eat eggs reliably (unlike some corys), which means eggs often survive in a community tank if there aren't dedicated egg-eaters present. Eggs hatch in 3-5 days at 26°C. Fry are easy to raise on crushed dry food and baby brine shrimp.

Common problems

Barbel erosion from rough substrate. Use sand, not gravel. Ich from transport stress is common in new purchases. Sterbai corys are sensitive to salt and copper-based medications; use half doses or alternative treatments. Like all corys, they gulp air at the surface occasionally; this is normal and not a sign of poor oxygenation unless it happens every few minutes. Overfeeding leads to fouled sand and bacterial growth in the substrate, which can cause barbel infections.

Bioload

Further reading

• Stocking ideas by tank size