Peppered cory

Quick facts

Adult size

7 cm

Lifespan

can live up to 10 years

Tank zone

bottom

Temperament

peaceful

Difficulty

beginner

Schooling

recommended 6+ (critical minimum 4, thrives at 8+)

Water parameters

Temperature

18–26°C

pH

6.0 to 7.5

Hardness

2 to 15 dGH

Tank requirements

Minimum volume

80 L

Minimum length

75 cm

Flow

low

Lighting

moderate

Substrate

sand

Hiding spots

needed

Feeding

Diet: omnivore, feeds primarily at the bottom.

Sinking pellets, wafers, frozen bloodworm, frozen brine shrimp, blanched vegetables. They're heavy feeders relative to their size and need targeted bottom-feeding, not just whatever scraps float down from surface feeders. Drop sinking food directly onto the substrate after lights-out if competition from midwater fish is an issue. Live blackworms are an excellent food source and provide foraging enrichment. Feed daily.

Compatibility

• Same general profile as all Corydoras: peaceful, social, bottom-dwelling, harmless to everything. One of the original community tank catfish, kept since the early days of the tropical fish hobby.
• Groups of 6+ are necessary for natural behavior. Fewer than 4 and they hide more, eat less, and show stress marks (pale color, clamped fins).
• Tolerates cooler water than most tropical corys (18–24°C), which makes them one of the few corys suitable for unheated tanks in temperate climates. They do well with white cloud mountain minnows, paradise fish, and other cool-water species.
• Sand substrate is strongly recommended. Peppered corys dig constantly and sharp gravel abrades their barbels. Damaged barbels get infected and the fish can't forage properly.

Habitat

Native to the Rio de la Plata basin in southeastern South America: Argentina, Brazil, Paraguay, and Uruguay. Found in slow-moving rivers, streams, and floodplain pools over sandy and muddy substrates. This is a subtropical species, not a tropical one, which is why it tolerates cooler water (18–24°C) better than most corys in the hobby. The natural habitat experiences seasonal temperature swings that would stress species from the equatorial Amazon. The mottled olive-green and dark brown coloration with irregular dark blotches gives the species its common name. Males are smaller and slimmer; females are noticeably rounder when viewed from above. One of the first Corydoras species to reach the aquarium hobby (described by Valenciennes in 1840, imported to Europe in the late 1800s) and still one of the most widely kept. Tank-bred stock is universally available. An albino variant is common in stores.

Breeding

One of the easiest Corydoras to breed. The classic trigger works: a large water change with water 3–5°C cooler than the tank, simulating the onset of the rainy season. Condition the group with high-protein frozen food for 2 weeks beforehand. The T-position mating embrace is standard cory behavior: the female locks onto the male's barbels with her pelvic fins, receives sperm, and deposits 2-4 adhesive eggs on a flat surface (glass, broad leaves, filter intakes). The process repeats for hours, producing 100-300 eggs. Adults eat eggs, so either remove the adults or move the eggs (scrape gently with a razor blade) to a separate hatching container. Eggs hatch in 4-6 days at 22°C. Fry are larger than many cory fry and can eat baby brine shrimp from the start. Growth is steady; the cooler temperature means slightly slower development than tropical species. Peppered corys are a standard first-breeding project recommended to beginners because the species is tolerant, prolific, and the fry are hardy.

Common problems

Hardy and long-lived when kept properly. The cool-water preference is frequently ignored: peppered corys kept at 26–28°C with tropical community fish have shortened lifespans and are more susceptible to disease. The ideal range is 20–24°C. Barbel erosion on coarse substrate is the same issue as all Corydoras species. Bacterial infections (fin rot, body fungus) appear when water quality degrades; corys are in constant contact with the substrate and are exposed to accumulated organic waste. Regular substrate vacuuming is important. Red blotch disease (red patches on the belly or body) is a bacterial condition that appears in stressed corys; it responds to antibiotic treatment if caught early. Salt-sensitive; use half doses of any salt-based treatment.

Bioload

Bioload coefficient: 1.2 (medium cory; comparable to bronze cory).

Bioload coefficients are calibrated against the neon tetra as the anchor (1.0). See the methodology page for the formula and how each value was derived.

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size