Corydoras wotroi (RARE)

One for people who already keep corydoras. Corydoras wotroi is a super rare South American species that rarely reaches the aquarium trade, described in 1979 and named after the Dutch research foundation that funded the expedition work behind it. If you have a tank of Bronze, Emerald and Peppered corys and want something your local shop will never have, this is that fish.

black dorsal fin with a line/mark running through the eye and a light yellowish mark just above the gill with small spots/peppering across the body

Behaviour is pure corydoras: peaceful, sociable, busy all day, and happiest in a group working its way across open sand. They rest in loose piles under wood, forage constantly, and dash to the surface periodically for a gulp of air. Nothing about the care is exotic — what is uncommon is the fish, not the requirements.

Care Snapshot

Scientific name	Corydoras wotroi
Family	Callichthyidae — armoured catfishes
Origin	[[tank-bred / wild-collected]] — South America
Adult size	[[adult size]] cm
Size on arrival	[[arrival size]] cm
Lifespan	5–8 years
Minimum tank	75 litres, minimum 60 cm length — floor area matters
Temperature	22–27 °C
pH	6.0–7.5
Hardness	2–15 dGH — soft to moderately hard preferred
Substrate	Fine smooth sand — non-negotiable
Diet	Omnivore — sinking foods, fed directly
Temperament	Peaceful, shoaling; keep 6+
Care level	Easy to moderate — given sand and proper feeding
Swimming zone	Bottom; surfaces periodically to gulp air

Setting Up For It

• Open sand, and plenty of it. Floor area is what counts for a bottom-dwelling shoal, not water volume. Leave broad clear stretches rather than carpeting the whole base with plants.
• Keep the surface accessible. Corydoras breathe atmospheric air through the gut and must be able to reach the surface. Dashing up and back down is normal behaviour, not distress.
• Shade, wood and leaf litter. Uncommon species settle in faster with cover and a dimmer light. Catappa leaves and driftwood also soften the water slightly, which suits this group.
• Siphon the sand at every water change. Food and waste settle exactly where these fish feed. Dirty substrate is the second route to barbel damage after sharp gravel.
• Gentle to moderate flow, with good oxygenation. Not strong swimmers, but they want clean, well-moved water.
• Keep six or more, and consider a species tank. Rarely traded corydoras are worth keeping as a single-species group rather than scattered through a community — easier to feed properly, easier to observe, and the only realistic way to attempt breeding.

Tank Mates

Adult dwarf shrimp are generally safe alongside them, though shrimplets on open sand may be taken.

Feeding — They Are Not A Cleanup Crew

The most persistent myth about corydoras is that they live on leftovers. They do not. A group fed only on what drifts past the tetras will decline slowly over months, and because they are hardy fish it takes a long time to become obvious. Feed them deliberately, every day, with food that reaches the bottom.

From the AQA range, use a sinking wafer or small granule as the daily staple, with frozen bloodworm, brine shrimp or daphnia two or three times a week. Feed after the tank lights go off if faster fish are clearing everything first — these catfish are perfectly happy feeding in the dark.

Watch body condition from above. A healthy cory is rounded across the shoulders; a thinning one narrows noticeably behind the head.

Sexing & Breeding

Females are larger and distinctly broader when viewed from above, particularly when in condition. Males are smaller and slimmer with a more pointed outline. The difference is clear only in mature fish and is best judged looking down into the tank rather than through the glass.

Breeding follows the corydoras pattern — condition heavily on live and frozen food, then trigger spawning with a large water change using cooler water. Eggs are pressed onto glass, filter surfaces or broad leaves and must be separated from the adults. Rarely traded species like this one are worth the attempt: captive-bred stock of uncommon corydoras is genuinely scarce, and a hobbyist who establishes a breeding group is adding something the trade does not otherwise have.

Keeping It In Indian Conditions

• Room temperature works across most of India for most of the year, so a heater is needed only for northern and hill-station winters.
• Watch the summer ceiling. Above 27 °C, oxygen falls and these are bottom fish in the least oxygenated part of the tank. Increase surface agitation and run a fan across the water through April and May.
• Softer water suits this group. Hard alkaline tap water is workable, but catappa leaves and driftwood bring conditions closer to what the species comes from, and help a newly imported group settle.
• Substrate is the thing to get right locally. Most Indian aquarium shops sell sharp crushed gravel, which is precisely what damages barbels. Fine river sand is cheap and widely available — rinse it thoroughly until the water runs clear.