Horseman's cory (Corydoras eques) care guide

Group
Freshwater fish
Other names
Horseman's corydoras, Osteogaster eques, CW043
Family
Callichthyidae (armoured catfishes)
Origin
Amazon River basin, Brazil; described from the Amazon near Codajás, Amazonas.
Water
freshwater
Maximum size
4.8 cm
Temperature
22.5–26°C
pH
6–8
Hardness
Soft to fairly hard, 2–16 dGH
Minimum tank
54 litres
Care level
beginner
Temperament
peaceful

Care

The horseman's cory is a peaceful, sociable fish. PlanetCatfish recommends a group of at least five; six or more of the one species is better, and a bigger group is bolder and more active. As a fish of under 5 cm kept in a group, a tank with a base of about 60 × 30 cm (roughly 54 litres) is a sensible minimum; this is our estimate, as the sources give no tank size. PlanetCatfish stresses a fine, smooth-grained sand floor. Use fine sand, or at least smooth rounded gravel kept very clean, so the fish can sift for food without wearing down their barbels. Add driftwood, plants and some shade, leaving an open patch of floor for foraging. Aim for about 22.5–26 °C, pH 6–8 and soft to fairly hard water (2–16 dGH), the ranges PlanetCatfish gives. Keep nitrate low with regular partial water changes and do not let waste build up in the substrate, as dirty conditions quickly lead to eroded barbels and infections. Corys handle salt and many medications (especially copper) poorly, so treat with care. Darting to the surface for a gulp of air now and then is normal: they breathe air through the gut. The pectoral-fin spines are sharp and can give a painful jab, so take care when netting and handling. The name comes from the large, saddle-shaped dark greenish-brown patch on the back, which looks like a rider's saddle. Females grow larger than males and are fuller and rounder in the body, which is easiest to see from above. The fish has the collector code CW043. Name note: after the 2024 split of Corydoras it is now classified as Osteogaster eques (the name PlanetCatfish and FishBase use), but it is still sold as "Corydoras eques". PlanetCatfish lists it as Not Evaluated, while FishBase gives an IUCN assessment of Least Concern (2020). Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=1351); FishBase (fishbase.se/summary/Corydoras-eques.html). Checked October 2026.

Diet

An omnivorous bottom forager. It takes most prepared foods that reach the floor, such as sinking tablets, granules and flake, and eagerly eats live and frozen bloodworm and Tubifex-type worms, which are also the best foods for bringing fish into breeding condition.

Breeding

Has been spawned in aquariums; PlanetCatfish holds several breeding reports. Condition a group, with more males than females, on live and frozen foods such as bloodworm. FishBase describes the usual cory method: the female holds 2–4 eggs between her pelvic fins while the male fertilises them, then sticks them to a surface, repeating until up to about 100 eggs are laid. A large water change with slightly cooler water is the usual trigger for corys. Remove the eggs or the adults afterwards, and raise the fry on microworm and newly hatched brine shrimp.

Compatibility and tank mates

Peaceful and best kept in a group of five or more. PlanetCatfish suggests similarly calm tank-mates such as small barbs and danios; small tetras, rasboras, dwarf cichlids and other peaceful catfish also suit it. Avoid large, aggressive or food-grabbing fish.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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