Blacktop corydoras (Corydoras acutus) care guide

Group

Freshwater fish

Other names

Black top cory

Family

Callichthyidae (armoured catfishes)

Origin

South America: the upper Amazon basin in northern Peru and Ecuador.

Water

freshwater

Maximum size

6.5 cm

Temperature

25–28°C

pH

6–8

Hardness

3–18 dGH (estimated)

Minimum tank

72 litres

Care level

intermediate

Temperament

peaceful

Care

A long-snouted cory, named after the dark patch on the top of the head and back. PlanetCatfish describes it as a peaceful shoaling fish that should be kept in a group of at least 6. A tank with a base of about 80 × 30 cm (around 72 litres) suits a group; this is our estimate from its adult size. Sand is the best substrate; avoid rough gravel, which damages the barbels. Give shade from overhanging rock, arching bogwood, tall or floating plants. It prefers warm water, about 25–28 °C, with pH 6–8. Keep the water clean with regular partial changes and avoid copper-based treatments. Females are larger and fuller-bodied, which is easiest to see from above; mature males are slimmer and have more pointed fins. Names: PlanetCatfish still lists it as Corydoras acutus. It is listed as Least Concern on the IUCN Red List (assessed 2020). Sources: PlanetCatfish (planetcatfish.com/corydorasacutus; species number not found). Checked October 2026.

Diet

An omnivore that forages over the bottom. PlanetCatfish notes it takes all prepared foods that reach the bottom (sinking tablets, granules and flakes) as well as live and frozen foods such as bloodworm, white worm and Daphnia. Feed it properly in its own right rather than relying on leftovers, and feed after lights-out if faster fish take everything first.

Breeding

Rarely bred: PlanetCatfish holds only a single breeding report. Spawning follows the usual Corydoras pattern: the pair takes up the "T-position", and the female holds a few eggs between her pelvic fins and sticks them to the glass, plants or décor, repeating this many times. Conditioning on live and frozen food, then a large water change with slightly cooler water, is the usual trigger. Remove the eggs or the adults, as the parents will eat the eggs, and raise the fry on microworm and newly hatched brine shrimp.

Compatibility and tank mates

A peaceful shoaling catfish for a community of small, calm fish: small tetras, rasboras, pencilfish, peaceful dwarf cichlids and other small catfish. Avoid large or boisterous fish that could bully or eat it, and fin-nippers. Choose tankmates that are happy in warm water.

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