Breeding Corydoras concolor (Slate Cory)

Breeding guide for Corydoras concolor: sexing by the male's extended dorsal fin, conditioning, spawning trigger and fry care.

Overview

Corydoras concolor is an armoured catfish (family Callichthyidae) restricted to parts of the Orinoco river system in western Venezuela, reaching about 55–60 mm standard length. It is an egg-depositor that spawns in the Corydoras T-position.

Sexing

Mature males develop an extended dorsal fin. Females tend to grow larger, and sexually mature individuals are noticeably rounder and broader-bodied than males, especially when gravid.

Conditioning

Feed the group well on a varied diet of small live and frozen foods until the females are visibly full of eggs. Good condition and clean water are the foundation of a successful spawn.

Breeding Setup

• Temperature: 20–26 °C
• pH: 5.5–7.0
• Hardness: 18–143 ppm
• Provide aquarium glass and fine-leaved vegetation as egg deposition sites

Spawning Behavior & Trigger

Eggs are normally deposited on the aquarium glass or among fine-leaved vegetation. The female holds the sticky eggs between her pelvic fins, fertilises them in the T-position with a male, then attaches them to the chosen surface.

Egg & Fry Care

After spawning, eggs can remain in the original tank or be moved to a separate container with identical water chemistry and strong aeration. Incubation is normally 3–4 days; once the fry have absorbed their yolk sacs they accept small live foods such as microworm and Artemia nauplii. Fry are less susceptible to ailments over a thin layer of sand than in a bare-bottomed arrangement.

Common Challenges

To prevent egg fungus, breeders typically add methylene blue or alder cones to the egg container.