Emerald Corydoras Breeding Guide

How to breed the emerald corydoras (Brochis / Corydoras splendens): sexing, conditioning a group, bottom-sitting spawning, and rearing the fry.

Overview

The emerald corydoras (Brochis splendens, also placed in Corydoras) is the largest commonly kept Corydoras relative, reaching about 7.5 cm, and is native to the upper Amazon basin including the Ucayali River and waters of Peru, Brazil, Colombia and Ecuador. It is an egg-laying, T-position-style spawner that pastes eggs onto surfaces.

Sexing

Females are larger and more robust than males and have a more pinkish belly, while males show a more yellowish underside; mature females are noticeably rounder and higher-bodied.

Conditioning

Condition a breeding group on live foods; a setup of about three males to two females has been used successfully. Live worms are especially valued for bringing the fish into condition.

Breeding Setup

House the group in clean water within the species' general range of about 22-28 C (72-82 F), pH 5.8-8.0 and a hardness of 2-30 dGH. As with related catfish, a cool, oxygen-rich water change is commonly used to encourage spawning, with plants and surfaces available for egg deposition.

Spawning Behavior & Trigger

Unlike many similar species, the pair spawns while sitting on the bottom rather than while swimming. The female collects eggs in her pelvic-fin basket and pastes them individually onto plants and surfaces, with eggs laid close to the water surface that are easy to relocate for rearing.

Egg & Fry Care

Eggs hatch in about four days, and the fry become free-swimming roughly two days later. Parents do not usually consume the eggs immediately, but moving the eggs to a separate rearing container with matching water is the safest option; feed the fry small live and powdered foods.

Common Challenges

Because this is a larger Corydoras relative, mature breeders and a generous tank are needed for good condition. As with other corys, fungus on eggs and predation are the main risks, which is why eggs are commonly reared separately.