Breeding Corydoras polystictus

Breeding Corydoras polystictus: sexing, ~75 F / neutral pH setup, cooler water-change trigger, glass egg deposition and fry care.

Overview

Corydoras polystictus is a small callichthyid catfish found in the upper Rio Paraguay in the Brazilian state of Mato Grosso. Seriously Fish gives a maximum standard length of about 5 cm (2 inches).

Sexing

Females are noticeably rounder and broader-bodied than males, especially when full of eggs.

Conditioning

Condition the group on a varied diet of live, frozen, and dried foods. A ratio of two males per female is recommended.

Breeding Setup

A breeding tank of about 18 x 12 x 12 inches with a bare bottom, sand, or fine gravel is suitable, along with air-powered sponge filtration and clumps of java moss. Reported spawning conditions are a temperature of around 75 F and a pH of around neutral.

Spawning Behaviour & Trigger

Perform a large 50-70% water change with cooler water and increase oxygenation and flow, repeating daily until the fish spawn. The fish usually lay their eggs on the tank glass, often in an area where water flow is quite high.

Egg & Fry Care

The eggs hatch in 3-5 days. Once the fry have used up their yolk sacs, they accept microworm and brine shrimp (Artemia) nauplii as first foods.

Common Challenges

As with related species, positioning egg-deposition surfaces near strong flow and maintaining excellent water quality for the fry are the main keys to success.