Corydoras loxozonus Breeding Guide

How to breed Corydoras loxozonus, a Colombian cory that spawns in the classic T-position with eggs hatching in three to four days.

Overview

Corydoras loxozonus is a callichthyid catfish from the Rio Meta basin in Colombia, reaching a maximum standard length of about 5.5 cm. Like other Corydoras it is an egg-depositing spawner that uses the characteristic T-position, and it can be bred in a dedicated tank with patience.

Sexing

Females are noticeably rounder and broader-bodied than males, particularly when gravid, and tend to reach larger adult sizes. The most reliable way to compare body shape is to view the fish from above.

Conditioning

Condition the broodstock on a varied diet of live, frozen and dried foods. A spawning group is often arranged at a ratio of two males per female to improve fertilisation.

Breeding Setup

A breeding tank of around 18 x 12 x 12 inches with a sand or fine-gravel substrate is suitable. Eggs are quite robust and can usually be gently rolled up the glass with a finger if they need to be moved.

Spawning Behavior & Trigger

Spawning is typically triggered by a large 50-70% water change using cooler water, with increased oxygenation and flow, repeated daily until the fish respond. During spawning the pair adopts the T-position: the male grasps the female's barbels between his pectoral fin and body, and the female forms a basket with her pelvic fins into which the eggs are deposited and fertilised.

Egg & Fry Care

Eggs hatch in three to four days. Once the yolk sacs are absorbed, the fry accept microworm and brine shrimp nauplii as first foods.

Common Challenges

The main hurdles are conditioning fish into spawning condition, reproducing the cool water-change trigger reliably, and protecting eggs and fry. Maintaining clean water and a steady supply of small live foods supports fry growth.