Breeding Corydoras imitator

Breeding the long-nosed Corydoras imitator: soft blackwater conditions, cooler water-change trigger, glass and mop egg deposition, fry care.

Overview

Corydoras imitator (also placed in the genus Brochis) is a callichthyid catfish endemic to the upper Rio Negro basin in Amazonas state, Brazil, and southern Venezuela. Seriously Fish reports a maximum standard length of 55-65 mm. It is a long-nosed member of the adolfoi group, which carries an oblique dark bar along the dorsal surface, and it closely mimics the short-nosed C. adolfoi and related species, with which it forms mixed schools. Its natural habitat is pristine blackwater with tea-coloured water and a pH of 4.0-6.0.

Sexing

Females tend to grow larger, and sexually mature individuals are noticeably broader and deeper-bodied than males, especially when full of eggs.

Conditioning

Keep two or more males per female if possible. Condition the group well; spawning is attempted once females are visibly gravid.

Breeding Setup

Given the species' blackwater origin, soft, acidic water suits it; FishBase records a tolerance of pH 6.0-8.0 and 20-27 C with soft hardness (around 18-90 ppm). Provide glass, fine-leaved plants, or spawning mops as deposition sites, and keep fry over a thin sand layer.

Spawning Behaviour & Trigger

When females are gravid, perform a large 50-70% water change with cooler water and increase oxygenation and flow, repeating daily until the fish spawn.

Egg & Fry Care

Eggs are deposited on the aquarium glass, among fine-leaved vegetation, or within sunken spawning mops, the latter particularly recommended. Incubation is normally 3-4 days, and once fry have absorbed their yolk sacs they accept small live foods such as microworm and Artemia nauplii. Fry need excellent water quality.

Common Challenges

Seriously Fish notes the fry are not the easiest to raise, requiring excellent water quality; keeping them over a thin layer of sand appears to reduce ailments compared with a bare base.