Golden Wonder Killifish Breeding Guide

How to breed Aplocheilus lineatus, a non-annual surface plant-spawner: sexing, conditioning, mop or plant spawning, water egg incubation and rearing fry.

Overview

Aplocheilus lineatus, the striped panchax, is a surface-dwelling killifish from fresh and brackish waters of India and Sri Lanka, found in streams, rivers, swamps and paddy fields. The aquarium variant with more yellowish coloration is known as the golden wonder killifish. It is a non-annual plant-spawner that deposits its eggs in vegetation and inhabits permanent water rather than seasonal pools.

Sexing

The species grows to about 10 cm, with males typically around 7 cm. As is general among plant-spawning killifish, males are the larger, more colourful and longer-finned sex, with females plainer and rounder-bodied. It is a surface predator feeding in the wild on insects, crustaceans and even small fishes, and a parietal eye lets it watch the surface above.

Conditioning

Condition females separately with generous feedings of live and other high-quality foods for about a week before introducing a male; this preparation typically results in spawning commencing quickly once the pair is together. A tight-fitting lid is essential as the species can jump very well.

Breeding Setup

Use a well-planted breeding tank with a surface egg-deposition medium such as spawning mops or fine-leaved plants, where this plant-spawner attaches its eggs. Including plant matter from an established tank in any separate rearing container provides microorganisms for the smallest fry.

Spawning Behavior & Trigger

In the typical plant-spawner spawning act the male approaches the female from the rear and side, aligns his body alongside hers, and with the pair in an S-shaped formation presses her against the plant. Once conditioned, spawning quickly commences and continues more or less until she is depleted, generally within two to eight hours.

Egg & Fry Care

Eggs require water storage; the egg-storage water should be changed daily or at least every other day, and if this regime is followed antifungal chemicals are not needed. Eggs will hatch in two to six weeks depending on species and storage temperature. Newly hatched brine shrimp can be fed from the first day through adulthood.

Common Challenges

Maintaining clean egg-storage water with frequent changes prevents fungus without chemicals. As a surface predator the adult will take fry and small tankmates, so eggs and young are best reared away from the parents.