Green Fire Tetra Breeding Guide

Breeding Aphyocharax rathbuni: sexing, conditioning on livefoods, a productive group egg-scatter of around 500 eggs into fine plants, and rearing the fast-growing fry.

Overview

Aphyocharax rathbuni is a small characid endemic to the Paraguay, Parana and Uruguay river drainages. It is a productive, group-spawning egg-scatterer regarded as a beginner-level breeding subject, making it a good first project for an aquarist new to breeding tetras.

Sexing

Females become noticeably fuller-bodied when in spawning condition, which is the easiest way to distinguish a ripe female from a male.

Conditioning

Condition the adults well in the main tank with a plentiful supply of bloodworm, brine shrimp and other livefoods. Some aquarists condition the sexes separately so that spawning occurs only in the designated breeding tank. General parameters are a temperature of 20-26 degrees Celsius and pH 6.5-7.5.

Breeding Setup

Use a breeding tank well planted with fine-leaved plants such as Cabomba or Java moss to give the adhesive eggs refuge. An air-driven sponge filter is sufficient, and minimal or no lighting is preferable. For breeding, soft water at a pH of around 6.5 is recommended.

Spawning Behavior & Trigger

These are group-spawning egg-scatterers. Spawning typically begins within 24 hours of placement in the breeding tank, often in the early morning, with around 500 eggs produced in a spawning event scattered among the plants.

Egg & Fry Care

Eggs hatch in 2-3 days, and the fry become free-swimming 4-5 days after hatching. Begin feeding with infusoria, then move on to newly hatched brine shrimp and powdered foods. Growth is fairly rapid with regular water changes, so the fry move through their first foods quickly and soon take larger fare. Keeping the spawning tank dimly lit during the egg and early-fry stages, with the air-driven sponge filter providing gentle circulation, protects the developing eggs and the tiny first-feeding fry.

Common Challenges

As with other egg-scatterers, the adults should be removed after spawning to prevent them eating the eggs, and dense fine-leaved cover protects the clutch. The very small free-swimming fry need genuinely small first foods such as infusoria before brine shrimp. The species' productivity is an advantage, with around 500 eggs per spawning event, but it also means the rearing tank must keep pace with a large number of fry; regular small water changes support the fairly rapid growth reported. Conditioning the sexes separately beforehand and providing soft water at a pH of around 6.5 makes spawning, which usually begins within 24 hours of introduction and often in the early morning, both prompt and predictable.