Green Fire Tetra (Aphyocharax rathbuni) Care Guide
An underrated South American tetra with a translucent green body that shimmers in good lighting and a vivid red-orange belly that intensifies with proper diet and water conditions.
Compiled by Aquairi from published sources · Published · Updated
Overview
Aphyocharax rathbuni is a species in the family Characidae. An underrated South American tetra with a translucent green body that shimmers in good lighting and a vivid red-orange belly that intensifies with proper diet and water conditions. Hardy, active, and easy to breed, it deserves more popularity in the hobby. Does best in well-planted tanks with open swimming space.
Taxonomy
- Family: Characidae
- Genus: Aphyocharax
- Scientific name: Aphyocharax rathbuni
- Other names: Aphyocharax rathbuni, Rathbun's Bloodfin
- Origin: South America
Habitat
Native to the Río Paraguay basin of Paraguay and adjacent Brazil and Argentina. Inhabits clear and slightly turbid streams and floodplain margins. Mature males develop iridescent green flanks and red fin edges; a small, active shoaling characin.
Tank requirements
- Minimum tank volume: 60 L
- Temperature: 22-28 °C
- pH: 5.5-7.5
- GH: 2-15 °dGH
- Water flow: moderate
- Adult size: 3-4 cm
- Lifespan: 3-5 years
- Recommended group size: ≥ 6
- Difficulty: beginner
Diet
Classified as omnivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.
Compatibility
- Temperament: peaceful
- Swimming level: middle
- Compatible tank mates: Corydoras, Rasboras, Other Tetras, Dwarf Cichlids, Cherry Shrimp
- Avoid with: Large predatory fish, Very slow long-finned fish
Breeding
- Breeding strategy: egg-scatterer
- Breeding difficulty: beginner
Green Fire Tetra Breeding Guide
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.