Killifish Australe

The Lyretail Killifish (Aphyosemion australe) has been captivating aquarists since it first appeared in the hobby in the early twentieth century. A fixture of killifish collections around the world, it remains one of the most sought-after African killifish for its spectacular appearance and manageable care requirements. It is native to the coastal lowland forests of Gabon, southern Cameroon, and northern Congo, where it inhabits cool, shaded forest streams and swamps carpeted in leaf litter and decaying plant matter.

The male's finnage is the defining feature: the caudal fin extends into long, flowing lobes top and bottom — the lyre shape from which it takes its common name. The body is adorned in a base of rich orange-brown overlaid with a fine scatter of red and blue spots and streaks, with iridescent blue-green accents on the gill covers and flanks. Females are plainer in brown with less pronounced spotting, as is typical in this genus.

Aphyosemion australe is a non-annual killifish — it does not require a dry season for egg development and can live for 2–3 years under good conditions. This makes it significantly more straightforward than annual killifish species. Eggs are deposited among fine plants or spawning mops and hatch in 2–3 weeks without a diapause requirement, simplifying the breeding process considerably.

Cool, clean water and a varied diet of small live and frozen foods are the keys to maintaining this species at its best. Its preference for cooler temperatures sets it apart from many tropical species and requires attention to summer tank temperature management.

Tank Setup House a pair or trio in a 40-liter or larger planted aquarium. Dense planting with Java moss, fine-leaved plants, and floating vegetation creates an ideal environment. Use a dark substrate and subdued lighting to bring out coloration and reduce stress. Gentle sponge filtration maintains water quality without disturbing the fine substrate or delicate fins.

Water Parameters Maintain pH between 6.0 and 7.5 with temperatures of 18°C to 23°C. This species prefers cooler temperatures than most tropical fish — summer management may require a fan or chiller in warmer climates. Soft, slightly acidic water is ideal. Perform 20–25% water changes weekly.

Diet Carnivorous. Feed a varied diet of live and frozen small invertebrates: daphnia, baby brine shrimp, micro worms, and bloodworms. Small high-quality flake or pellets may supplement but should not dominate the diet. Feed small amounts twice daily.

Compatibility Peaceful and best housed in species-specific aquaria to protect delicate fins from nippers and to allow natural behavior observation. Can be kept with very small, docile species if necessary. Avoid boisterous or fin-nipping fish. Males may spar but rarely cause serious damage in spacious tanks.

Breeding Deposits eggs in fine plants or wool spawning mops over several weeks. Collect eggs every few days and hatch in shallow, clean water. Eggs hatch in 14–21 days at appropriate temperatures. Fry are large and accept micro worms and baby brine shrimp immediately.

Health Notes Sensitive to elevated temperatures — prolonged exposure above 24°C shortens lifespan. Secure lid essential as all killifish are jumpers. Watch for bacterial infections if water quality lapses.