Lyretail Killifish Care Guide - Aquarium Setup, Diet & Breeding

Lyretail Killifish are elegant, small freshwater fish named for the male’s distinctive lyre-shaped tail, which is edged in warm yellow and orange. Males typically display copper, orange and blue-green tones across the body, while the fins carry attractive dark edging and delicate filamentous extensions. Females are more subdued, but their rounded shape and gentle gold-brown colouring are appealing in their own right.

This species is peaceful and generally calm, although males may spar with one another through displays and short chases. They spend much of their time in the upper and middle levels of the aquarium, where they inspect cover and watch for food. Their habit of leaping makes a secure cover especially important.

In the wild, Aphyosemion australe lives in cool, shaded forest waters with soft, acidic conditions. These habitats can include small streams, pools and seasonal waters surrounded by dense vegetation, roots and fallen leaves. The broken light and dark background help the fish feel secure and enhance their colours.

The Lyretail Killifish is a non-annual killifish, meaning its eggs do not require a prolonged dry period to develop. Its manageable size, striking males and interesting breeding behaviour have made it a popular choice for aquarists who enjoy smaller, less conventional community fish.

Lyretail Killifish come from coastal West-Central Africa, particularly the forest streams, swamps and temporary waters of Gabon, with populations also recorded in nearby Cameroon and Equatorial Guinea. They inhabit shaded, slow-moving freshwater environments rich in leaf litter and vegetation.

A 40-litre aquarium is a practical minimum for a small group, with a footprint of about 60 x 30 cm providing useful swimming space and room for plants. Use a tightly fitting lid because Lyretail Killifish are accomplished jumpers. Dense planting, floating plants, driftwood, roots and shaded areas create the cover they prefer, while an open surface area allows feeding. A dark, fine-grained substrate, gentle filtration and subdued lighting suit their forest-stream character; leaf litter can add natural cover, provided it is clean and replaced as it decomposes. Aim for roughly 20–24°C and a pH of 6.0–7.0.

Males reach up to about 6 cm (2.4 in) in total length, while females are usually smaller at around 5–5.5 cm (2.0–2.2 in).

These carnivorous-leaning micro-predators enjoy a varied diet of small live and frozen foods, including baby brine shrimp, daphnia, mosquito larvae, grindal worms and bloodworms. They will also accept quality small pellets or flakes, though variety helps maintain condition and colour. Feed small portions once or twice daily, taking care not to leave uneaten food on the substrate.

Lyretail Killifish can share an aquarium with similarly peaceful, small fish such as ember tetras, small rasboras, pencilfish, pygmy corydoras and other gentle dwarf community species. Small freshwater shrimp may be tolerated, although newly hatched shrimplets can be eaten. Avoid fin-nipping barbs, boisterous or much larger fish, and aggressive species. Keeping more than one male requires plenty of plants and visual barriers; a single male with two or more females is often the most harmonious arrangement.

Lyretail Killifish are relatively straightforward to breed in a mature, species-focused aquarium. Offer spawning mops made from fine wool or dense plants, where a pair or small group can deposit adhesive eggs. Remove the mop and incubate it separately in clean, softly acidic water; the eggs generally hatch after around two to three weeks. Feed the tiny fry infusoria or commercially prepared first foods, followed by baby brine shrimp as they grow. Adults may eat eggs and fry, so separation improves survival.

Males are larger and much more vividly coloured, with copper-orange bodies, blue-green markings and elongated, lyre-shaped extensions on the caudal fin. Females are smaller, rounder and usually brownish or golden-grey, with shorter, less ornate fins.