Lyretail Killifish (Aphyosemion australe)

The Lyretail Killifish, Aphyosemion australe, is one of the most beloved species within the diverse Killifish family. Known for its graceful fin extensions, striking colours, and peaceful temperament, this species is an excellent choice for aquarists looking to add beauty and elegance to a freshwater aquarium. As a member of the genus Aphyosemion, it shares ancestry with a large group of African killifish species found throughout forested and swampy regions of the continent. Relatives include Aphyosemion striatum, Aphyosemion gardneri, and several other widely kept freshwater killi varieties.

Native Habitat

originates from West Africa, particularly in Gabon and the Congo region, where it inhabits slow-moving shaded streams, marshes, and shallow forest pools. These waters are naturally soft, acidic, and filled with leaf litter, providing a calm and dim environment that the Lyretail Killifish has adapted to over generations.

Size and Appearance

Adult Lyretail Killifish typically reach around 5 cm (2 inches) in length. Their signature trait is the elongated caudal fin that forms a lyre shape. Males display richer, more vibrant colours—usually deep orange or chocolate-brown with blue or red spotting—while females are smaller and more subdued in tone.

Albino Variation

Albino Lyretail Killifish are a popular aquarium variant. They display a creamy body colour with red eyes and often have enhanced orange or pink tones in the fins. Care requirements remain identical to the wild-coloured form, though albinos benefit from lower lighting due to increased light sensitivity.

Diet and Feeding

In the wild, this species consumes small insects, larvae, and micro-crustaceans. In the aquarium, they thrive on:

High-quality micro-pellets
Frozen foods such as daphnia, cyclops, and bloodworms
Live foods like brine shrimp or mosquito larvae

Providing a varied diet helps maintain their bright coloration and overall vitality. For additional feeding guidance, see our nutrition articles such as the benefits of frozen mysis shrimp and complete fish feeding nutrition guide.

Temperament and Community Compatibility

Lyretail Killifish are peaceful and generally calm fish, making them suitable for community aquariums with equally gentle tank mates. Avoid overly active or fin-nipping species that may stress them or damage their delicate fins. Suitable tank mates include small tetras (such as Neon Tetras), Corydoras catfish (try the Panda Cory), and peaceful rasboras.

Water Conditions

To keep Aphyosemion australe healthy, aim to recreate the soft, acidic waters of their native habitat. Recommended parameters include:

Temperature: 20–24°C (68–75°F)
pH: 5.8–7.0
Hardness: Soft to moderately soft water

Low lighting and dark substrates help them feel secure. Ensure your aquarium is fully cycled — see our guide on maintaining clear, healthy tank water.

Ease of Care

The Lyretail Killifish is considered moderately easy to care for, especially when kept in a peaceful, well-maintained aquarium. They do best in planted tanks with subdued lighting, floating plants, and gentle water flow. Beginners can succeed with this species by keeping them in stable water conditions and ensuring proper feeding habits.

Sexing

Sexing Aphyosemion australe is straightforward:

Males: Brighter colours, longer lyre-shaped tail extensions, more elongated dorsal and anal fins.
Females: Smaller, rounder bodies, shorter fins, and more muted colours.

Breeding the Lyretail Killifish

Breeding this species is considered easy compared to many other killifish. They are egg-scattering fish and readily spawn in aquariums with the right setup. Use fine-leaved plants such as java moss or spawning mops. Eggs typically hatch in 12–21 days depending on temperature. Parents may eat the eggs, so many breeders separate the eggs into a rearing container.

Species Variations and Relatives

Within the Aphyosemion genus, many species share similar care requirements and body shapes. Popular relatives include:

Aphyosemion striatum
Aphyosemion gardneri
Aphyosemion bivittatum

These species also appreciate soft water, peaceful tank mates, and planted setups. Some relatives may be featured under our freshwater fish species section.

Ideal Aquarium Setup

A 10–20 gallon aquarium is sufficient for a small group of Lyretail Killifish. They excel in planted tanks rich in hiding spots, floating plants, and gentle flow. If you need help selecting or planning an aquarium, consider our guides on choosing the right aquarium size and setting up your first freshwater aquarium.

Frequently Asked Questions

How long do Lyretail Killifish live?

They typically live 2–3 years in captivity, though excellent water quality and varied diets may extend their lifespan.

Can Lyretail Killifish live in a community tank?

Yes, but only with peaceful tank mates. Avoid fin-nippers and overly active fish. Small tetras, rasboras, and Corydoras species make ideal companions.