Aphyosemion australe (Golden Lyretail Killifish)

Overview

The Golden Lyretail Killifish (Aphyosemion australe), often referred to as the Kap Lopez Killifish, is a captivating freshwater species. The "Gold" or "Hjersseni" variant is a selectively bred, aquarium-strain coloration of the wild form, which is typically browner. Known for its hardiness compared to other killifish, it is a non-annual species, meaning it does not die off after a single dry season in the wild, making it a wonderful long-term resident for dedicated aquarists.

Distribution and Habitat

The wild Aphyosemion australe is native to the coastal regions of West Africa, specifically Gabon around the Cape Lopez area. They naturally inhabit swamps, slow-moving streams, and shallow pools under the thick canopy of the rainforest. These waters are heavily shaded, extremely soft, and acidic due to the accumulation of decaying organic matter like leaves and wood. The golden variant, however, was developed in captivity and is not found in the wild.

Description of Golden Lyretail Killifish

Body shape:

They possess a slender, elongated, and somewhat cylindrical body, typical of many surface-dwelling killifish, allowing them to navigate through dense vegetation with ease.

Color:

The males exhibit a breathtaking bright orange-gold base color, heavily speckled with contrasting deep red spots and streaks along the flanks. Females are generally paler, exhibiting a subdued yellow-brown hue with fewer spots.

Barbels:

This species does not possess any barbels.

Snout:

They have a pointed snout with a distinctively upturned mouth, perfectly adapted for snatching insects and larvae from the water's surface.

Eyes:

The eyes are relatively large with a dark pupil, often surrounded by a reflective golden or orange rim.

Fins:

The dorsal and anal fins are set far back on the body and are highly extended in males. They feature striking red sub-marginal bands bordered by bright white tips.

The Tail:

The caudal fin (tail) is the defining feature of the males, boasting a beautiful lyre shape with elongated upper and lower rays that are tipped in white and red.

Temper

This species is generally peaceful and makes a good addition to a carefully planned community tank. However, males can be territorial and display mild aggression towards one another, especially in smaller setups.

Sociality

They are best kept in pairs or small harems consisting of one male and multiple females. This helps to disperse the male's breeding attention and reduces stress on individual females. They can be kept with other small, peaceful, and slow-moving fish.

Activity

They are moderately active and spend the majority of their time in the middle and upper levels of the aquarium. They are also known to be excellent jumpers, especially when startled.

Keeping and Caring for Golden Lyretail Killifish

Tank size:

A minimum tank size of 20 liters (5 gallons) is sufficient for a single pair. However, a 40-liter (10-gallon) or larger aquarium is highly recommended if you plan to keep a harem or a small community.

Water Parameters:

Temperature

They thrive in slightly cooler tropical temperatures ranging from 21°C to 26°C (70°F - 79°F).

pH

The water should be slightly acidic to neutral, ideally between 5.5 and 7.0.

Hardness

They prefer soft water, with a general hardness (dGH) ranging from 1 to 10.

Ammonia, Nitrite, Nitrate

Ammonia and Nitrite must always be at 0 ppm. Nitrates should be kept as low as possible, ideally below 20 ppm, through regular water changes.

Lighting

Dim to moderate lighting is preferred to mimic their natural, shaded rainforest habitat. Floating plants can be used to diffuse bright aquarium lights.

Water flow

Water movement should be kept to a minimum. Gentle filtration, such as a sponge filter, is ideal as they do not appreciate strong currents.

Decorations and Plants

A heavily planted tank is highly recommended. Use fine-leaved plants like Java Moss, Water Sprite, and floating plants. Driftwood and dried Indian Almond leaves (catappa) can be added to release tannins, which tint the water and lower the pH. A tight-fitting lid is absolutely essential to prevent them from jumping out.

Diet

In nature, they are micro-predators feeding on insects, larvae, and small crustaceans. In the aquarium, they are primarily carnivorous and require a protein-rich diet.

Some Feeding Tips

While they may accept high-quality crushed flakes or micro-pellets, their diet should heavily feature live or frozen foods. Offer them bloodworms, daphnia, brine shrimp, and mosquito larvae to ensure optimal health and vibrant coloration.

Breeding

Breeding the Golden Lyretail Killifish is relatively easy. They are plant spawners that lay adhesive eggs continuously over several days. Provide a spawning mop or dense clumps of Java Moss. The eggs can be left in the tank if it is heavily planted, but for a higher survival rate, the mop or moss should be removed to a separate rearing container. Depending on temperature, eggs incubate in water for 14 to 21 days before hatching. Fry can be fed infusoria or liquid fry food initially, graduating to freshly hatched baby brine shrimp.

Conclusion

The Golden Lyretail Killifish is a magnificent and rewarding fish for both intermediate and experienced aquarists. Their breathtaking golden-orange coloration, elegant finnage, and fascinating behaviors make them a standout species. By providing a secure, well-planted environment with gentle water parameters and a high-quality diet, you can enjoy these beautiful non-annual killifish for years to come.