Gardner's Killifish (Fundulopanchax gardneri) — 3cm

Overview

The Gardner's Killifish (Fundulopanchax gardneri), also known as the Blue Lyretail or Steel-Blue Aphyosemion, is a striking, hardy killifish with shimmering blue coloration and elegant lyretail finnage that adds movement and color to smaller aquariums. Endemic to freshwater habitats in Nigeria and Cameroon, this species inhabits slow-moving streams and pools with abundant vegetation, where it feeds on small invertebrates and insect larvae. Reaching 7cm in adulthood with moderate care requirements, the Gardner's Killifish is suitable for aquarists who can provide cooler water temperatures (20-24°C) and a calm, planted environment. Available to buy killifish online uk from Tropical Fish Co, this beautiful species rewards dedicated keepers with fascinating breeding behavior and stunning finnage displays.

Appearance

Adult Gardner's Killifish reach approximately 7cm in length, displaying a streamlined, elongated body typical of killifish species. Males are particularly striking, with shimmering blue coloration covering the body and spectacular lyretail finnage with extended filaments. Females are typically more subdued in coloration but share the species' elegant body shape. The blue iridescence intensifies under optimal conditions and during breeding displays, making males unmistakable in the aquarium. The species' graceful finnage and active swimming behavior create constant visual interest.

Natural Habitat

This species is endemic to freshwater habitats in Nigeria and Cameroon, where it inhabits slow-moving streams, pools, and swamps with soft, slightly acidic water. In the wild, Gardner's Killifish shelter among dense vegetation and surface cover, emerging to feed on small invertebrates, insect larvae, and mosquito larvae at the water's surface. The water in these habitats is typically warm but cooler than many tropical species (20-24°C), soft, and tannin-stained from decomposing organic matter. Replicating these calm, planted conditions in captivity supports the species' health and natural behavior.

Aquarium Setup

A minimum tank size of 60 litres is suitable for a small group of Gardner's Killifish, providing adequate space for territorial behavior without overcrowding. Structure the aquarium with abundant plants, including floating vegetation to provide surface cover and spawning sites. Use driftwood, leaf litter, and subdued lighting to create a calm, naturalistic environment that replicates the species' shaded forest pool habitat. Provide a sandy or dark substrate to enhance the species' coloration. Ensure a tightly fitting lid, as killifish are excellent jumpers and will escape through even small gaps. Gentle filtration with minimal water flow is ideal, as this species prefers calm conditions.

Water Parameters

This species requires soft, slightly acidic to neutral water with cooler temperatures than many tropical species. Target pH between 6.0 and 7.5, with temperatures stable between 20-24°C—significantly cooler than standard tropical setups. Water hardness should be low to moderate (3-10 dGH). Perform weekly water changes of 25-30% to maintain stable chemistry and excellent water quality. Test parameters regularly using liquid test kits, and avoid sudden fluctuations. The species is sensitive to poor water quality—ammonia and nitrite must always be zero. Cooler temperatures mean a heater may not be required in many UK homes, especially in summer.

Feeding

Fundulopanchax gardneri is a carnivore that feeds on small invertebrates, insect larvae, and surface-dwelling prey in the wild. In captivity, offer a varied, protein-rich diet of high-quality micro pellets as a staple, supplemented regularly with frozen or live foods such as daphnia, brine shrimp, bloodworms, and mosquito larvae. Live or frozen foods bring out the species' best coloration and condition for breeding. Feed small portions once or twice daily at the water's surface, where killifish naturally feed. Avoid flake foods that sink quickly, as killifish are primarily surface feeders and may not forage from the substrate.

Behaviour

This species displays semi-aggressive behavior, particularly among males during territorial displays and spawning. Males establish territories around preferred areas and may display assertively to rivals, though aggression is generally manageable in appropriately sized aquariums with ample cover. The species is active, alert, and constantly patrols the upper water column, often hovering just below the surface. Males display their spectacular finnage to attract females and intimidate rivals. Despite the semi-aggressive temperament, Gardner's Killifish are generally peaceful toward non-conspecifics and suitable for calm community setups with appropriate tankmates.

Tank Mates

Compatible tank mates include peaceful, similarly sized fish that tolerate cooler water temperatures and are not fin-nippers or overly active. Suitable options include small peaceful cyprinids, peaceful bottom-dwellers, and peaceful snails. Avoid housing with large or aggressive fish, fin-nippers, very active fast-feeding species that may outcompete the killifish during feeding, or species requiring warmer tropical temperatures (above 24°C). Tiny shrimp and fry may be eaten. The species' cooler temperature requirements limit tankmate options, so research carefully before adding companions.

Breeding

Gardner's Killifish spawn readily in soft to moderately hard water, making them one of the easier killifish species to breed. Spawning usually occurs among fine-leaved plants or spawning mops, with eggs laid individually and attached to vegetation. Remove eggs or separate the breeding pair after spawning, as adults may eat eggs and fry. Eggs can be incubated separately in shallow containers with gentle aeration until hatching. Fry are small and require infusoria or liquid fry foods initially, progressing to newly hatched brine shrimp as they grow. Provide stable water conditions and excellent nutrition to raise healthy fry.

Why Buy from Tropical Fish Co

At Tropical Fish Co, we specialize in rare and unusual species, including beautiful killifish like the Gardner's Killifish. Our fish are carefully quarantined and conditioned to ensure they arrive in excellent health, ready to thrive in your planted aquarium. We provide expert guidance on water chemistry, aquarium setup, and breeding to help you succeed with these stunning fish. With reliable UK delivery and a commitment to quality, we're your trusted source for rare freshwater fish uk and specialist killifish for sale uk.