Jewel killifish

Aphyosemion exiguum

Also known as Exiguum killi

FreshwaterFish

Care at a glance

Temperature: 68–77°F (20–25°C)
pH: 5.5–7.0
Adult size: 1.6 in (4 cm)
Minimum tank: 11 gal (40 L)
Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Cameroon and Gabon forest brooks
Family: Nothobranchiidae

Overview

The jewel killifish is a tiny forest Aphyosemion kept as a single pair or a trio of one male and two females. It swims in the middle water of a small, dim, densely planted tank, and a tight lid keeps it from jumping out. It is mostly peaceful and shy, best on its own or with very small, gentle tankmates that will not outpace it at feeding time. Feed fine live and frozen foods such as cyclops, daphnia, baby brine shrimp, and micro bloodworm, which suit its small mouth. A pair or trio is comfortable in a tank of about 40 liters, and it shows its green-gold colour best when kept cool, dim, and undisturbed.

In the wild

The jewel killifish lives in small, shaded forest brooks and trickles across Cameroon and Gabon, shallow, cool, soft waters running over sand and leaf litter. Recreate that with a dark base, roots, leaf litter, floating plants for shade, and only gentle flow. Keep the water soft and acidic to neutral, about pH 5.5–7.0, and cool to warm at 20–25 C, the low, still conditions this small fish prefers.

Good to know

Aphyosemion exiguum is a non-annual member of the family Nothobranchiidae and one of the smallest in its genus, reaching only about 4 cm. As a plant spawner it lays eggs among fine vegetation that develop in water rather than dry mud, and its small size and shy nature keep breeding at a moderate level. Its name, from the Latin for small or meagre, simply records how little the fish is.

Did you know

The species name exiguum is Latin for scanty or slight, and it was chosen for the fish itself: at around four centimetres it is one of the smallest of all the Aphyosemion killifish.

Tank mates

Jewel killifish is a mostly peaceful, social species that keeps to the middle. These picks match on water type, temperature, pH, size and temperament.