Cinnamon Killie (Aphyosemion cinnamomeum) — 3-4cm

Overview

The Cinnamon Killie (Aphyosemion cinnamomeum) is a small, elegant West African killifish prized for its warm cinnamon tones, delicate finnage, and peaceful temperament. Reaching just 3.5cm in length, this species is ideal for planted nano aquariums and dedicated species tanks. Native to forested freshwater habitats in equatorial West Africa, Aphyosemion cinnamomeum thrives in soft, slightly acidic water with gentle filtration and live foods. Available for sale UK from Tropical Fish Co, this rare killifish rewards patient keepers with subtle beauty and fascinating breeding behaviour.

Appearance and Coloration

The Cinnamon Killie displays warm, earthy colouration with a slender body adorned in shades of cinnamon, amber, and soft gold. Males are more intensely coloured than females, with elongated dorsal and anal fins often highlighted by subtle red or orange edging. The finnage features intricate patterns and iridescent highlights that shimmer under subdued lighting. Females are smaller, plumper, and more subdued in colour. In a well-planted tank with dark substrate and tannin-stained water, the colours become even more vibrant and eye-catching.

Natural Habitat

Aphyosemion cinnamomeum inhabits shallow, slow-moving streams, swamps, and seasonal pools in the forested regions of equatorial West Africa. These biotopes are characterised by soft, acidic, tannin-rich water, dense vegetation, submerged roots, and abundant leaf litter. Water flow is minimal, and the substrate consists of mud, sand, and organic debris. During the wet season, these fish spawn among fine-leaved plants or submerged vegetation; during the dry season, some populations may experience reduced water levels or temporary habitat desiccation.

Aquarium Setup

A minimum 40-litre aquarium is recommended for a pair or small group of Cinnamon Killies. Use a fine sand substrate with plenty of live plants such as Cryptocoryne, Java moss, Microsorum, and floating species like Limnobium or Salvinia. Add dried leaves (Indian almond or oak) to release tannins and replicate the natural blackwater environment. Provide spawning mops or fine-leaved plants for egg deposition. Lighting should be dim, and filtration gentle to avoid strong currents. A secure, tight-fitting lid is essential, as killifish are excellent jumpers.

Feeding and Diet

As a carnivore, Aphyosemion cinnamomeum requires a varied, protein-rich diet to maintain health and colour. Offer small live or frozen foods such as daphnia, baby brine shrimp, grindal worms, microworms, and bloodworms daily. High-quality micro-pellets or flakes may be accepted, but live and frozen foods are essential for conditioning and breeding. Feed small portions twice daily, removing uneaten food promptly to maintain pristine water quality. Variety and freshness are critical for optimal health and vibrant colouration.

Behaviour and Temperament

The Cinnamon Killie is a peaceful, shy species that spends most of its time in the upper and middle water column among plants. Males may display to each other with flared fins and subtle posturing, but serious aggression is rare. These fish are most active during dawn and dusk, and they appreciate dimly lit aquariums with plenty of cover. They are not competitive feeders, so avoid housing them with boisterous or fast-moving species. In a well-planted species tank, they display natural behaviours and may spawn regularly.

Suitable Tank Mates

Aphyosemion cinnamomeum is best kept species-only or with very small, calm fish that share similar water requirements. Suitable companions include tiny rasboras like Boraras species or Microdevario in larger, heavily planted tanks. Avoid active community fish, large fish, aggressive species, fin-nippers, fast boisterous species, and species that require hard alkaline water. A calm, quiet environment is essential for this delicate killifish to thrive and display its full range of colours.

Breeding

This typically plant-spawning annual/non-annual killifish lays eggs among fine-leaved plants, spawning mops, or moss. Condition a pair or small group with high-quality live foods, then provide spawning media such as Java moss or yarn mops. Eggs are usually removed and incubated separately in moist or water-based conditions depending on the method and strain. Fry are tiny and require infusoria or liquid fry food initially, graduating to newly hatched brine shrimp after a few days. Remove adults to prevent egg predation. Breeding success is highest in soft, slightly acidic water.

Why Buy from Tropical Fish Co

Tropical Fish Co is a trusted UK supplier of rare and specialist tropical fish, including hard-to-find killifish species like Aphyosemion cinnamomeum. We guarantee healthy, well-conditioned stock, expert care advice, and secure nationwide delivery. Every fish is quarantined and inspected before dispatch, ensuring you receive only the finest specimens. Whether you're setting up a dedicated killifish tank or adding a rare species to your collection, Tropical Fish Co offers unmatched quality and customer service. Order online today and bring the beauty of West African forests into your home aquarium.